Ruthenium Phosphide\nNanoclusters Dispersed on Zeolitic\nImidazolate Framework‑8 and Encapsulated in N,P‑Codoped\nCarbon as Electrocatalysts for the Hydrogen Evolution Reaction

Exploring highly active, durable, and low-cost hydrogen\nevolution\nreaction (HER) catalysts to replace platinum is beneficial for the\nrapid commercialization of proton exchange membrane water electrolysis.\nHerein, we develop an efficient catalyst featured with RuP nanoclusters\nencapsulated in N,P-codoped carbon (PA-RuP@NPC750) through phytic\nacid-assisted pyrolysis. Phytic acid coating cannot only control the\ngrowth of a RuP cluster within a subnanoscale (1.55 nm) during pyrolysis\nbut also strengthen the interaction between RuP clusters and the carbon\nmatrix. Due to the high intrinsic activity of the highly dispersed\nRuP nanoclusters, the as-designed PA-RuP@NPC750 only needs a low overpotential\nof 13.9 mV at 10 mA cm<sup>–2</sup> and shows a low Tafel slope\nof 31 mV dec<sup>–1</sup> in acidic media. Moreover, it displays\na remarkable mass activity of 1.881 mA g<sub>Ru</sub><sup>–1</sup> at an overpotential of 300 mV, which is 2.13 times that of commercial\nPt/C (0.8832 mA g<sub>Pt</sub><sup>–1</sup>). The big potential\nfor practical application is further confirmed by showing fine performance\nin a homemade PEM electrolyzer. The best performing PA-RuP@NPC750\ncan reach 0.5 and 1 A cm<sup>–2</sup> at cell voltages of 1.60\nand 1.74 V, respectively. This is comparable to an electrolyzer assembled\nwith commercial Pt/C as a cathode. Beyond that, the fine stability\nof PA-RuP@NPC750 enables long-term operation at industrial current\ndensity for over 150 h.