银掺杂镍的硫醇盐类团簇用于非均相电催化二氧化碳还原

Silver-doped nickel thiolates as electrocatalysts for heterogeneous CO2 reduction

精细调控具有原子尺度精确的团簇结构并将其应用于非均相催化研究,对于从分子水平阐明催化反应机制,明确催化反应活性位具有重要意义.本文基于环已硫醇保护的Ni_(4)团簇体系,成功制备了一种全新的Ni_(3)Ag_(2)双金属团簇,该团簇为Ni_(4)团簇中一个Ni原子被两个Ag原子取代的结果.研究发现将该团簇用于非均相电催化二氧化碳还原,Ni_(3)Ag_(2)双金属团簇催化二氧化碳还原产生一氧化碳的法拉第效率可达90%以上,而母体结构Ni_(4)团簇的催化产物主要为氢气.对照实验与DFT理论计算结果表明,电解中去配体过程对于Ni_(3)Ag_(2)团簇的高选择性催化具有重要作用.其催化二氧化碳选择性还原的主要活性位为去配体后暴露出的Ni原子而非Ag原子.

Electrochemical CO_(2)reduction reaction(CO_(2)RR)via renewable electricity offers an attractive strategy to produce value-added chemicals while mitigating greenhouse gas emissions[1–5].Over the past decades,efforts have been dedicated to developing highly efficient heterogeneous electrocatalysts for CO_(2)RR and various micro-/nanosized particles or hierarchical materials are reported.However,most of the surface structures of the developed catalysts cannot be precisely controlled,which makes the investigation of the structure-activity relationship difficult.Recently,metallic nanoclusters have attracted increasing research interest owing to their atomically precise characteristics and fundamental structure-related physicochemical properties[6–8].Utilizing nanoclusters as the catalysts for CO_(2)RR gives the chance to understand the precise active sites of the elementary catalytic reactions[5,9–15],which could guide the further designs of the catalyst to improve the efficiency.