Inducing electronic asymmetricity on Ru clusters to boost key reaction steps in basic hydrogen evolution

Abstract

Modulating electronic asymmetricity of catalysts is a novel option to regulate the electrocatalytic performance. Nevertheless, the efficient regulation of asymmetric degree of heterostructured catalysts at the atomic level still remains challenging. Herein, Ru nanoclusters (NCs, average particle size of ∼ 1.3 nm) were anchored on carbon materials doped by controllable N functional groups to optimize the electronic asymmetricity toward efficient hydrogen evolution reaction (HER). The electronic interaction between Ru and N species, and hence, the asymmetric electronic distribution of Ru NCs is subjectively manipulated by precisely tailoring the type of N dopants, especially pyrrolic-N, of carbon substrates. As a result, the pyrrolic-N dominated Ru-based heterostructures exhibit excellent HER activity compared to most of the current Ru-based electrocatalysts in basic media. Multiple spectroscopy experiments and density functional theory simulations demonstrate that the asymmetric distribution of surface electron of Ru-based heterostructures not only accelerates H2O adsorption and dissociation at interfacial Ru sites with positive charge but also facilitates the adsorption behavior of hydrogen on surface Ru sites with negative charge, thereby simultaneously optimizing the elementary steps in basic HER process. The present findings would provide some crucial understanding in manipulating the local electronic asymmetricity toward reasonable design and fabrication of advanced catalysts and beyond.