Composition-dependent hydrogen oxidation activity of Pt-Cu nanoparticles prepared using boron-rich nanosheets

Abstract

Pt and Pt-Cu alloy nanoparticles (NPs) were synthesized via a scalable aqueous co-reduction process using boron-rich nanosheets (BNS). The aqueous-derived BNS react with PtCl62- to form Pt NPs and with Cu2+ to form a BNS-bound Cu(I/II) complex. When both metal precursors are present, metallic Cu is incorporated into Pt-Cu NPs, with Pt catalyzing the reduction of Cu2+. Alloy composition was systematically varied to evaluate catalytic performance for the hydrogen oxidation reaction (HOR) in alkaline media. The optimal Pt77Cu23/BNS catalyst composition exhibits high Pt surface specific activity, outperforming both Pt/BNS and a commercial Pt/C catalyst. Our DFT calculations atribute the enhanced HOR activity to composition-dependent tuning of the d-band center, which modulates the adsorption strength of reaction intermediates