Methanol electro-oxidation to formate on iron-substituted lanthanum cobaltite perovskite oxides

• Published in: eScience (Beijing) 2022-01, Vol.2 (1), p.87-94
• Main Authors: Meng, Fanxu, Dai, Chencheng, Liu, Zheng, Luo, Songzhu, Ge, Jingjie, Duan, Yan, Chen, Gao, Wei, Chao, Chen, Riccardo Ruixi, Wang, Jiarui, Mandler, Daniel, Xu, Zhichuan J.
• Format: Article
• Language: English
• Subjects: Electro-oxidation; Formate; Methanol; Oxides; Perovskite
• ISSN: 2667-1417; 2667-1417
• DOI: 10.1016/j.esci.2022.02.001

Electrochemically producing formate by oxidizing methanol is a promising way to add value to methanol. Noble metal-based electrocatalysts, which have been extensively studied for the methanol oxidation reaction, can catalyze the complete oxidation of methanol to carbon dioxide, but not the mild oxidation to formate. As a result, exploring efficient and earth-abundant electrocatalysts for formate production from methanol is of interest. Herein, we present the electro-oxidation of methanol to formate, catalyzed by iron-substituted lanthanum cobaltite (LaCo1−xFexO3). The Fe/Co ratio in the oxides greatly influences the activity and selectivity. This effect is attributed to the higher affinity of Fe and Co to the two reactants: CH3OH and OH−, respectively. Because a balance between these affinities is favored, LaCo0.5Fe0.5O3 shows the highest formate production rate, at 24.5 mmol ​h−1 goxide−1, and a relatively high Faradaic efficiency of 44.4% in a series of (LaCo1−xFexO3) samples (x ​= ​0.00, 0.25, 0.50, 0.75, 1.00) at 1.6 ​V versus a reversible hydrogen electrode. [Display omitted] •Electro-oxidation of methanol to formate is catalyzed by iron substituted lanthanum cobaltite (LaCo1−xFexO3).•The Fe/Co ratio in the oxides greatly influences the activity and selectivity.•DFT calculations revealed the influence of iron substitution on the activity and selectivity.•(LaCo0.5Fe0.5O3) shows the highest formate production rate of 24.5 mmol ​h−1 goxide−1 and a relatively high Faradaic efficiency of 44.4%.