Regulating Competitive Adsorption on Pt Nanoparticles by Introducing Pb to Expedite Hydrogen Production via Ammonia Oxidation

Ammonia with a high hydrogen content is an ideal hydrogen carrier due to its mature storage and transport system. Ammonia electrooxidation is one of the most promising technologies for green and economic H2 production. However, ammonia oxidation reaction (AOR) is limited to a narrow potential window due to the slow kinetics and the competitive adsorption between the reactant and Had/OHad on active sites. Herein, an ultra-small PtPb alloy nanocatalyst is synthesized for AOR by the facile one-step solvothermal method. Experimental results demonstrate that the electronic structure of Pt is regulated by the introduction of Pb, inhibiting the competitive adsorption on Pt sites. Therefore, it exhibits improved AOR activity with a peak current density of 191.2 mA mg–1Pt at 10 mV s–1, which is 1.97 times that of Pt/C. The good performance is attributed to the high hydrogen evolution overpotential property of Pb and the strong p–d electron interaction of PtPb, which effectively modulates the adsorption/desorption of intermediates at the Pt site. Hence, this work proposes a simple and effective strategy for designing efficient AOR catalysts, promoting the development of H2 production by AOR.