Atomic Bridging of Sn Single Atom with Nitrogen and Oxygen Atoms for the Selective Electrocatalytic Reduction of CO_(2)

The atomic coordination structure of single atom catalysts is crucial in modulating the electrocatalytic reduction of CO_(2)into desirable products.However,there remains limited insight into their roles and catalytic mechanisms.In comparison with commonly proposed metal-N4 moieties,herein the atomic bridging structure of nitrogen-tin-oxygen confined in porous carbon fibers is first presented for the selective reduction of CO_(2).With the detailed identification of such a unique structure,the in situ experimental results and theoretical calculations demonstrate that the bridging structure with reactive oxygen species enables the favorable surface electronic status to form adsorbed intermediate,*COOH for selective CO generation.Typically,the electrocatalyst displays high Faradaic efficiency in reducing CO_(2)into CO,but formate is produced on traditional Sn-based catalysts.Additionally,the solar-driven CO_(2)-H_(2)O system displays a desirable solar-to-CO conversion efficiency of 12.9%.This work provides fundamental guidance for the rational regulation of the atomic coordination structure to improve the production selectivity.

Outer delocalized electron aggregation of bromide bridged core–shell CuBr@C for hydrogen evolution reaction

Modulation of the surface electron distribution is a challenging problem that determines the adsorption ability of catalytic process.Here,we address this challenge by bridging the inner and outer layers of the core–shell structure through the bridge Br atom.Carbon shell wrapped copper bromide nanorods(CuBr@C)are constructed for the first time by chemical vapour deposition with hexabromobenzene(HBB).HBB pyrolysis provides both bridge Br atom and C shells.The C shell protects the stability of the internal halide structure,while the bridge Br atom triggers the rearrangement of the surface electrons and exhibits excellent electrocatalytic activity.Impressively,the hydrogen evolution reaction(HER)activity of CuBr@C is significantly better than that of commercial N-doped carbon nanotubes,surpassing commercial Pt/C at over 200 mA·cm^(−2).Density functional theory(DFT)calculations reveal that bridge Br atoms inspire aggregation of delocalized electrons on C-shell surfaces,leading to optimization of hydrogen adsorption energy.