An effective hybrid electrocatalyst for the alkaline HER: Highly dispersed Pt sites immobilized by a functionalized NiRu-hydroxide

Developing a highly active and robust catalyst for the hydrogen evolution reaction (HER) using the minimal amount of Pt is a continuing challenge. Herein, we demonstrate a functionalized NiRu-hydroxide (NiRu-OH) catalyst that acts as a capable candidate to immobilize highly dispersed single Pt atoms. We synthesize this catalyst by means of Ru leaching from a NiRu-layer double hydroxide (NiRu-LDH) under oxygen evolution reaction (OER) conditions. The hybrid catalyst shows extremely high HER activity, with an overpotential of 38 mV to drive a typical current density of 10 mA cm(geo)(-2) in alkaline media. We ascribe the excellent catalytic activity to the synergistic effect of the highly dispersed single Pt atoms and NiRu-OH in a dual-site alkaline HER mechanism. This work forms the basis for the exploration of matrices capable of trapping single atoms for various applications.