Home Journals Articles Updates About
CN
image
收藏切换
Study on the mechanism of low-temperature CO2 methanation catalyzed by LaNiO3/CeO2
收藏切换
PDF
Ji LIU1, Xuguang ZHANG1, Mengfan LIU1, Zhi ZHOU2, Wentao LI1, 2, Bin HU1, *, Zhenxi ZHANG1, Qiang LU1, *
Journal of Fuel Chemistry and Technology | 2026, 54(8) : 20250320-1646 - 20250320-1656
Less
收藏切换
Journal of Fuel Chemistry and Technology | 2026, 54(8): 20250320-1646-20250320-1656
• RESEARCH PAPER •
Study on the mechanism of low-temperature CO2 methanation catalyzed by LaNiO3/CeO2
Full
Ji LIU1, Xuguang ZHANG1, Mengfan LIU1, Zhi ZHOU2, Wentao LI1, 2, Bin HU1, *, Zhenxi ZHANG1, Qiang LU1, *
Affiliations
  • 1National Engineering Research Center of New Energy Power Generation, North China Electric Power University, Beijing 102206, China
  • 2PowerChina Northwest Engineering Corporation Limited, Xi’an 710065, China
Published: 2026-08-10 doi: 10.1016/S1872-5813(26)60662-7
Outline
收藏切换

Perovskite-type catalysts have exhibited significant potential for CO2 methanation. However, their efficacy at low temperatures and the underlying catalytic mechanisms remain inadequately understood. In this study, a perovskite catalyst LaNiO3/CeO2 was successfully constructed via the sol-gel method combined with an impregnation process. By comparing the physicochemical properties and catalytic activity of LaNiO3, LaCeNiO4, Ni/CeO2 and La-Ni/CeO2 catalysts, the underlying mechanism for the low-temperature CO2 methanation catalyzed by LaNiO3/CeO2 was elucidated. During reduction, the LaNiO3 perovskite structure in situ decomposed to generate highly dispersed and small-sized Ni0 particles with an average diameter of 12.6 nm. The CeO2 support provided abundant oxygen vacancies (Ce3+/(Ce3++Ce4+) ratio of 9.2%) as well as weak and moderate basic sites, synergistically promoting CO2 adsorption and activation. The interaction between the active phase and the CeO2 support further stabilized the dispersion of Ni0 and optimized the surface basicity and oxygen vacancy concentration. Under catalytic conditions at 200−300 °C, LaNiO3/CeO2 exhibited nearly 100% selectivity toward CH4, while CO2 conversion increased monotonically to 23.6%. This study clarified the crucial role of the perovskite pre-structuration and in situ reduction strategy in regulating the dispersion of active metals and the catalyst structure, laying a theoretical foundation for the design of catalysts for low-temperature CO2 methanation.

carbon dioxide hydrogenation  /  low-temperature methanation  /  Ni-based catalysts  /  perovskite-type oxide  /  CeO2 support
刘吉, 张绪广, 刘梦帆, 周治, 李文涛, 胡斌, 张镇西, 陆强. LaNiO3/CeO2催化CO2低温甲烷化的作用机制研究. 燃料化学学报（中英文）, 2026 , 54 (8) : 20250320-1646 -20250320-1656 . DOI: 10.1016/S1872-5813(26)60662-7
Ji LIU, Xuguang ZHANG, Mengfan LIU, Zhi ZHOU, Wentao LI, Bin HU, Zhenxi ZHANG, Qiang LU. Study on the mechanism of low-temperature CO2 methanation catalyzed by LaNiO3/CeO2[J]. Journal of Fuel Chemistry and Technology, 2026 , 54 (8) : 20250320-1646 -20250320-1656 . DOI: 10.1016/S1872-5813(26)60662-7
Full Text
Less
Excessive carbon dioxide (CO2) emissions have triggered severe environmental issues such as global warming and increased frequency of extreme weather events[1−2]. It is urgently necessary to effectively curb the excessive CO2 emissions and develop technologies for its resource utilization. CO2 hydrogenation into methane (CH4) is one of the key pathways for CO2 resource utilization[3]. Developing efficient catalysts is crucial to overcoming the kinetic limitations of the inert CO2 methanation reaction. Ni-based catalysts demonstrate promising potential for CO2 methanation due to their favorable catalytic performance and relatively low cost.
In practical applications for CO2 methanation, Ni-based catalysts commonly encounter issues such as agglomeration and sintering of Ni particles, which leads to catalyst deactivation. The incorporation of promoters (such as Ca[4], Mg[5], Ru[6] and La[7]) can optimize the metal dispersion, Ni-support interaction, and stability of Ni-based catalysts. Among them, La is an excellent promoter that can effectively improve the dispersion of Ni species, modify the electronic environment of Ni particles, and enhance the surface basicity of the catalyst, thereby facilitating the activation of CO2. Garbarino et al.[8] synthesized a La-doped Ni/γ-Al2O3 catalyst, in which La notably improved the catalytic activity of Ni/γ-Al2O3, while the catalyst maintained high selectivity toward CH4 even at a reaction temperature of 400 °C. After H2 reduction, this structure promoted the formation of Ni0 particles with smaller size and favorable dispersion, thereby enhancing the reaction efficiency. Notably, the perovskite-type oxide structure formed by La and Ni promoted the reaction, since it allowed Ni0 particles to attain smaller size and better dispersion after H2 reduction[9]. Alkhoori et al.[10] reported that the LaNiRuO3 perovskite-type catalyst achieved 67% CO2 conversion and over 92% CH4 selectivity in CO2 methanation at 450 °C.
