The coupling reactions of methanol and long-chain alkanes (n-dodecane, n-tetradecane and n-hexadecane) over CHA-type molecular sieves were studied in a fixed bed reactor. Over SAPO-34 and SSZ-13, it was found that the induction period of methanol conversion was shortened by the introduction of long-chain alkanes. However, the addition of long-chain alkanes had little influence on the product distribution. Polymethylbenzenes and the derivatives were the main retained species on spent SSZ-13 catalyst, while adamantanes were the main retained species on SAPO-34. This indicates that coking species formation was mainly related to the further transformation of long-chain alkane/methanol coupling products at acid sites of the molecular sieve. These findings provide valuable information of long chain alkanes conversion and methanol reaction behavior of induction period over small pore CHA molecular sieves.

It is crucial to develop arsenic removal adsorbents with strong sulfur resistance under middle-low-temperature flue gas conditions (<400 ℃). In this work, five Fe-Ce-La oxides were prepared by co-precipitation method, and FeCeLaO/SiO₂-Al₂O₃ composite adsorbents were prepared by coupling fly ash-based Si-Al carriers. The active components Fe-Ce-La oxides and Si-Al carriers were characterized by TPD, TG, XRF, BET and XPS, respectively. The effects of temperature, Si/Al ratio and FeCeLaO loading rate on the sulfur resistance were investigated. Results show that the SO₂ promotes the arsenic removal of Fe₂O₃, CeLaO and FeCeLaO. At 400 ℃, the arsenic removal efficiencies of the three oxides increase from 45.3%, 72.5% and 81.3% without SO₂ to 62.6%, 80.5% and 91.0%, respectively. The SO₂ inhibits the arsenic removal of La₂O₂CO₃ and FeLaO, and the inhibition effect is pronounced at high temperatures. The sulfur poisoning resistance of Si-Al carriers increases with the increase of Si/Al ratio. When the Si/Al ratio is increased to 9.74, the arsenic removal efficiency in the SO₂ environment is 13.9% higher than that in the absence of SO₂. Introducing FeCeLaO active components is beneficial for enhancing the SO₂ poisoning resistance of Si-Al carriers. The strong sulfur resistance of the FeCeLaO/SiO₂-Al₂O₃ composite adsorbent results from multiple factors: protective effects of Ce on Fe, La and Al; sulfation-induced generation of Ce³⁺ and surface-adsorbed oxygen; and strong surface acidity of SiO₂.

As one of the most promising new energy sources, hydrogen energy is expected to usher in a full-fledged “hydrogen economy” in the 21st century. Compared with traditional high-pressure gaseous and cryogenic liquid hydrogen storage methods, solid-state chemical hydrogen storage shows significant advantages in safety, high efficiency, and cost-effectiveness. Magnesium-based lightweight hydrogen storage materials have attracted widespread attention due to their high gravimetric hydrogen storage density (7.6%) and favorable reversibility. However, their sluggish reaction kinetics and stringent operating conditions (with H₂ release temperatures exceeding 350 °C and H₂ absorption pressures above 4 MPa) pose major challenges for practical applications. Domestic and international researchers have conducted in-depth studies to address these issues, achieving substantial progress in the modification of magnesium-based hydrogen storage alloys. This paper systematically elaborates on major modification techniques such as alloying, nanostructuring, and catalytic material doping, providing a comprehensive analysis of the strengths and limitations of each approach. Furthermore, it offers prospects for the future development of magnesium-based hydrogen storage materials by integrating current theoretical and experimental research findings.

