韩国光州科技学院Chang Hyuck Choi开发了电化学CO2转化为CO单原子Ni活性位点的鉴定方法。 相关研究成果于2021年1月7日发表在《美国化学会志》。

电催化CO2转化为增值产品为可持续碳经济提供了新的范例。对于活性CO2电解，单原子Ni催化剂在实验中被认为是很有前途的催化剂，但理想化的Ni-N4位在理论上表现出不利的能量特征，导致了许多关于关于单原子Ni催化剂高活性化学性质的争论。

为了解决这个难题，研究人员研究了具有明确配位环境的四苯卟啉（N4-TPP）和21-氧杂四苯基卟啉（N3O-TPP）锚定的单原子Ni基催化剂的CO2电解。先进的光谱和计算研究表明，配体场对称性的破坏是高活性CO2电解的关键，导致产生NiI的Ni氧化还原电位的增加。除对催化剂的活性非常重要外，配体场的对称性和强度还与Ni中心的稳定性直接相关。

这意味着下一步在配位场强度领域寻求活性-稳定性图，合理设计单原子Ni催化剂的配体场对实现高效CO2电解至关重要。

附：英文原文

Title: Identification of Single-Atom Ni Site Active toward Electrochemical CO2 Conversion to CO

Author: Haesol Kim, Dongyup Shin, Woojin Yang, Da Hye Won, Hyung-Suk Oh, Min Wook Chung, Donghyuk Jeong, Sun Hee Kim, Keun Hwa Chae, Ji Yeon Ryu, Junseong Lee, Sung June Cho, Jiwon Seo, Hyungjun Kim, Chang Hyuck Choi

Issue&Volume: January 7, 2021

Abstract: Electrocatalytic conversion of CO2 into value-added products offers a new paradigm for a sustainable carbon economy. For active CO2 electrolysis, the single-atom Ni catalyst has been proposed as promising from experiments, but an idealized Ni–N4 site shows an unfavorable energetics from theory, leading to many debates on the chemical nature responsible for high activity. To resolve this conundrum, here we investigated CO2 electrolysis of Ni sites with well-defined coordination, tetraphenylporphyrin (N4–TPP) and 21-oxatetraphenylporphyrin (N3O–TPP). Advanced spectroscopic and computational studies revealed that the broken ligand-field symmetry is the key for active CO2 electrolysis, which subordinates an increase in the Ni redox potential yielding NiI. Along with their importance in activity, ligand-field symmetry and strength are directly related to the stability of the Ni center. This suggests the next quest for an activity–stability map in the domain of ligand-field strength, toward a rational ligand-field engineering of single-atom Ni catalysts for efficient CO2 electrolysis.

DOI: 10.1021/jacs.0c11008

Source: https://pubs.acs.org/doi/10.1021/jacs.0c11008