Advanced Ultrathin RuPdM (M = Ni, Co, Fe) Nanosheets Electrocatalyst Boosts Hydrogen Evolution

Abstract

The hydrogen evolution reaction (HER) is one of the most significant reactions in the electrolysis water process, and electrocatalysts which possess high mass activity and excellent stability are the most important driving factors to improve the efficiency of HER. As for the efficient commercially electrocatalyst, Pt/C is limited in development because of its high cost. Therefore, the study of non-Pt high-efficiency catalysts is particularly important at this moment. Here, we creatively report for the first time a kind of RuPdM (M= Ni, Co, Fe) ultrathin nanosheets (NSs), which exhibit extraordinary electrochemical properties for HER under alkaline conditions. The overpotential of optimized trimetallic Ru38Pd34Ni28 ultrathin NSs is only 20 mV (10 mA cm-2), and the mass activity reaches 6.15 A mg-1noble metal at -0.07 V vs RHE. It can be compared to Pt-based electrocatalysts, which have the highest mass activity currently reported. The durability tests also prove that the stability of the electrocatalyst is outstanding. DFT calculations disclose that the flexible modulation of electronic structures of RuPd ultrathin NSs is achieved by utilizing the additional 3d transition metals Fe, Co, and Ni. In particular, the Ni-3d bands act as the continuous electron-supply center for Ru to ensure an efficient electron transfer toward the adsorbates. Meanwhile, the stable Pd sites are critical for coupling the O-2pπorbital in the initial H2O splitting with a facile barrier. This work will open up a new era of non-Pt materials for alkaline hydrogen evolution toward practical application.