Pt decorated POMOF-derived constructions for efficient electrocatalytic hydrogen evolution

Abstract

Molybdenum carbide (Mo₂C) has been universally investigated in the field of catalysis due to its d-band electronic structure, which is similar to those of Pt-group metals. However, practical application of Mo₂C in electrocatalytic hydrogen evolution is limited due to its low surface area and inadequate active sites caused by high temperature pyrolysis. Therefore, fabrication of Mo₂C-based nanostructures with well-defined morphologies and high porosity remains a great challenge. In this work, we developed an efficient approach for decorating Pt–Cu nanocrystals on Mo₂C octahedrons (Pt–Cu/Mo₂C) using thermal treatment of polyoxometalate (POM)-based metal–organic frameworks (NENU-5) followed by galvanic replacement with H₂PtCl₆. The Pt–Cu/Mo₂C nanostructure exhibits an ultrasmall overpotential of 12.9 mV (j = 10 mA cm⁻²) in an acidic medium for electrocatalytic hydrogen evolution, which is much lower than those of bare Mo₂C, Pt/Mo₂C, and commercial Pt/C catalysts. More importantly, the Pt–Cu/Mo₂C nanostructure delivers an exceptional cycling stability with a negligible decay over 10 000 cycles. The present work demonstrates potential guidance for the design of efficient and durable catalysts to boost electrocatalytic hydrogen evolution.