Latest ArticlesThis work demonstrates a two-step method to produce oxide-derived Cu nanowires on Cu mesh surface to offer a monolithic catalyst that outstandingly improves the hydrogen production from reforming formaldehyde and water under ambient conditions. Our results not only reveal that the special oxide-derived nanostructure can significantly improve the formaldehyde reforming performance of Cu, but also display that the hydrogen production has a linear relationship with oxygen pressure. Specially, a maximum of 36 times increment in hydrogen generation rate is observed than that without oxygen during the reaction. Density functional theory calculations show that the formaldehyde molecule is adsorbed on Cu surface only when the adsorbed oxygen is in adjacency, and hydrogen release process is the rate-determining step. This work highlights that the activity of deliberately synthesized catalyst can further be promoted by dynamic chemical modulation of surface states during working.
Developing redox switches that not only perform specific mechanical movements but also drive important chemical reactions is important but a great challenge. Herein, we report a redox pair of cobalt species (CoⅢ/CoⅡ) that switches through photo-dehydrogenation of alcohol and hydrogenation of azo-ligand. The cobalt species is equipped with a flexible azo-ligand containing two bulky planar substituents. A planar oxidated sate (CoⅢ species) can be photo-reduced to a saddle-like reduced state (CoⅡ) with alcohol molecules as electron donors, and in turn the CoⅢ species can be recovered with azo-ligand as oxidant under acidic surrounding. Both the redox states of the pair are isolated and characterized by single crystal X-ray diffraction. In the switching cycle, alcohol is oxidized to aldehyde by azo-ligand through proton coupled electron transfer and the cobalt complex acts as a redox catalyst. These results provide important insights into alcohol dehydrogenation catalyzed by redox complexes.
Using a ditopic organic linker 4-(1H-pyrazol-4-yl)benzoic acid (H2pba), FICN-6, a metal-organic framework containing both Cu2(O2CR)4 and Cu3(OH)(pyz)3(O2CR) secondary building units (SBUs), was synthesized. FICN-6 adopts in an unusual intercatenated structure with SBUs from two distinct networks connecting to each other. Presence of Cu3 clusters makes FICN-6 a good heterogeneous catalyst for oxygen activation and aerobic oxidative C-C coupling of organic boronic acids.
Quantum dots (QDs) based heterojunction is a candidate for the photocatalytic CO2 reduction, owing to the large extinction coefficient and easy modification of band structures. However, the van der Waals interaction causes the large charge resistance and strong recombination centers between QDs and host materials, which makes the poor photocatalytic performance. Herein, a covalent bonded CdSeTe QDs and NH2-UiO-66 heterojunction (NUC-x) is constructed through an acylamino (-CONH-). The results indicate that the acylamino between NH2-UiO-66 and CdSeTe QDs can serve as the transfer channels for the photogenerated charges and stabilize the QDs. The optimized NUC-1200 achieved a CO generation rate of 228.68 µmol/g, which is 13 and 4 times higher than that of NH2-UiO-66 and CdSeTe QDs, respectively. This work provides a new avenue for efficient and stable photocatalysis of QDs.
Efficient cathode-catalysts with multi-functional properties are essential for Li-CO2 battery, while the construction of them with simultaneously enhanced CO2 reduction and evolution kinetics is still challenging. Here, a kind of hybrid nanosheets based on Ru nanoparticles, Fe-TAPP and grapheme oxide (GO) has been designed through a one-pot self-assembly strategy. The Ru, Fe-porphyrin and GO based hybrid nanosheets (denoted as Ru/Fe-TAPP@GO) with integrated multi-components offer characteristics of ultrathin thickness (~4 nm), high electro-redox property, uniformly dispersed morphology, and high electrical conductivity, etc. These features endow Ru/Fe-TAPP@GO with ultra-low overpotential (0.82 V) and fully reversible discharge/charge property with a high specific-capacity of 39,000 mAh/g within 2.0–4.5 V at 100 mA/g, which are much superior to Ru@GO and Fe-TAPP@GO. The achieved performance was presented as one of the best cathode-catalysts reported to date. The synergistically enhanced activity originated from the integrated hybrid nanosheets may provide a new pathway for designing efficient cathode-catalysts for Li-CO2 batteries.