Selecting a suitable support is a key factor in enhancing the activity of Ni-based catalysts. CeO2 is a basic oxide that can enhance CO2 adsorption, thereby providing favorable conditions for CO2 activation and exhibiting significant potential in CO2 methanation[11]. In addition, a strong electronic interaction between Ni and CeO2 facilitates electron transfer from Ni to the CeO2 4f orbital, which promotes the reduction of Ce4+ to Ce3+ and forms non-stoichiometric CeO2−x (0 ≤ x ≤ 0.5). This process generates abundant oxygen vacancies that are endowed with exceptional activity for activating CO2[12]. Consequently, CeO2-supported Ni-based catalysts exhibit high CO2 conversion and CH4 selectivity in CO2 methanation reactions. Perovskite-type oxides combined with CeO2 supports, which possess excellent oxygen storage capacity, exhibit highly efficient methanation catalytic performance. Jon et al.[13] synthesized a LaNiO3/CeO2 catalyst that demonstrated excellent catalytic activity. LaNiO3 promoted the high dispersion of Ni nanoparticles and strong interfacial interactions, while the oxygen vacancies and surface basicity of CeO2 further enhanced the activation efficiency of CO2.
Although perovskite-type catalysts show significant potential for CO2 methanation, current research has primarily focused on high-temperature reaction conditions, and the underlying mechanisms involving both the perovskite structure and the support in the methanation reaction remain to be further elucidated. Herein, a LaNiO3/CeO2 catalyst was prepared via the perovskite pre-structuration and in situ reduction strategy, with its low-temperature (≤300 °C) methanation activity as the focus. For comparison, four additional catalysts were also synthesized, namely LaNiO3, LaCeNiO4, Ni/CeO2 and La-Ni/CeO2. The perovskite structure, the Ni-La interaction, the CeO2 support, and the active-component-support interaction were investigated via comparative activity evaluation and characterization. This work seeks to unravel their combined mechanistic contributions to the enhanced low-temperature methanation activity of LaNiO3/CeO2.
1　Experimental
Less
1.1　Materials
All chemicals and reagents, including Ce(NO3)3·6H2O (purity > 99.0%), La(NO3)3·6H2O (purity > 99.0%), Ni(NO3)2·6H2O (purity > 99.0%), citric acid (purity > 99.5%) and ethylene glycol (purity > 99.0%), were purchased from Shanghai Aladdin Biochemical Technology Co., Ltd and used without further purification.
1.2　Preparation of catalysts
LaNiO3 was synthesized as follows. 0.3680 g of La(NO3)3·6H2O and 0.2477 g of Ni(NO3)2·6H2O were dissolved in 40 mL of deionized water. To this solution, 0.3266 g of citric acid (CA) and 95 μL of ethylene glycol were added, corresponding to a molar ratio of ethylene glycol∶CA∶La∶Ni = 2∶2∶1∶1. The mixture was heated to 40 °C and vigorously stirred for 1 h. The temperature was then raised to 80 °C and maintained until the water was completely evaporated. The resulting gel was dried overnight in an oven at 80 °C. The dried gel was subsequently transferred to a muffle furnace and calcined at 200 °C for 1 h (heating rate: 5 °C/min), followed by further calcination at 650 °C for 2 h at the same heating rate.
LaCeNiO4 was synthesized as follows. 0.3680 g of La(NO3)3·6H2O, 0.2477 g of Ni(NO3)2·6H2O and 0.3698 g of Ce(NO3)3·6H2O were dissolved in 40 mL of deionized water. Then, 0.98 g of CA was added in a 2∶1 molar ratio relative to the sum of metal cations. The solution was stirred and dried following the same procedure as described for LaNiO3. The resulting gel was dried and then calcined in a muffle furnace: first at 200 °C for 1 h (heating rate 5 °C/min) and subsequently at 800 °C for 4 h using the same heating rate.
CeO2 was synthesized as follows. A predetermined amount of Ce(NO3)3·6H2O was placed in a crucible and transferred to a muffle furnace. The sample was then calcined at 450 °C for 2 h with a heating rate of 5 °C/min.
LaNiO3/CeO2 was synthesized via the following steps. The LaNiO3 precursor solution was prepared as described above. Afterward, 0.5 g of CeO2 was dispersed in 10 mL of deionized water via ultrasonication for a period of time. The LaNiO3 precursor solution was then poured into this suspension. After stirring for 1 h, the mixture was evaporated to dryness at 80 °C to obtain a gel uniformly distributed over the CeO2 support. The subsequent steps were identical to those used for the preparation of LaNiO3.
Ni/CeO2 was synthesized as follows. 0.1580 g of Ni(NO3)2·6H2O was dissolved in 40 mL of deionized water. After complete dissolution, 0.5 g of CeO2 was added to the solution. The mixture was stirred at 40 °C for 1 h, then the temperature was raised to 80 °C to evaporate the water to dryness. The obtained solid was dried overnight at 80 °C, followed by calcination at 600 °C for 4 h with a heating rate of 5 °C/min.
Ni-La/CeO2 was synthesized as follows. 0.3680 g of La(NO3)3·6H2O and 0.2477 g of Ni(NO3)2·6H2O were dissolved in 40 mL of deionized water. Then, 0.5 g of CeO2 was added to the solution, and the mixture was stirred at room temperature for 1 h. The subsequent drying and calcination conditions were identical to those employed in the preparation of LaNiO3.