The adsorptive denitrification performance of MIL-101(Cr)-0.5 toward pyridine, aniline or quinoline in simulated fuels with basic nitrogen content of 1732 μg/g was evaluated separately. Furthermore, the effects of adsorption temperature, adsorption time and adsorbent dosage on their adsorptive denitrification performance were systematically investigated. The experimental results demonstrated that under a fixed adsorbent dosage of 0.05 g and a simulated fuel volume of 10 mL, the optimal removal efficiency for aniline was achieved at 30 ℃ within 30 min, whereas higher temperatures and longer times (40 ℃ and 40 min) were required for effective removal of pyridine and quinoline. Density Functional Theory (DFT) calculations were conducted via Materials Studio (MS) software to study the adsorptive denitrification mechanism of MIL-101(Cr) toward these three basic nitrogen-containing compounds. The simulation calculation results revealed that the interaction between pyridine and MIL-101(Cr) primarily involved coordination adsorption. In contrast, the interaction between aniline or quinoline and MIL-101(Cr) proceeded mainly through coordination, with additional contributions from π-complexation and hydrogen bonding. The overall adsorption strength order is pyridine > aniline > quinoline. During the adsorption process, pyridine and quinoline transfer electrons to the MIL-101(Cr) surface through the H→C→N→Cr³⁺ pathway, while aniline transfers electrons to the MIL-101(Cr) surface through various pathways, including N→Cr³⁺, N→C→Cr³⁺ and N→H→O. Furthermore, adsorption kinetics studies indicated that the adsorption processes for all three basic nitrogen-containing compounds followed the quasi second order kinetic models. The experimental results on the effect of benzene on the adsorptive denitrification performance of MIL-101(Cr)-0.5 demonstrated that benzene exerted a more significant impact on the adsorption of aniline and quinoline. Finally, the adsorbent was regenerated using ethanol washing. It was found that MIL-101(Cr)-0.5 retained stable denitrification performance after two regeneration cycles.

Biomass-based hydrocarbon fuels, as one of the alternatives to traditional fossil fuels, have attracted considerable attention in the energy field due to their renewability and environmental benefits. This article provides a systematic review of recent research progress in the chemical synthesis of biomass-based hydrocarbon fuels. It outlines the conversion pathways using feedstocks such as lipids, terpenoids, cellulose/hemicellulose, and lignin. Depending on the feedstock, various products with distinct structural characteristics can be prepared through reactions such as cyclization, condensation, and catalytic hydrogenation. Throughout the synthesis process, three key factors play a critical role: efficient catalyst development, production process optimization, and computational-chemistry-based molecular design. Finally, the article discusses future perspectives for biomass-based hydrocarbon fuel synthesis research.

Propylene oxide (PO) is an important petrochemical materials used to produce downstream products such as propylene glycol (PG), polyether polyols, and dipropylene glycol (DPG). Among these, DPG is commonly used as a solvent for fragrances, cosmetics, food additives, and detergents, and can also be served as a moisturizer in cosmetics, showing broad application prospects. The distribution of DPG isomers in the products synthesized from PO and PG has a significant impact on the quality of the products. Therefore, conducting thermodynamic calculation on the reaction of PO and PG to synthesize DPG can provide a theoretical basis for practical operations and product distribution regulation. So, in this paper, the thermodynamic parameters of PO, 1,2-PG, H₂O, tripropylene glycol (TPG) and three isomers of DPG under different reaction conditions is calculated. Additionally, the $ {\Delta }_{{\mathrm{r}}}G $, $ {\Delta }_{{\mathrm{r}}}{H}^{} $ and lnK for four potential reactions at various reaction temperatures and pressures are calculated. By designing isodesmic reactions and combining the results of thermodynamic calculations, the $ {\Delta }_{{\mathrm{f}}}{H}^{\text{θ}} $ and $ {\Delta }_{{\mathrm{f}}}{G}^{\text{θ}} $ for the isomers of DPG are obtained, and the relative error is less than 7%. The results show that in the process of preparing DPG by PO and PG, when PO∶PG = 1, the reaction temperature ranges from 298.15 to 413.15 K, and the pressure ranges from 101.325 to 506.625 kPa, the reactions of $ {\mathrm{PO+PG}}\rightleftharpoons {\mathrm{DPG}} $ and $ {\mathrm{PO+DPG}}\rightleftharpoons {\mathrm{TPG}} $ are thermodynamically spontaneous. While the reactions of $ {\mathrm{PG+PG}}\rightleftharpoons {\mathrm{DPG+{H}_{2}O}} $ and $ {\mathrm{PG+DPG}}\rightleftharpoons {\mathrm{TPG+{H}_{2}O}} $ are thermodynamically unspontaneous. The optimal reaction temperature and pressure are 413.15 K and 101.325 kPa. The thermodynamic stability of the three isomers is DPG1>DPG2>DPG3 under standard conditions. The accuracy of the computational results is verified through experimental design, and based on this, the factors affecting product distribution are analyzed.

