Interfacial Engineering of ZrO2@Co-MOF Heterostructures for Highly Selective Electrocatalytic Glycerol Oxidation to Formic Acid

Abstract

The selective electrocatalytic oxidation of glycerol (GOR) into high-value chemicals is crucial for sustainable biorefineries, yet achieving high selectivity, particularly for C1 products like formic acid, remains a significant challenge. Herein, we report the rational design and facile one-step hydrothermal synthesis of ZrO2@Co-MOF heterostructures, where ZrO2 nanoparticles act as core sites influencing Co-MOF growth. The optimized ZrO2@Co-MOF(0.11) catalyst exhibits unprecedented performance for GOR, achieving 98.7% selectivity and near-unity Faradaic efficiency for formic acid production at industrially relevant current densities, alongside excellent long-term stability. Comprehensive electrochemical evaluations, ex-situ characterizations, and in-situ/operando spectroscopic investigations reveal a pivotal innovation: the ZrO2 interface not only modulates the electronic structure of Co centers and tailors MOF morphology but, critically, directs and stabilizes the in-situ electrochemical reconstruction of the Co-MOF into highly active CoOOH/Co(COO)2 species. Furthermore, theoretical calculations elucidate that this engineered interface significantly lowers the energy barrier for critical C-C bond cleavage, thereby suppressing C3 intermediates and driving the reaction pathway selectively toward formic acid. This work unveils a powerful strategy in hetero-interfacial engineering of MOF-derived materials for precise and efficient biomass valorization.