LAUSR

Tuning the chemical microenvironment of dual‐atom catalysts is a significant challenge in boosting electrocatalytic hydrogen evolution reaction (HER). Here, a “space guarding” strategy is proposed to precisely place Pt‐Ru dual‐atom pair sites confined in W2N lattice using polyoxometalates (POMs) K10[Zn4(H2O)2(PW9O34)2] as a rigid template. The pre‐reserved localized defects capture Pt‐Ru pair site and provide the specific W‐Pt‐N‐Ru coordination environment. The obtained PtRu@W2NDF@NC catalyst exhibits superior performance with an unprecedented mass activity of 72.7 A mg(Pt+Ru)−1 in 0.5 M H2SO4 and stable electrochemical HER performance for 1200 h. With insights from in‐situ Raman spectroscopy and theoretical calculations, the overall hydrogen evolution pathway proceeds along three steps: fast H2O adsorption on W site, facile H* and OH* respective migration from W site to Pt and Ru sites via its distinct electronic flows, and favorable H2 desorption on Pt site. This work demonstrates a dual‐atom placing strategy via precise lattice‐confinement for the construction of high‐performance HER electrocatalysts.