1.3　Catalytic performance test
The CO2 methanation activity of the catalysts was evaluated using a fixed-bed reactor operated at atmospheric pressure. The reactor tube had an inner diameter of 8 mm and a length of 450 mm. A precisely weighed amount of 0.1 g of catalyst was mixed with 0.2 g of quartz sand and loaded into the catalytic reactor tube. The catalyst bed was packed with a layer of quartz wool at both the top and bottom to secure its position. Subsequently, the reactor was heated to 600 °C under a continuous N2 flow (50 mL/min). Upon reaching this temperature, the gas was switched to a mixture of 80% H2 and 20% N2 flowing at 35 mL/min for catalyst reduction, which lasted for 1 h. After reduction, the gas was switched back to N2 and the reactor was cooled to the desired reaction temperature (200–300 °C). The reaction was then initiated by introducing the feed gas mixture (H2/CO2/N2 = 72∶18∶10) at a gas hourly space velocity (GHSV) of 20000 mL/(g·h). The reaction products were analyzed online at 15 min intervals using a Fuli F80 gas chromatograph equipped with a thermal conductivity detector (GC-TCD). Ar served as the carrier gas and N2 was used as the internal standard. The volumetric percentages and flow rates of each component in the feed and outlet gases were determined by applying the internal standard method. To ensure data reliability, the test results for each catalyst were verified through repeated experiments. In each run, after the reactor reached the set temperature and the feed gas was introduced, the system was allowed to stabilize for 3 h. The average value calculated from multiple data points collected during this stable period was taken as the final test result. The performance of the catalysts was evaluated based on CO2 conversion (%), CH4 selectivity $ {{s}}_{{{\text{CH}}_{\text{4}}}} $ (%), CH4 yield $ {{y}}_{{{\text{CH}}_{\text{4}}}} $(%), CO selectivity sCO (%) and CO yield yCO (%).
$ {{x}}_{{{\text{CO}}_{\text{2}}}}=\frac{{{{{F}}_{{{\mathrm{CO}}_2}}}}_{\text{in}}{-}{{{{F}}_{{{\mathrm{CO}}_2}}}}_{\text{out}}}{{{{{F}}_{{{\mathrm{CO}}_2}}}}_{\text{in}}}{\times 100\%} $
$ {{s}}_{{{\text{CH}}_{\text{4}}}}=\frac{{{{{F}}_{{{\mathrm{CH}}_4}}}}_{\text{out}}}{{{{{F}}_{{{\mathrm{CH}}_4}}}}_{\text{out}}+{{F}}_{{{\text{CO}}_{\text{out}}}}}{\times 100\%} $
$ {{s}}_{\text{CO}}=\frac{{{F}}_{{{\text{CO}}_{\text{out}}}}}{{{{{F}}_{{{\mathrm{CH}}_4}}}}_{\text{out}}+{{F}}_{{{\text{CO}}_{\text{out}}}}}{\times 100\%} $
$ {{y}}_{{{\text{CH}}_{\text{4}}}}={{x}}_{{{\text{CO}}_{\text{2}}}}{\times }{{s}}_{{{\text{CH}}_{\text{4}}}} $
$ {{y}}_{\text{CO}}={{x}}_{{{\text{CO}}_{\text{2}}}}{\times }{{s}}_{\text{CO}} $
where F denotes the gas flow rate of the feed gas and outlet gas, with the unit of mL/min.
1.4　Catalyst characterization
X-ray powder diffraction (XRD) patterns were collected on a Bruker D8 Advance X-ray diffractometer with Cu Kα radiation (λ = 0.15406 nm), between 5°–90° at a scanning speed of 5(°)/min.
H2 temperature programmed reduction (H2-TPR) was conducted on an AutoChemll 2920 chemisorption instrument. 60 mg of the catalyst (40–60 mesh) was loaded into a quartz tube and held in place with quartz wool plugs at both ends. The sample was purged with N2 at 200 °C for 30 min and then cooled to room temperature under a N2 flow before the test. The analysis was performed using a 10% H2/Ar mixture at a flow rate of 30 mL/min. The temperature was ramped from room temperature to 700 °C at a rate of 10 °C/min and held at 700 °C for 2 min.
CO2 temperature programmed desorption (CO2-TPD) was conducted on an AutoChemll 2920 chemisorption instrument. The catalyst was first reduced in H2 at a specified temperature for 1 h. The sample was swept with He (40 mL/min) while heating to 300 °C at 10 °C/min and holding for 1 h after reduction. Subsequently, the temperature was lowered to 50 °C. CO2 was introduced and adsorbed for 1 h when the baseline stabilized. Physically adsorbed CO2 was then removed by sweeping with He (40 mL/min) at 50 °C for 30 min. The desorption step was carried out under a He flow (50 mL/min) by heating from 50 to 800 °C at a rate of 10 °C/min. The desorbed CO2 was monitored using a TCD, and the amount of CO2 desorbed was quantified by calibration with a standard reference.
X-ray photoelectron spectroscopy (XPS) was conducted on a Thermo escalab 250Xi spectrometer equipped with a monochromatized Al Kα X-ray source (hv = 1486.6 eV). All reduced samples were stored in sealed containers at room temperature to prevent oxidation before the test. All spectra were corrected by referring the binding energy of the C 1s neutral carbon peak at 284.8 eV to determine the binding energies.
The field emission transmission electron microscopy (TEM) and energy dispersive X-ray spectroscopy (EDX) analyses were performed on a JEOL JEM-F200 microscope operated at an accelerating voltage of 200 kV. The particle sizes of randomly selected NiO particles were measured using ImageJ software based on the TEM images.
Raman spectroscopy was performed on a Horiba Scientific LabRAM HR Evolution high-resolution spectrometer equipped with a 523 nm semiconductor laser excitation source.
