In situ modulation of Pt-Ni heterocatalysts on highly graphitized wood-derived carbon platform to boost hydrogen production

Abstract

Although Pt is an ideal electrocatalyst for hydrogen evolution reaction (HER), in addition to high cost and scarcity, Pt nanocatalysts suffer from low water dissociation rates and poor stability. Herein, we used graphitized wood-derived carbon (GWC) as a platform to construct dual-active catalytic sites via Pt-Ni recombination and modulate interactions of heterointerface atoms through in situ phase transition to improve HER activity and durability of Pt nanocatalysts. Specifically, Ni(OH)2 nanosheets were grown on GWC; then, Pt nanoparticles were introduced and converted in situ into Pt-Ni(PO3)2-GWC. As expected, the catalyst exhibited excellent HER activity, requiring only 10 mV (overpotential) to reach a current density of 10 mA cm–2 and excellent durability over 120 h. DFT calculations further revealed that in situ converted Pt and Ni(PO3)2 heterointerface tuned the electronic structure of interface atoms and synergistically promoted water dissociation and hydrogen adsorption. Notably, Pt-Ni(PO3)2-GWC can be used as a bifunctional catalyst for overall urea electrolysis, and the assembled electrolytic cell exhibited high-efficiency hydrogen production performance, requiring a cell voltage of only 1.39 V to reach a current density of 10 mA cm–2. These findings will provide new insights into the development of highly efficient, stable catalysts for energy-saving hydrogen production.