Hydrogen\nStabilized RhPdH 2D Bimetallene Nanosheets\nfor Efficient Alkaline Hydrogen Evolution

Abstract

The design of catalysts with high\nactivity and robust stability\nfor alkaline hydrogen evolution reaction (HER) remains a great challenge.\nHere, we report an efficient catalyst of two-dimensional bimetallene\nhydrides, in which H atoms stabilize the rhodium palladium bimetallene.\nThe system exists because of the introduction of H that is in situ\nchemically released from the formaldehyde solution during the synthesis.\nThis provides a highly stable catalyst based on an unstable combination\nof metal elements. Density functional theory calculations show the\nH is confined by electronic interactions and the Miedema rule of reverse\nstability of the RhPd alloy. The obtained catalyst exhibits outstanding\nalkaline HER catalytic performance with a low overpotential of 40\nmV at 10 mA cm^–2 and remarkable stability for over\n10 h at 100 mA cm^–2. The experimental results show\nthat the confined H improve the activity, while the ultrathin sheet-like\nmorphology yields stability. Our work provides guidance for synthesizing\nhigh-activity catalysts by confining heteroatoms into the crystal\nlattice of bimetallene and also a very novel mechanism for the growth\nof bimetallene made of highly immiscible components.