2　Results and discussion
Less
2.1　Phase composition and structure of the catalysts
The XRD patterns of the fresh LaNiO3/CeO2, LaNiO3, LaCeNiO4, Ni/CeO2 and La-Ni/CeO2 are presented in Figure 1(a). The XRD pattern of LaNiO3/CeO2 exhibited characteristic diffraction peaks corresponding to both LaNiO3 (PDF#34-1028, 2θ = 23.1°, 32.8°, 41.3°, 47.4°, 58.6°, 68.8° and 79.0°) and CeO2 (PDF#34-0394, 2θ = 28.5°, 33.0°, 47.4°, 56.3°, 59.0°, 69.4°, 76.7° and 88.4°). This confirmed the successful formation of the LaNiO3 perovskite structure supported on CeO2. LaCeNiO4 belongs to a layered perovskite structure variant derived from La2NiO4, where La3+ is partially substituted by Ce3+. The difference in ionic radii between La3+ (1.03 Å) and Ce3+ (1.01 Å) induced lattice distortion and changes in interplanar spacing upon Ce incorporation[14−15]. The main diffraction peaks observed for LaCeNiO4 corresponded to La2O3 (PDF#71-5408) and NiO (PDF#47-1049), which showed a marked difference from the diffraction patterns of LaNiO3/CeO2. This indicated that LaCeNiO4 was not formed during the preparation of LaNiO3/CeO2. This is because LaNiO3 (ABO3) and LaCeNiO4 (A2BO4) belong to distinct crystal structures and follow different synthesis pathways. Research has shown that the formation of the LaCeNiO4 phase generally required precise Ce doping and higher calcination temperatures, whereas the preparation conditions of LaNiO3/CeO2 (with CeO2 serving as a pre-synthesized support and calcination at 650 °C) tended to favor the formation of the two phases (LaNiO3 and CeO2)[15]. The XRD pattern of Ni/CeO2 exhibited sharp diffraction peaks of CeO2 alongside distinct NiO peaks at 2θ = 37.2°, 43.2°, 62.8°, 75.3° and 79.3°. The XRD pattern of La-Ni/CeO2 showed no characteristic peaks for LaNiO3 or La2O3. Only diffraction peaks of CeO2 and NiO were observed, indicating that Ni existed in the form of NiO. These results suggested that the formation of LaNiO3 required the assistance of citric acid and ethylene glycol. The carboxyl groups (−COOH) of citric acid formed stable complexes with La3+ and Ni2+ ions, ensuring the homogeneous distribution of La and Ni. Meanwhile, the hydroxyl groups (−OH) of ethylene glycol underwent an esterification reaction with the carboxyl groups of citric acid to link the metal ions to the citrate complexes, thereby guaranteeing uniform mixing of the metal ions and the formation of a stable structure[16].
The XRD patterns of the reduced samples are presented in Figure 1(b) (reduction conditions: 600 °C, 80% H2/20% N2, 1 h). After reduction, the diffraction peaks of LaNiO3 in LaNiO3/CeO2 disappeared, with the formation of La2O3 (2θ = 26.1°, 27.7°, 39.4° and 46.0°), NiO and Ni0 (PDF#04-0850, 2θ = 44.5° and 51.7°). After reduction of LaCeNiO4, diffraction peaks corresponding to La2O3 and Ni0 were observed. After reduction, the XRD pattern of the Ni/CeO2 catalyst still showed diffraction peaks of CeO2 and NiO, with partial reduction of NiO to Ni0. Similarly, reduction of La-Ni/CeO2 led to the formation of Ni0, and the diffraction peaks of La2O3 were also observed.
The average crystallite sizes of NiO and Ni0 were calculated using the Debye-Scherrer equation, with the results presented in Table 1. The size relationship between NiO and Ni0 particles remained consistent in both the fresh and reduced samples. The Ni0 particle size of La-Ni/CeO2 was significantly smaller than that of Ni/CeO2 (15.2 vs. 35.1 nm). Similarly, the reduced LaNiO3 perovskite displayed smaller Ni0 particles (13.9 nm). The Ni0 particle size was further reduced to 12.6 nm in LaNiO3/CeO2. These results demonstrated that the LaNiO3 perovskite structure, the interaction between La and Ni, and the interaction between the active phase and the CeO2 support were key factors promoting the dispersion of Ni species.
The synergistic effect of the aforementioned factors further endowed LaNiO3/CeO2 with smaller-sized and highly dispersed Ni0 particles. The TEM image of LaNiO3/CeO2 (Figure 2) further confirmed that the NiO particles possessed structural features of small size and high dispersion. The particle size distribution was concentrated in the range of 5–12 nm, with an average diameter of 8.55 nm. Meanwhile, EDX mapping revealed a homogeneous distribution of Ni, La and Ce elements across the catalyst region.
2.2　Reduction behavior of active species and distribution of surface basic sites
The reduction behavior of active species in the fresh catalysts was characterized by H2-TPR. The reduction profiles and the corresponding hydrogen consumptions are shown in Figure 3(a) and Table 2, respectively. Both LaNiO3 and LaNiO3/CeO2 exhibited two reduction peaks in their H2-TPR profiles. The low-temperature reduction peak at 350–400 °C was attributed to the destruction of the perovskite structure, where Ni3+ was reduced to Ni2+. The high-temperature reduction peak at 450–550 °C was ascribed to the reduction of Ni2+ to Ni0[17−18]. La-Ni/CeO2 exhibited a prominent reduction peak in the range of 300–350 °C, which may be attributed to the predominant presence of Ni in the form of NiO rather than in a perovskite structure with La. The reduction peak is attributed to the direct reduction of Ni2+ to Ni0. The reduction peaks of Ni/CeO2 at 280–310 and 310–340 °C were attributed to the reduction of oxygen species in the Ni–Ce–O solid solution. This solid solution was formed by the incorporation of Ni2+ into the CeO2 lattice, which generated oxygen vacancies and created easily reducible oxygen species[19]. The reduction peak at 360–390 °C corresponded to the reduction of well-dispersed NiO species that exhibited strong interaction with the CeO2 support[20].
LaCeNiO4 exhibited a broad reduction peak in the range of 300–450 °C. The peak at 300–400 °C was ascribed to the reduction of surface NiO species, while the peak at 400–450 °C corresponded to the reduction of NiO species weakly interacting with the support[21−22].
