P and Mo Dual Doped Ru Ultrasmall Nanoclusters Embedded in P‐Doped Porous Carbon toward Efficient Hydrogen Evolution Reaction

Abstract Rational design of efficient hydrogen evolution reaction (HER) electrocatalysts for mass production of hydrogen via electrochemical water splitting is a challenging but pressing task. Herein, an in situ dual doping engineering from phosphomolybdic acid encapsulated within the bimetallic metal‐organic‐frameworks strategy to synthesize P,Mo dual doped Ru ultrasmall nanoparticles embedded in P‐doped porous carbon (P,Mo‐Ru@PC) for efficient HER is proposed. As a result, P,Mo‐Ru@PC achieves a low overpotential of 21 at 10 mA cm −2 , low Tafel slopes of 21.7 mV dec −1 , and a mass activity about 22 times greater than that of commercial 20 wt% Pt/C in alkaline media. First principle calculations demonstrate that introducing Mo and P atoms into Ru lattices triggers the in situ electron donation from Ru to Mo and P and consequently reduces the energy barrier for the HER.