Comparative Study of the Interaction of O2 and C2H4 with Small Vanadium Clusters from Density Functional Theory

Mechanistic insights into high-throughput screening of tandem catalysts for CO2 reduction to multi-carbon products

In carbon dioxide electrochemical reduction (CO2ER), since isolated catalysts encounter challenges in meeting the demands of intricate processes for producing multi-carbon (C2+) products, tandem catalysis is emerging as a promising approach. Nevertheless, there remains an insufficient theoretical understanding of designing tandem catalysts. Herein, we utilized density functional theory (DFT) to screen 80 tandem catalysts for efficient CO2ER to C2 products systematically, which combines the advantages of nitrogen-doped carbon-supported transition metal single-atom catalysts (M-N-C) and copper clusters. Three crucial criteria were designed to select structures for generation and transfer of *CO and facilitate C-C coupling. The optimal Cu/RuN4-pl catalyst exhibited an excellent ethanol production capacity. Additionally, the relationship between CO adsorption strength and transfer energy barrier was established, and the influence of the electronic structure on its adsorption strength was studied. This provided a novel and well-considered solution and theoretical guidance for the design of rational composition and structurally superior tandem catalysts.

Hierarchical Porous Wood Cellulose Scaffold with Atomically Dispersed Pt Catalysts for Low-Temperature Ethylene Decomposition

Despite the excellent catalytic properties of individual nanoparticles and atomic clusters, the current capabilities to assemble them into a complex system are insufficient for many practical applications. An objective of this work is to develop a fabrication technology that allows for the simultaneous control of the nanoparticle surface chemistry, elemental distribution, microscale geometry, and large-scale assembly. Using a cellulose structure derived from wood, we fabricate hierarchical porous cellulose scaffolds combining with cerium-doped TiO₂. This hybrid material serves as the support for atomically dispersed Pt catalysts and is used to successfully decompose ethylene at 0 °C. The fabrication concept developed in this work would allow mitigating the conflict between the required large active surfaces and the difficulties in handling nanopowders in environmental catalysis, including food preservation and indoor air purification. We thus discover a promising route to manufacture multifunctional materials with complex structures by combining a controllable chemical synthesis with the nature-designed wood scaffold.

Size-Dependent Reactivity of Nano-Sized Neutral Manganese Oxide Clusters toward Ethylene

Neutral manganese oxide clusters with the general composition Mn_2 N O_3 N+x (N=2-22; x=-1, 0, 1) with dimensions up to a nanosize were prepared by laser ablation and reacted with C₂ H₄ in a fast flow reactor. The size-dependent reactivity of C₂ H₄ adsorption on these clusters was experimentally identified and the adsorption reactivity decreases generally with an increase of the cluster size. Density functional theory calculations were performed to study the geometrical and electronic structures of the Mn_2 N O_3 N (N=1-6) clusters. The calculated results indicated that the coordination number and the charge distribution of the metal centers are responsible for the experimentally observed size-dependent reactivity. The highly charged Mn atoms with low coordination are preferential to adsorb C₂ H₄ . In contrast, the neutral manganese oxide clusters are completely inert toward the saturated hydrocarbon molecule C₂ H₆ . This work provides new perspectives to design related materials in the separation of hydrocarbon molecules.