The surface basic sites of the fresh catalysts were determined by CO2-TPD (Figure 3(b)), and the amount of CO2 desorbed is presented in Table 3. The CO2 adsorption capacity of the catalyst at low temperatures is directly governed by the strength and population of its surface basic sites, which furthermore play distinct roles in the reaction[23−24]. CO2 desorption peaks at 50–200 °C correspond to weak basic sites, which originate primarily from surface hydroxyl groups. Peaks at 200–400 °C are assigned to medium basic sites, whereas desorption peaks above 400 °C are attributed to strong basic sites, namely Lewis basic sites associated with anions[25]. Weak and moderate basic sites improve CO2 methanation performance, whereas strong basic sites show no promotional effect and can even suppress the hydrogenation reaction[26]. LaNiO3, LaNiO3/CeO2 and La-Ni/CeO2 consisted of weak, moderate and strong basic sites; LaCeNiO4 contained weak and moderate sites, and Ni/CeO2 was composed of weak and strong basic sites. CO2-TPD quantification revealed that LaNiO3/CeO2 exhibited considerably larger CO2 uptake on its weak, moderate, and strong basic sites compared to LaNiO3, while La-Ni/CeO2 also showed higher adsorption on its weak and moderate sites relative to LaCeNiO4. This improvement was largely because the CeO2 support played a key role in enhancing the catalyst basicity[27]. The higher CO2 uptake observed on the weak and moderate basic sites of LaNiO3/CeO2 relative to La-Ni/CeO2 further confirmed that the perovskite structure contributes to an improved basic property of the catalyst. Basic sites facilitated the adsorption and activation of CO2 at low and medium temperatures and are thus critical to improving catalytic activity[28]. In contrast, Ni/CeO2 showed inferior activity owing to its lack of weak and moderate basic sites and the resulting low CO2 adsorption capacity. Nevertheless, the strength of basic sites on the catalyst did not exhibit a linear correlation with its catalytic performance. A comprehensive analysis that also considered properties such as oxygen vacancy concentration and dispersion of active sites was required to evaluate the catalytic activity, as discussed in Section 2.4.
2.3　Surface chemistry and oxygen defect density of the catalysts
The five catalysts were characterized by XPS, focusing on the Ni, La and Ce elements for surface composition and chemical state analysis. As shown in Figure 4(a), all four catalysts (LaNiO3/CeO2, LaNiO3, LaCeNiO4 and La-Ni/CeO2) contained both La and Ni elements. However, the peaks of Ni 2p3/2 and La 3d3/2 overlapped, thus resulting in multiple split peaks. Two peaks with binding energies in the range of 848–850 and 855–857 eV corresponded to La 3d3/2[29]. The peaks located at 850–852 and 853–855 eV were assigned to Ni2+ in NiO and Ni3+ in LaNiO3, respectively, while the satellite peak appearing at about 864 eV confirmed the coexistence of mixed Ni2+/Ni3+ valence states in the fresh catalysts. The binding energies of the corresponding peaks showed slight shifts, and their intensities varied across different catalysts. These differences could be attributed to variations in Ni dispersion and the metal-support interactions among Ni, La and Ce[30]. Ni2+ peaks (854 eV) and Ni satellite peaks (860 eV) could be observed in the Ni 2p XPS spectrum of the Ni/CeO2[31].
Figure 4(b) shows the La 3d5/2 XPS spectra of the four catalysts. All four La-containing catalysts exhibited characteristic doublet peaks at approximately 835 and 837 eV binding energies, which were close to those of La2O3, indicating that La existed as stable La3+ in the four catalysts[32]. Previous studies have indicated that La2O3 as a promoter can suppress the aggregation of Ni particles[33]. This was corroborated by comparing the Ni particle sizes of Ni/CeO2 with those of the other four catalysts (Table 1), clearly indicating that La2O3 effectively reduces the Ni particle size and improves its dispersion.
Figure 4(c) shows the Ce 3d spectra for all cerium-containing catalysts. The key advantage of CeO2 lies in its ability to undergo reversible conversion between Ce4+ and Ce3+. This process is accompanied by the generation of oxygen vacancies. A higher proportion of Ce3+ indicates a greater concentration of oxygen vacancies in the catalysts[34]. The ratios of Ce3+/(Ce3++Ce4+) for the four catalysts are listed in Table 1.
The Raman spectra of the Ni/CeO2, La-Ni/CeO2, LaNiO3/CeO2 and LaCeNiO4 are shown in Figure 4(d). All CeO2-containing catalysts exhibited two vibrational bands at approximately 455 and 590 cm−1, which were assigned to the F2g and defect-induced mode (D) of the cubic ceria fluoride phase, respectively[35−36]. Oxygen vacancy concentrations in the CeO2 phase could also be evaluated by the intensity ratio ID/IF2g, with a higher ratio indicating more abundant vacancies[37−38]. The trend was consistent with the Ce3+/(Ce3++Ce4+) ratio derived from XPS.
Ni/CeO2 showed the lowest conversion in the activity tests (Section 2.4), which was attributed to its limited oxygen vacancies and poor CO2 activation ability. The electronic interaction between the LaNiO3 perovskite and the CeO2 support in LaNiO3/CeO2 facilitated the reduction of Ce4+ to Ce3+, thereby increasing the number of oxygen vacancies (Ce3+/(Ce3++Ce4+) = 9.2%). This high oxygen vacancy concentration enabled efficient adsorption and activation of CO2 even at low temperatures (Section 2.4). Notably, catalytic performance was maximized only when oxygen vacancies worked in synergy with properly tuned active sites. This was exactly confirmed by LaCeNiO4. Despite having the highest oxygen vacancy concentration, its conversion at 300 °C (16.5%) was lower than that of LaNiO3/CeO2 (Section 2.4). This inferior activity might be due to the low basicity (Table 3) and the lack of effective metal-support interaction in its perovskite-variant structure, which consequently failed to optimally regulate the dispersion and particle size of Ni0 active sites (Table 1).
