Atomically dispersed metal-nitrogen-carbon catalysts with d-orbital electronic configuration-dependent selectivity for electrochemical CO2-to-CO reduction
學年 111
學期 2
出版（發表）日期 2023-02-01
作品名稱 Atomically dispersed metal-nitrogen-carbon catalysts with d-orbital electronic configuration-dependent selectivity for electrochemical CO2-to-CO reduction
作品名稱（其他語言）
著者 Jialin Wang, Yu-Cheng Huang, Yiqing Wang, Hao Deng, Yuchuan Shi, Daixing Wei, Mingtao Li, Chung-Li Dong, Hui Jin, Samuel S. Mao, Shaohua Shen
單位
出版者
著錄名稱、卷期、頁數 ACS Catalysis 13(4), p.2374-2385
摘要 A variety of atomically dispersed transition-metal-anchored nitrogen-doped carbon (M–N–C) electrocatalysts have shown encouraging electrochemical CO2 reduction reaction (CO2RR) performance, with the underlying fundamentals of central transition-metal atom determined CO2RR activity and selectivity yet remaining unclear. Herein, a universal impregnation-acid leaching method was exploited to synthesize various M–N–C (M: Fe, Co, Ni, and Cu) single-atom catalysts (SACs), which revealed d-orbital electronic configuration-dependent activity and selectivity toward CO2RR for CO production. Notably, Ni–N–C exhibits a very high CO Faradaic efficiency (FE) of 97% at −0.65 V versus RHE and above 90% CO selectivity in the potential range from −0.5 to −0.9 V versus RHE, much superior to other M–N–C (M: Fe, Co, and Cu). With the d-orbital electronic configurations of central metals in M–N–C SACs well elucidated by crystal-field theory, Dewar–Chatt–Duncanson (DCD) and differential charge density analysis reveal that the vacant outermost d-orbital of Ni2+ in a Ni–N–C SAC would benefit the electron transfer from the C atoms in CO2 molecules to the Ni atoms and thus effectively activate the surface-adsorbed CO2 molecules. However, the outermost d-orbital of Fe3+, Co2+, and Cu2+ occupied by unpaired electrons would weaken the electron-transfer process and then impede CO2 activation. In situ spectral investigations demonstrate that the generation of *COOH intermediates is favored over Ni–N–C SAC at relatively low applied potentials, supporting its high CO2-to-CO conversion performance. Gibbs free energy difference analysis in the rate-limiting step in CO2RR and hydrogen evolution reaction (HER) reveals that CO2RR is thermodynamically favored for Ni–N–C SAC, explaining its superior CO2RR performance as compared to other SACs. This work presents a facile and general strategy to effectively modulate the CO2-to-CO selectivity from the perspective of electronic configuration of central metals in M–N–C SACs.
關鍵字 CO2 Reduction Reaction; Single-Atom Catalysts; Crystal-Field Theory; Electronic Configurations; CO Production
語言 en_US
ISSN 2155-5435
期刊性質 國外
收錄於 SCI
產學合作
通訊作者
審稿制度 否
國別 USA
公開徵稿
出版型式 ,電子版
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