Ma Jiaxing, Liu Tianyang, Hao Shuya, Yan Shuai, Xu Zikai, Yang Songtao, Shen Haifeng, Jing Yu, Peng Chen
Laboratory of Advanced Materials and Department of Chemistry, Fudan University, Shanghai, 200438, China.
Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, College of Chemical Engineering, Nanjing Forestry University, Nanjing, 210037, China.
ChemSusChem. 2024 Nov 11;17(21):e202400683. doi: 10.1002/cssc.202400683. Epub 2024 Jun 10.
The efficient acetate conversion from CO electroreduction is challenging due to the poor selectivity at high reaction rate, which requires the competition with H and other C (i. e., ethylene, ethanol, n-propanol) reduction products. Electrolyte engineering is one of the efficient strategies to regulate the reaction microenvironment. In this work, the adding of sulfite (SO ) with high nucleophilicity in KOH electrolytes was demonstrated to enable improving the CO-to-acetate conversion via generating a S-O chemical bond between SO and oxygenated *C intermediates (i. e., *CO-CO, *CO-COH) compared with that in pure KOH system on both synthesized Cu(200)- and normal commercial Cu(111)-facets-exposed metallic Cu catalysts. As a result, the prepared Cu(200)-facets-exposed metallic Cu catalyst with surface ions modification showed an superior Faradaic efficiency of 63.6 % at -0.6 A ⋅ cm, and extraordinary absolute value of peak partial current density as high as 1.52 A ⋅ cm with adding SO in KOH electrolytes, compared to the best reported values in both CO and CO electroreduction. Our work suggests an attractive strategy to introduce the oxyanion with high nucleophilicity in electrolytes to regulate the microenvironment for industrial-current-density electrosynthesis of acetate from CO electroreduction.
由于在高反应速率下选择性较差，将CO电还原高效转化为乙酸具有挑战性，这需要与H和其他C（即乙烯、乙醇、正丙醇）还原产物竞争。电解质工程是调节反应微环境的有效策略之一。在这项工作中，与纯KOH体系相比，在KOH电解质中添加具有高亲核性的亚硫酸盐（SO）被证明能够通过在SO与含氧C中间体（即CO-CO、*CO-COH）之间形成S-O化学键来提高CO到乙酸的转化率，这一结论在合成的Cu(200)和普通商用Cu(111)晶面暴露的金属Cu催化剂上均得到验证。结果表明，在KOH电解质中添加SO后，制备的具有表面离子修饰的Cu(200)晶面暴露的金属Cu催化剂在-0.6 A·cm时显示出63.6%的优异法拉第效率，以及高达1.52 A·cm的峰值分电流密度绝对值，与CO和CO电还原中报道的最佳值相比更优。我们的工作提出了一种有吸引力的策略，即在电解质中引入具有高亲核性的含氧阴离子来调节微环境，以实现工业电流密度下由CO电还原合成乙酸。