2.4　Catalytic performance
The catalytic performance of the catalysts was investigated in the temperature range of 200–300 °C, as shown in Figure 5. A consistent increasing trend in CO2 conversion was observed for each catalyst with increasing temperature. Ni/CeO2 exhibited the lowest catalytic performance. The CO2 conversion increased gradually from 3.4% at 200 °C to 8.6% at 300 °C, while the CH4 selectivity remained around 80% within 200–275 °C and increased to 84% at 300 °C. The doping of La improved the catalytic performance. For the La-Ni/CeO2 catalyst, the CO2 conversion increased progressively from 5.7% at 200 °C to 15.1% at 300 °C, while the CH4 selectivity increased gradually from 87% at 200 °C to 91% at 300 °C. In contrast, the perovskite structure showed improved catalytic performance. For LaNiO3, the CO2 conversion increased gradually from 10.4% at 200 °C to 14.7% at 300 °C, while the CH4 selectivity increased significantly from 200 to 275 °C and then stabilized at around 98% after 275 °C. LaCeNiO4 exhibited a CO2 conversion of 7.0% at 200 °C that increased progressively to 16.5% at 300 °C, with CH4 selectivity consistently exceeding 98%. By combining the advantages of the perovskite structure and the CeO2 support, LaNiO3/CeO2 exhibited significantly superior catalytic activity compared to the other four catalysts. Its CO2 conversion increased progressively from 12.0% at 200 °C to 23.6% at 300 °C, while the CH4 selectivity remained consistently close to 100%.
Based on the combined physicochemical characterization and catalytic activity evaluation results presented above, the mechanism of low-temperature CO2 methanation over LaNiO3/CeO2 is schematically summarized in Figure 6.
First, the perovskite structure promoted the dispersion of active phase. As a promoter, La optimized the dispersion of Ni species in the catalyst while preventing the agglomeration of Ni0 particles. This effect was directly evidenced by the Ni0 crystallite sizes obtained from XRD (Table 1 and Figure 2), where LaNiO3 and La-Ni/CeO2 showed much smaller Ni0 particles than the La-free Ni/CeO2. La played a key role in improving the dispersion of Ni species[33], which consequently enabled La-Ni/CeO2 to exhibit significantly higher CO2 conversion and CH4 selectivity than Ni/CeO2. XRD characterization further revealed that the perovskite structure could generate more dispersed Ni0 particles after reduction, whereas La-Ni/CeO2 showed poorer Ni dispersion because of the absence of the perovskite architecture. Therefore, LaNiO3/CeO2 achieved markedly higher CO2 conversion and CH4 selectivity than La-Ni/CeO2, demonstrating that the perovskite structure was one of the core factors enabling high-performance, low-temperature CO2 methanation.
Second, the type and population of basic sites on the catalyst were critical factors for CO2 adsorption. The CO2-TPD results (Table 3) showed that Ni/CeO2 contained a comparatively large number of strong basic sites, owing to the lack of La modification and the absence of perovskite structure regulation. In contrast, LaCeNiO4 mainly exhibited medium basic sites, which was attributed to the lattice distortion caused by Ce substitution. However, the desorption capacities of weak and medium basic sites over LaNiO3/CeO2 were significantly higher than those of the other catalysts. The CeO2 support and perovskite structure synergistically optimize the distribution of basic sites[39], which was crucial for the efficient activation of CO2 over LaNiO3/CeO2 at low temperatures.
Third, the oxygen vacancies in CeO2 promoted CO2 activation. Compared with the unsupported LaNiO3, LaNiO3/CeO2 consistently exhibited higher CO2 conversion, and its CH4 selectivity remained close to 100%. In contrast, the CH4 selectivity of LaNiO3 was only 83.5% at 200 °C and stabilized at 98% by 275 °C. These results indicated that the oxygen vacancies provided by the CeO2 support played a crucial role in enhancing the low-temperature methanation performance.
Finally, the interaction between the active phase and the support could further improve the performance of CO2 methanation. A comparison between LaCeNiO4 and LaNiO3/CeO2 showed that LaNiO3/CeO2 achieved a substantially higher CO2 conversion. Although Raman and XPS results indicated that the Ce3+/(Ce3++Ce4+) ratio of LaCeNiO4 (9.9%) was higher than that of LaNiO3/CeO2 (9.2%), LaCeNiO4 exhibited a much weaker metal-support interaction. This demonstrated that when CeO2 served as a support, it not only optimized the dispersion of Ni species but also, through interaction with Ni, promoted the reduction of Ce4+ and increased the oxygen vacancy concentration[40]. In contrast, LaCeNiO4 involved Ce substituting La sites, which only modified the perovskite lattice structure. These results confirmed that the active phase-support interaction was the key factor for enhancing catalytic performance.
3　Conclusion
Less
In this study, the LaNiO3/CeO2 catalyst was prepared via a perovskite structure pre-structuration and in situ reduction strategy. Its low-temperature CO2 methanation performance was investigated, and the underlying reaction mechanism was systematically explored by combining multiple characterizations, including XRD, TEM, XPS, H2-TPR, CO2-TPD and Raman spectroscopy. The main conclusions are as follows.
LaNiO3/CeO2 exhibited excellent catalytic activity at low temperatures, with CH4 selectivity consistently approaching 100% and CO2 conversion reaching 23.6% at 300 °C. After reduction, the LaNiO3 perovskite yielded small-sized and highly dispersed Ni0 particles (average particle size: 12.6 nm), which provided abundant active sites for the reaction. The CeO2 support not only significantly increased the number of basic sites on the catalyst surface, but also promoted the activation of CO2 through its high concentration of oxygen vacancies (Ce3+/(Ce3++Ce4+) = 9.2%, ID/IF2g = 0.35). The interactions among the active Ni species, La species and the CeO2 support further enhanced the catalytic activity and additionally facilitated the generation of oxygen vacancies in CeO2. The synergy of the above effects endowed the LaNiO3/CeO2 catalyst with outstanding performance for low-temperature CO2 methanation. By systematically studying the physicochemical properties and catalytic activity of LaNiO3/CeO2, this work provides a theoretical reference for the design and optimization of efficient catalysts for low-temperature CO2 methanation.
References
Less
1
QUILCAILLE Y, GUDMUNDSSON L, SCHUMACHER D L, et al. Systematic attribution of heatwaves to the emissions of carbon majors[J]. Nature, 2025, 645(8080): 392−398.
