Ruthenium Phosphide Nanoclusters Dispersed on Zeolitic Imidazolate Framework-8 and Encapsulated in N,P-Codoped Carbon as Electrocatalysts for the Hydrogen Evolution Reaction

Exploring highly active, durable, and low-cost hydrogen evolution reaction (HER) catalysts to replace platinum is beneficial for the rapid commercialization of proton exchange membrane water electrolysis. Herein, we develop an efficient catalyst featured with RuP nanoclusters encapsulated in N,P-codoped carbon (PA-RuP@NPC750) through phytic acid-assisted pyrolysis. Phytic acid coating cannot only control the growth of a RuP cluster within a subnanoscale (1.55 nm) during pyrolysis but also strengthen the interaction between RuP clusters and the carbon matrix. Due to the high intrinsic activity of the highly dispersed RuP nanoclusters, the as-designed PA-RuP@NPC750 only needs a low overpotential of 13.9 mV at 10 mA cm–2 and shows a low Tafel slope of 31 mV dec–1 in acidic media. Moreover, it displays a remarkable mass activity of 1.881 mA gRu–1 at an overpotential of 300 mV, which is 2.13 times that of commercial Pt/C (0.8832 mA gPt–1). The big potential for practical application is further confirmed by showing fine performance in a homemade PEM electrolyzer. The best performing PA-RuP@NPC750 can reach 0.5 and 1 A cm–2 at cell voltages of 1.60 and 1.74 V, respectively. This is comparable to an electrolyzer assembled with commercial Pt/C as a cathode. Beyond that, the fine stability of PA-RuP@NPC750 enables long-term operation at industrial current density for over 150 h.