Oxygen carriers play a fundamental role in chemical looping combustion (CLC). Iron-based carriers have been extensively investigated owing to their abundance and environmentally friendly. However, the reactivity and separability of iron-based carriers require further enhancement. This study investigates the effect of the concentration of Mn doping on reactivity, elastic properties and magnetic properties based on density functional theory (DFT) calculations. Theoretical results demonstrate that Mn doping effectively enhances reactivity by reducing the oxygen vacancy formation energy ($ {{E}}_{\text{vac}} $) from 2.33 to 0.87 eV. However, Mn doping introduces lattice distortions that deteriorate elastic properties, thereby reducing wear resistance, as evidenced by a 54.54% decrease in the hardness-to-Young's modulus ratio ($ {{H}}_{\text{V}}\text{/}{{E}}_{\text{V}} $) for α-Fe₂O₃ and an 83.33% reduction for Fe₃O₄. Furthermore, Mn doping also modifies magnetic properties. The maximum of saturation magnetization ($ {{M}}_{\text{s}} $) of Fe₃O₄ reaches 121.02 emu/g at 33.33% Mn doping concentration. Finally, systematic evaluation identifies 33.33% as the optimal Mn doping concentration, achieving a balance in enhanced reactivity, superior magnetic performance, and retained elastic stability.

To deepen understanding of the evolution of coal char microstructural properties of coal char during the co-pyrolysis of coking coal with additives, this study incorporated two typical additives, coal tar pitch (CTP) and waste plastic (HDPE), into a blended coal sample and carried out pyrolysis experiments. The pyrolysis process and the microstructure of char were systematically characterized using various analytical techniques, including thermogravimetric analysis (TGA), X-ray diffraction (XRD) and Raman spectroscopy. Data correlation analysis was performed to reveal the mechanism of carbon structural ordering evolution within the critical temperature range (350−600 °C) from colloidal layer formation to semi-coke conversion in coking coal, and to elucidate the regulatory effects of different additives on coal pyrolysis pathways. The results indicate that HDPE releases free radicals during high-temperature pyrolysis, accelerating the pyrolysis reaction and increase the yield of volatile components. Conversely, CTP facilitates pyrolysis at low temperatures through its light components, thereby delaying high-temperature reactions due to the colloidal layer’s effect. XRD results indicate that during the process of pyrolysis, there is a progressive decrease in the interlayer spacing of aromatic layers (d₀₀₂), while the aromatic ring stacking height (L_c) and lateral size (L_a) undergo significant of carbon skeleton ordering. Further comparative reveals that CTP partially suppresses structural ordering at low temperatures, whereas HDPE promotes the condensation and alignment of aromatic clusters via a free radical mechanism. Raman spectroscopy reveals a two-stage reorganization mechanism in the microstructure of the coal char: the decrease in the I_D/I_G ratio between 350 and 550 °C is primarily attributed to the cleavage of aliphatic side chains and cross-linking bonds, leading to a reduction in defective structures; whereas the increase in I_D/I_G between 550 and 600 °C is closely associated with enhanced condensation reactions of aromatic structures. Correlation analysis further demonstrates progressive graphitization during pyrolysis, with a significant positive correlation (R² > 0.85) observed between d₀₀₂ and the full width at half maximum of the G-band (FWHM-G).

Aiming at the problems of insufficient activity and selectivity of Cu-based catalysts in CO₂ hydrogenation to methanol, Al₂O₃, ZrO₂ and CeO₂ modified Cu-ZnO catalysts by the co-precipitation method were prepared, and the influence mechanism of additives on the structure-performance relationship of the catalysts was systematically explored. Through a variety of characterization methods such as XRD, N₂ physical adsorption-desorption, TEM, H₂-TPR, CO₂-TPD and XPS, combined with catalytic performance evaluation experiments, the correlation between the microstructure of catalysts and the reaction performance of CO₂ hydrogenation to methanol was analyzed in depth. The results show that metal additives significantly improve the performance of catalysts. After the introduction of additives, the specific surface area and pore volume of the catalysts increase, the grain size of Cu decreases, and its dispersion improves. The Ce-modified CZC catalyst exhibited the best performance, with the grain size of CuO as small as 11.41 nm, and the surface oxygen vacancy concentration (O_Ⅱ/O_Ⅰ = 3.15) was significantly higher than that of other samples. The reaction performance test shows that under the conditions of 2.8 MPa, 8000 h⁻¹ and 280 °C, the CO₂ conversion of the CZC catalyst reached 18.83%, the methanol selectivity was 68.40%, and the methanol yield was 12.88%, all of which are superior to other catalysts. Its excellent performance can be attributed to the fact that CeO₂ enhances the metal-support interaction, increases the surface basicity, promotes the adsorption and activation of CO₂, and simultaneously inhibits the reverse water-gas shift side reaction. This study clarifies the structure-activity regulation mechanism of additive modification on Cu-ZnO catalysts, providing a theoretical basis and technical reference for the development of efficient catalysts for CO₂ hydrogenation to methanol.