2
LIU H, YU Z, HUANG W, et al. Effect of Ce modification on the performance of CuLDH catalyst for CO2 hydrogenation to methanol[J]. J Fuel Chem Technol, 2024, 52(2): 159−170.
3
GUO Z-L, BIAN X-L, DU Y-B, et al. Recent advances in integrated carbon dioxide capture and methanation technology[J]. J Fuel Chem Technol, 2023, 51(3): 293−302.
4
EVERETT O E, ZONETTI P C, ALVES O C, et al. The role of oxygen vacancies in the CO2 methanation employing Ni/ZrO2 doped with Ca[J]. Int J Hydrogen Energy, 2020, 45(11): 6352−6359.
5
BACARIZA M C, GRAçA I, BEBIANO S S, et al. Magnesium as promoter of CO2 methanation on Ni-based USY zeolites[J]. Energy Fuels, 2017, 31(9): 9776−9789.
6
SHANG X, DENG D, WANG X, et al. Enhanced low-temperature activity for CO2 methanation over Ru doped the Ni/CexZr1−xO2 catalysts prepared by one-pot hydrolysis method[J]. Int J Hydrogen Energ, 2018, 43(14): 7179−7189.
7
ZHANG L, BIAN L, ZHU Z, et al. La-promoted Ni/Mg-Al catalysts with highly enhanced low-temperature CO2 methanation performance[J]. Int J Hydrogen Energy, 2018, 43(4): 2197−2206.
8
GARBARINO G, WANG C, CAVATTONI T, et al. A study of Ni/La-Al2O3 catalysts: A competitive system for CO2 methanation[J]. Appl Catal B: Environ, 2019, 248: 286−297.
9
ONRUBIA-CALVO J A, BERMEJO-LÓPEZ A, PÉREZ-VÁZQUEZ S, et al. Applicability of LaNiO3-derived catalysts as dual function materials for CO2 capture and in-situ conversion to methane[J]. Fuel, 2022, 320: 123842.
10
ALKHOORI A A, KOMARALA E P, DABBAWALA A A, et al. Exsolved LaNiRuO3 perovskite-based catalysts for CO2 methanation reaction[J]. RSC Sustainable, 2024, 2(12): 3866−3878.
11
LIU K, XU X, XU J, et al. The distributions of alkaline earth metal oxides and their promotional effects on Ni/CeO2 for CO2 methanation[J]. J CO2 Util, 2020, 38: 113−124.
12
GUAN X, WANG X, ZHANG X, et al. Boosting CO2 fixation into dimethyl carbonate via multiple active sites constituted by VO-Ce-O vacancy clusters on single-unit-cell CeO2 nano-sheets[J]. Angew Chem Int Ed, 2025, 64(33): e202423958.
13
ONRUBIA-CALVO J A, PEREDA-AYO B, GONZáLEZ-MARCOS J A, et al. Design of CeO2-supported LaNiO3 perovskites as precursors of highly active catalysts for CO2 methanation[J]. Catal Sci Technol, 2021, 11(18): 6065−6079.
14
HANG Y, KRYLOV D, ROSENKRANZ M, et al. Magnetic anisotropy of endohedral lanthanide ions: Paramagnetic NMR study of MSc2N@C80-Ih with M running through the whole 4f row[J]. Chem Sci, 2015, 6(4): 2328−2341.
15
REN J, MEBRAHTU C, VAN KOPPEN L, et al. Enhanced CO2 methanation activity over La2−xCexNiO4 perovskite-derived catalysts: Understanding the structure-performance relationships[J]. Chem Eng J, 2021, 426: 131760.
16
ZHU T, WANG M, YUAN B, et al. Research progress in methane combustion catalyzed by perovskite catalysts[J]. Clean Coal Technol, 2025, 31(2): 63−79.
17
LI J, LIU G, WANG J, et al. Ni-Co and Ni-Cu bimetallic alloy catalysts for CO methanation[J]. J Fuel Chem Technol, 2020, 48(5): 610−618.
18
LUO Y, WANG X, QIAN Q, et al. Studies on B sites in Fe-doped LaNiO3 perovskite for SCR of NOx with H2[J]. Int J Hydrogen Energ, 2014, 39(28): 15836−15843.
19
YE R-P, LI Q, GONG W, et al. High-performance of nanostructured Ni/CeO2 catalyst on CO2 methanation[J]. Appl Catal B: Environ, 2020, 268: 118474.
20
TANG K, LIU W, LI J, et al. The effect of exposed facets of ceria to the nickel species in nickel-ceria catalysts and their performance in a NO + CO reaction[J]. ACS Appl Mater Interfaces, 2015, 7(48): 26839−26849.
21
MEBRAHTU C, PERATHONER S, GIORGIANNI G, et al. Deactivation mechanism of hydrotalcite-derived Ni–AlOx catalysts during low-temperature CO2 methanation via Ni-hydroxide formation and the role of Fe in limiting this effect[J]. Catal Sci Technol, 2019, 9(15): 4023−4035.
22
ANG M L, OEMAR U, SAW E T, et al. Highly active Ni/xNa/CeO2 catalyst for the water–gas shift reaction: Effect of sodium on methane suppression[J]. ACS Catal, 2014, 4(9): 3237−3248.
23
ANG Y, BAN H, WANG Y, et al. Unraveling the role of basic sites in the hydrogenation of CO2 to formic acid over Ni-based catalysts[J]. J Catal, 2024, 430: 115357.
24
LIU J, BING W, XUE X, et al. Alkaline-assisted Ni nanocatalysts with largely enhanced low-temperature activity toward CO2 methanation[J]. Catal Sci Technol, 2016, 6(11): 3976−3983.
25
YIN L, CHEN X, SUN M, et al. Insight into the role of Fe on catalytic performance over the hydrotalcite-derived Ni-based catalysts for CO2 methanation reaction[J]. Int J Hydrogen Energy, 2022, 47(11): 7139−7149.
