45. Efficient Electrocatalytic Oxidation of Glycerol via Promoted OH* Generation over Single-Atom-Bismuth-Doped Spinel Co3O4

Y. Wang, Y.-Q. Zhu, Z. Xie, S.-M. Xu, M. Xu, Z. Li, L. Ma, R. Ge, H. Zhou, Z. Li, X. Kong, L. Zheng, J. Zhou, H. Duan*
ACS Catal. 2022, 12(19), 12432-12443.
DOI: 10.1021/acscatal.2c03162

Abstract
The renewable electricity-driven electrocatalytic oxidation of biomass represents a pathway to produce value-added chemicals from waste biomass such as glycerol (a byproduct of industrial biodiesel production). However, it remains difficult to design an efficient electrocatalyst with explicit structure–property relationships. Herein, we report a single-atom bismuth (Bi)-doping strategy to endow Co₃O₄ with enhanced activity and selectivity toward electrocatalytic glycerol oxidation reaction (GOR). Experimental characterizations and theoretical calculations reveal that single-atom Bi substitutes cobalt at octahedral sites (Co_Oh³⁺) in Co₃O₄, facilitating the generation of reactive hydroxyl species (OH*) at adjacent tetrahedral Co sites (Co_Td²⁺). Mechanism studies demonstrate that OH* accelerates the oxidation of hydroxyl groups and carbon–carbon (C–C) bond cleavage, achieving GOR activity (400 mA cm^–2 at 1.446 V vs reversible hydrogen electrode, RHE) and high faradaic efficiency of formate (97.05 ± 2.55%). Our study shows a promising way to promote the electro-oxidation activity of spinel oxides for biomass valorization by a single-atom doping strategy.