Under the backdrop of “Carbon Peak and Carbon Neutrality” (dual carbon) goal in China, the methane-carbon dioxide reforming reaction has attracted considerable attention due to its environmental benefits of converting two greenhouse gases (methane and carbon dioxide) into syngas and its promising industrial applications. Nickel (Ni)-based catalysts, with high catalytic activity, low cost, and abundant resources, are considered ideal candidates for industrial applications. In this article, three reaction kinetic models were briefly introduced, namely the Power-Law (PL) model, the Eley-Rideal (ER) model, and the Langmuir-Hinshelwood-Hougen-Watson (LHHW) model. Based on the LHHW model, the reaction kinetics and mechanisms of different catalytic systems were systematically discussed, including the properties of supports, the doping of noble metals and transition metals, the role of promoters, and the influence of the geometric and electronic structures of Ni on the reaction mechanism. Furthermore, the kinetics of carbon deposition and elimination on various catalysts were analyzed. Based on the reaction rate expressions for carbon elimination, the reasons for the high activity of transition metal iron (Fe)-doped catalysts and core-shell structured catalysts in carbon elimination were explained. Based on the detailed collation and comparative analysis of the reaction mechanisms and kinetic characteristics across diverse Ni-based catalytic systems, a theoretical guidance for the designing of high-performance catalysts was provided in this work.

Catalytic decomposition of methane, which produces high-purity hydrogen and high-value-added carbon nanomaterials, has shown considerable potential for development and is expected to yield significant economic benefits in the future. However, designing catalysts that simultaneously exhibit high activity and long-term stability remains a significant challenge. Tuning the catalyst’s structure and electronic properties is an effective strategy for enhancing the reaction performance. In this work, a series of NixZr/ZSM-5 catalysts were prepared using the incipient wetness impregnation method, and the effect of Zr loadings on catalyst properties and performance was systematically investigated. The calcined and reduced catalysts were characterized by low-temperature N₂ adsorption-desorption, XRD, SEM, H₂-TPR and XPS. The results showed that the addition of Zr significantly increased the specific surface area of the catalyst and reduced the metal particle size. Smaller NiO particles were found to enter the pores of the HZSM-5 support, and electronic interactions between NiO and ZrO₂ markedly enhanced the metal-support interaction. The catalyst exhibited optimal catalytic performance at a Zr loading of 5%, achieving a maximum methane conversion of 68% at 625 °C, maintaining activity for 900 min, and delivering a carbon yield of 1927%. Further increasing the Zr loading yielded only limited improvements in catalytic performance. Characterization of the spent catalysts and carbon products via TEM, Raman spectroscopy, and TGA revealed that the introduction of ZrO₂ reduced metal sintering and promoted a shift in carbon nanofibers growth mode from tip-growth to base-growth. The mechanism of base-growth enabled the catalyst to maintain reaction activity for an extended period.

Cyclohexene is an important raw material in the production of nylon. Selective hydrogenation of benzene is a key method for preparing cyclohexene. However, the Ru catalysts used in current industrial processes still face challenges, including high metal usage, high process costs, and low cyclohexene yield. This study utilizes existing literature data combined with machine learning methods to analyze the factors influencing benzene conversion, cyclohexene selectivity, and yield in the benzene hydrogenation to cyclohexene reaction. It constructs predictive models based on XGBoost and Random Forest algorithms. After analysis, it was found that reaction time, Ru content, and space velocity are key factors influencing cyclohexene yield, selectivity, and benzene conversion. Shapley Additive Explanations (SHAP) analysis and feature importance analysis further revealed the contribution of each variable to the reaction outcomes. Additionally, we randomly generated one million variable combinations using the Dirichlet distribution to attempt to predict high-yield catalyst formulations. This paper provides new insights into the application of machine learning in heterogeneous catalysis and offers some reference for further research.