26
LIU Y, LI D, ZHAO H, et al. Boosting CO2 methanation activity by tuning Ni crystal plane and oxygen vacancy in Ni/CeO2 catalyst[J]. Chem Eng J, 2024, 494: 153004.
27
GAO P, TANG S, HAN X, et al. Boosting CO2 methanation via tuning metal-support interaction over hollow Ni/CeO2[J]. Chem Eng J, 2024, 498: 155784.
28
DEWANGAN N, HUI W M, JAYAPRAKASH S, et al. Recent progress on layered double hydroxide (LDH) derived metal-based catalysts for CO2 conversion to valuable chemicals[J]. Catal Today, 2020, 356: 490−513.
29
MICKEVIČIUS S, GREBINSKIJ S, BONDARENKA V, et al. Investigation of epitaxial LaNiO3−x thin films by high-energy XPS[J]. J Alloy and Compd, 2006, 423(1): 107−111.
30
MEBRAHTU C, ABATE S, CHEN S, et al. Enhanced catalytic activity of iron-promoted nickel on γ-Al2O3 nanosheets for carbon dioxide methanation[J]. Energy Technol, 2018, 6(6): 1196−1207.
31
ZHENG H, LIAO W, DING J, et al. Unveiling the key factors in determining the activity and selectivity of CO2 hydrogenation over Ni/CeO2 catalysts[J]. ACS Catal, 2022, 12(24): 15451−15462.
32
SANIVARAPU S R, LAWRENCE J B, SREEDHAR G. Role of surface oxygen vacancies and lanthanide contraction phenomenon of Ln(OH)3 (Ln = La, Pr, and Nd) in sulfide-mediated photoelectrochemical water splitting[J]. ACS Omega, 2018, 3(6): 6267−6278.
33
QUINDIMIL A, DE-LA-TORRE U, PEREDA-AYO B, et al. Ni catalysts with La as promoter supported over Y- and BETA- zeolites for CO2 methanation[J]. Appl Catal B: Environ, 2018, 238: 393−403.
34
NING J, DONG C, LI M, et al. Dispersion of copper oxide species on nanostructured ceria[J]. J Chem Phys, 2020, 152(9): 094708.
35
WEBER W H, HASS K C, MCBRIDE J R. Raman study of CeO2: Second-order scattering, lattice dynamics, and particle-size effects[J]. Phys Rev B, 1993, 48(1): 178−185.
36
WU Z, LI M, HOWE J, et al. Probing defect sites on CeO2 nanocrystals with well-defined surface planes by Raman spectroscopy and O2 adsorption[J]. Langmuir, 2010, 26(21): 16595−16606.
37
GAO Y, ZHANG Z, LI Z, et al. Understanding morphology-dependent CuOx-CeO2 interactions from the very beginning[J]. Chin J Catal, 2020, 41(6): 1006−1016.
38
WEN Y, HUANG Q, ZHANG Z, et al. Morphology-dependent catalysis of CeO2-based nanocrystal model catalysts[J]. Chin J Chem, 2022, 40(15): 1856−1866.
39
ZHANG T, WANG W, GU F, et al. Enhancing the low-temperature CO2 methanation over Ni/La-CeO2 catalyst: The effects of surface oxygen vacancy and basic site on the catalytic performance[J]. Appl Catal B: Environ, 2022, 312: 121385.
40
XIE J-X, ZHAO Y-P, LI Q, et al. Catalytic conversion of lignin and lignin-derived β-O-4 ether to cyclohexanols over a CeO2-doped carbon-supported nickel-based catalyst[J]. ACS Sustainable Chem Eng, 2024, 12(2): 904−915.
Appendix
Less
Year 2026 volume 54 Issue 8
PDF
168
77
Cite this Article
BibTeX
Article Info
doi: 10.1016/S1872-5813(26)60662-7
  • Receive Date：2025-10-29
  • Online Date：2026-09-23
  • Published：2026-08-10
Article Data
Affiliations
History
  • Received：2025-10-29
  • Revised：2025-12-09
  • Accepted：2025-12-30
Affiliations
    1National Engineering Research Center of New Energy Power Generation, North China Electric Power University, Beijing 102206, China
    2PowerChina Northwest Engineering Corporation Limited, Xi’an 710065, China

Corresponding:

References
Share
https://castjournals.cast.org.cn/joweb/rlhxxb/EN/10.1016/S1872-5813(26)60662-7
Share to
QR

Scan QR to access full text

Cite this article
BibTeX
Citations
表12种不同金属材料的力学参数
科
Family		 属数
Number of
genus		 种数
Number of
species		 占总种数比例
Percentage of
total species (%)		 属
Genus		 种数
Number of
species		 占总种数比例
Percentage of total
species (%)
鹅膏菌科Amanitaceae 2 11 5.26 鹅膏菌属 Amanita 10 4.78
小菇科 Mycenaceae 2 12 5.74 丝盖伞属 Inocybe 5 2.39
多孔菌科 Polyporaceae 8 14 6.70 蜡蘑属 Laccaria 5 2.39
红菇科 Russulaceae 3 23 11.00 小皮伞属 Marasmius 6 2.87
小菇属 Mycena 11 5.26
光柄菇属 Pluteus 5 2.39
红菇属 Russula 17 8.13
栓菌属 Trametes 5 2.39
关闭全屏
  • BibTeX
  • EndNote
  • RefWorks
  • TxT
Links
Articles
Latest Articles
Most Read
Collections
Updates
Events
News
Multimedia
About
About Us
Contact
No. 86 Xueyuan South Road, Haidian District, Beijing
100081
010-62662699(Operation and Technical Support)
qkjq@cast.org.cn

Copyright © 2025 China Association for Science and Technology. All rights reserved. For all open access content, the relevant licensing terms apply.
Sponsored by the Office of the Leading Group for Cybersecurity and Informatization of CAST, and supported by Science and Technology Review Publishing House