A series of heterotrinuclear Ti2Ni(CO)n– (n = 6–9) carbonyls have been generated via a laser vaporization supersonic cluster source and characterized by mass-selected photoelectron velocity-map imaging spectroscopy. Quantum chemical calculations have been carried out to identify the structures and understand the experimental spectral features. The results indicate that a building block of Ti-Ti-Ni-C four-membered ring with the C atom bonded to Ti, Ti, and Ni is dominated in the n = 6–8 complexes, whereas a structural motif of Ti-Ti-Ni triangle core is preferred in n = 9. These complexes are found to be capable of simultaneously accommodating all the main modes of metal-CO coordination (i.e., terminal, bridging, and side-on modes), where the corresponding mode points to the weak, moderate, high CO bond activation, respectively. The number of CO ligands for a specific bonding mode varies with the cluster size. These findings have important implications for molecular-level understanding of the interaction of CO with alloy surfaces/interfaces and tuning the appropriate CO activation via the selection of different metals.
Lithium-rich manganese-based material shows great potential as the high specific cathode materials due to its low cost, environmental friendliness, high operating voltage and simple preparation process. However, the poor capacity retention and cycling performance caused by its unstable structure during cycling restrict the commercialization. In this work, Li1.2Ni0.16Mn0.56Co0.08O2 was synthesized utilizing a Co-precipitation method and different amount of La(PO3)3 (La(PO3)3 = 2 wt%, 4 wt% and 6 wt%) was selected as the coating layer to resolve the above issues. During the calcination process, La(PO3)3 reacts with impurities such as LiOH and Li2CO3 on the lithium-rich surface to reduce the residual lithium on the surface, thus improving the interfacial stability, slowing down the corrosion of the electrolyte, and finally enhancing its electrochemical performance. The cathode materials coated with 4% of La(PO3)3 showed the best electrochemical performance in terms of capacity retention and cycling performance compared to the pristine NCM. The high initial discharge capacity of 214.21 mAh/g and capacity retention of 94.2% after 100 cycles at 0.1 C can be obtained. This work provides an effective strategy to protect the cathode from corrosion and will promote its further practical applications in high specific Li-ion batteries.
The construction of highly active catalysts for methanol oxidation reaction (MOR) is central to direct methanol fuel cells. Tremendous progress has been made in transition metal phosphides (TMPs) based catalysts. However, TMPs would be partially damaged and transformed into new substances (e.g., Pt-M-P composite, where M represents a second transition metal) during Pt deposition process. This would pose a large obstacle to the cognition of the real promoting effects of TMPs in MOR. Herein, Co2P co-catalysts (Pt-P/Co2P@NPC, where NPC stands for N and P co-doped carbon) and Pt-Co-P composite catalysts (Pt-Co-P/NPC) were controllably synthesized. Electrocatalysis tests show that the Pt-Co-P/NPC exhibits superior MOR activity as high as 1016 mA/mgPt, significantly exceeding that of Pt-P/Co2P@NPC (345 mA/mgPt). This result indicates that the promoting effect is ascribed primarily to the resultant Pt-Co-P composite, in sharply contrast to previous viewpoint that Co2P itself improves the activity. Further mechanistic studies reveal that Pt-Co-P/NPC exhibits much stronger electron interaction and thus manifesting a remarkably weaker CO absorption than Pt-P/Co2P@NPC and Pt/C. Moreover, Pt-Co-P is also more capable of producing oxygen-containing adsorbate and thus accelerating the removal of surface-bonded CO*, ultimately boosting the MOR performance.
A regiodivergent hydrophosphorylation of enynes with phosphites has been developed using earth-abundant nickel catalyst. The manipulation of regioselectivity can be achieved by regulating the insertion order of alkyne bonds with (RO)2P(O)–Ni–H or R2P(O)O–Ni–H species, respectively. Under the Ni/Xantphos catalysis, 4,1-hydrophosphorylation is selectively obtained while the adding of acid can promote reactions towards 1,2-addition. By employing an additional Pd–H catalysis, 2,1-hydrophosphorylation is also an accessible task in one-pot reaction. Mechanistic studies and analysis have also been performed to interpret the origin of the regioselective regulation. This work highlights the arts in accessing different regioisomers by diverting common elementary reaction steps.
Three discrete tetrahedral metallo-supramolecular cages were designed and constructed using truxene-pended base ligands. Owing to the synergistic rigidifying effect of unsymmetric cyano-substituted oligo(p-phenylene-vinylene) (u-COPV) suspended by the truxene skeleton, the resulting supramolecular cages were confirmed to exhibit significant aggregation-induced emission (AIE) accompanied by an interesting solvatochromic fluorescent behavior as well as a porous honeycomb-like state during aggregation. In particular, the anti-counterfeiting performance and emission behaviors of the cages in the solid state under external hydrostatic pressure were investigated.
No. 86 Xueyuan South Road, Haidian District, Beijing
010-62199257
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
