Unraveling the Function of Metal–Amorphous Support Interactions in Single-Atom Electrocatalytic Hydrogen Evolution

Abstract

© 2021 Wiley-VCH GmbH.Amorphization of the support in single-atom catalysts is a less researched concept for promoting catalytic kinetics through modulating the metal–support interaction (MSI). We modeled single-atom ruthenium (RuSAs) supported on amorphous cobalt/nickel (oxy)hydroxide (Ru-a-CoNi) to explore the favorable MSI between RuSAs and the amorphous skeleton for the alkaline hydrogen evolution reaction (HER). Differing from the usual crystal counterpart (Ru-c-CoNi), the electrons on RuSAs are facilitated to exchange among local configurations (Ru-O-Co/Ni) of Ru-a-CoNi since the flexibly amorphous configuration induces the possible d–d electron transfer and medium-to-long range p–π orbital coupling, further intensifying the MSI. This embodies Ru-a-CoNi with enhanced water dissociation, alleviated oxophilicity, and rapid hydrogen migration, which results in superior durability and HER activity of Ru-a-CoNi, wherein only 15 mV can deliver 10 mA cm−2, significantly lower than the 58 mV required by Ru-c-CoNi.