Graphene-nickel nitride hybrids supporting palladium nanoparticles for enhanced ethanol electrooxidation

Abstract

The AG-Ni 3 N hybrid was designed for anchoring Pd nanoparticles which exhibits outstanding performance for ethanol electrooxidation. In addition, the AG-Ni 3 N support promotes the adsorption of OH and then facilitates the oxidation removal of CO intermediates. Electrocatalysts for ethanol oxidation reaction (EOR) are generally limited by their poor durability because of the catalyst poisoning induced by the reaction intermediate carbon monoxide (CO). Therefore, the rapid oxidation removal of CO intermediates is crucial to the durability of EOR-based catalysts. Herein, in order to effectively avoiding the catalyst CO poisoning and improve the durability, the graphene-nickel nitride hybrids (AG-Ni 3 N) were designed for supporting palladium nanoparticles (Pd/AG-Ni 3 N) and then used for ethanol electrooxidation. The density functional theory (DFT) calculations demonstrated the introduction of AG-Ni 3 N depresses the CO absorption and simultaneously promotes the adsorption of OH species for CO oxidation removal. The fabricated Pd/AG-Ni 3 N catalyst distinctively exhibits excellent electroactivity with the mass catalytic activity of 3499.5 mA mg −1 on EOR in alkaline media, which is around 5.24 times higher than Pd/C (commercial catalyst). Notably, the Pd/AG-Ni 3 N hybrids display excellent stability and durability after chronoamperometric measurements with a total operation time of 150,000 s.