Active Hydroxyl‐Mediated Preferential Cleavage of Carbon‐Carbon Bonds in Electrocatalytic Glycerol Oxidation
Qiang Zhang, Xiaojing Zhang, Baocang Liu, Baocang Liu, Peng Jing, Xuan Xu, Haigang Hao, Rui Gao, Rui Gao, Jun Zhang
Abstract
Abstract Electrocatalytic glycerol oxidation reaction (GOR) to produce high‐value formic acid (FA) is hindered by high formation potential of active species and sluggish C−C bond cleavage kinetics. Herein, Ni single‐atom (Ni SA ) and Co single‐atom (Co SA ) dual sites anchored on nitrogen‐doped carbon nanotubes embedded with Ni 0.1 Co 0.9 alloy (Ni 0.1 Co 0.9 @Ni SA Co SA ‐NCNTs) are constructed for electrochemical GOR. Remarkably, it can reach 10 mA cm −2 at a low potential of 1.15 V versus the reversible hydrogen electrode (vs. RHE) and realize a high formate selectivity of 93.27 % even at high glycerol conversion of 98.81 % at 1.45 V vs. RHE. The GOR mechanism and pathway are systematically elucidated via experimental analyses and theoretical calculations. It is revealed that the active hydroxyl (*OH) can be produced during the GOR. The Ni SA , Co SA , and Ni 0.1 Co 0.9 synergistically optimizes the electronic structure of Co SA active sites, reducing the energy barriers of *OH‐mediated cleavage of C−C bonds and dehydrogenation of C 1 intermediates. This decreases the number of reaction intermediates and reaction steps of GOR‐to‐FA, thus increasing the formate production efficiency. After coupling GOR with hydrogen evolution reaction in a membrane electrode assembly cell, 14.26 g of formate and 23.10 L of H 2 are produced at 100 mA cm −2 for 108 h.