Surface Engineering over Metal–Organic Framework Nanoarray to Realize Boosted and Sustained Urea Oxidation

Abstract

Facilitating C─N bond cleavage and promoting *COO desorption are essential yet challenging in urea oxidation reactions (UORs). Herein a novel interfacial coordination assembly protocol is established to modify the Co-phytate coordination complex on the Ni-based metal–organic framework (MOF) nanosheet array (CC/Ni-BDC@Co-PA) toward boosted and sustained UOR electrocatalysis. Comprehensive experimental and theoretical investigations unveil that surface Co-PA modification over Ni-BDC can manipulate the electronic state of Ni sites, and in situ evolved charge-redistributed surface can promote urea adsorption and the subsequent C─N bond cleavage. Impressively, Co-PA functionalization can impart a negatively charged catalyst surface with improved aerophobicity, not only weakening *COO adsorption and promoting CO2 departure, but also repelling CO32− approaching to deactivate Ni species, eventually alleviating CO2 poisoning and enhancing operational durability. Beyond that, improved hydrophilic and aerophobic characteristics would also contribute to better mass transfer kinetics. Consequently, CC/Ni-BDC@Co-PA exhibits prominent UOR performance with an ultralow potential of 1.300 V versus RHE to attain 10 mA cm−2, a small Tafel slope of 45 mV dec−1, and strong durability, comparable to the best Ni-based electrocatalysts documented thus far. This work affords a novel paradigm to construct MOF-based materials for promoted and sustained UOR catalysis through elegant surface engineering based on a metal-PA complex.