Controlled Electrocatalytic Glycerol Upgrading to Glyceraldehyde in Near Neutral Media by Cobalt Oxide Lattice Activation.

Abstract

Electrocatalytic upgrading of biomass-derived glycerol driven by renewable electricity offers a greatly attractive green way to produce value-added chemicals at much reduced global carbon footprint. However, achieving both the enhanced activity and selectivity for the most-valuable C3 product-glyceraldehyde (GAD) of glycerol oxidation reaction (GOR) in neutral media, though of great importance, is extremely challenging. In this work, we propose a Co₃O₄ lattice activation mechanism by introducing single atom Ru (0.36 wt%) into the tetrahedral sites (Co_Td) of Co₃O₄ lattice to significantly elevate the GOR activity and the GAD selectivity. The as-constructed Ru-Co₃O₄/NF only needs 1.16 V to achieve the current density of 10 mA cm^-2 during GOR and maintains ∼60% GAD selectivity (∼90% for C3 products) over a broad potential window, which are the highest reported in near neutral media. This excellent performance has been demonstrated to originate from the introduction of Ru atoms, which activates the lattice active sites of Co₃O₄ by promoting the rapid reconstruction of the catalyst to generate sufficient Co³⁺-(OH)_ads electrophilic oxygen species, resulting in not only the accelerated GOR kinetics, also largely enhanced selectivity of GAD by the adsorption configuration regulation of glycerol primary alcohols (C_α-OH) favoring the primary alcohol oxidation pathway.