Tan Xingxing, Jia Shunhan, Song Xinning, Ma Xiaodong, Feng Jiaqi, Zhang Libing, Wu Limin, Du Juan, Chen Aibing, Zhu Qinggong, Sun Xiaofu, Han Buxing
Beijing National Laboratory for Molecular Sciences, Key Laboratory of Colloid and Interface and Thermodynamics, Center for Carbon Neutral Chemistry, Institute of Chemistry, Chinese Academy of Sciences Beijing 100190 P. R. China
School of Chemical Sciences, University of Chinese Academy of Sciences Beijing 100049 P. R. China.
Chem Sci. 2023 Jul 10;14(30):8214-8221. doi: 10.1039/d3sc02790b. eCollection 2023 Aug 2.
Renewable-energy-driven CO electroreduction provides a promising way to address the growing greenhouse effect issue and produce value-added chemicals. As one of the bulk chemicals, formic acid/formate has the highest revenue per mole of electrons among various products. However, the scaling up of CO-to-formate for practical applications with high faradaic efficiency (FE) and current density is constrained by the difficulty of precisely reconciling the competing intermediates (COOH and HCOO). Herein, a Zn-induced electron-rich Sn electrocatalyst was reported for CO-to-formate with high efficiency. The faradaic efficiency of formate (FE) could reach 96.6%, and FE > 90% was maintained at formate partial current density up to 625.4 mA cm. Detailed study indicated that catalyst reconstruction occurred during electrolysis. With appropriate electron accumulation, the electron-rich Sn catalyst could facilitate the adsorption and activation of CO molecules to form a intermediate and then promoted the carbon protonation of to yield a HCOO* intermediate. Afterwards, the HCOO* → HCOOH* proceeded another proton-coupled electron transfer process, leading to high activity and selectivity for formate production.
可再生能源驱动的CO电还原为解决日益严重的温室效应问题和生产增值化学品提供了一条有前景的途径。作为大宗化学品之一，甲酸/甲酸盐在各种产品中每摩尔电子的收益最高。然而，将CO转化为甲酸盐以实现具有高法拉第效率（FE）和电流密度的实际应用，受到精确协调竞争性中间体（COOH和HCOO）的困难的限制。在此，报道了一种锌诱导的富电子Sn电催化剂用于高效将CO转化为甲酸盐。甲酸盐的法拉第效率（FE）可达96.6%，在甲酸盐分电流密度高达625.4 mA cm时，FE>90%得以保持。详细研究表明，电解过程中发生了催化剂重构。通过适当的电子积累，富电子的Sn催化剂可以促进CO分子的吸附和活化以形成中间体，然后促进的碳质子化以产生HCOO中间体。之后，HCOO→HCOOH*进行了另一个质子耦合电子转移过程，从而导致甲酸盐生产具有高活性和选择性。
