We developed a multicomponent, synergic PtRu/porous nitrogen-doped carbon catalyst (Pt0.25Ru0.75/pN-C) as the most active HOR catalyst in alkaline medium, surpassing the previous benchmark PtRu/C by 2-3 times. Spectroscopic, electrochemical, and gas chemisorption data suggest that the superior activity of Pt0.25Ru0.75/pN-C originates from a decrease of the HBE of Pt by charge transfer to Ru and an increase of water binding strength as well as optimization of interfacial water structure by single atoms on the pN-C support. An HEMFC with a low loading of Pt0.25Ru0.75/pN-C as the HOR catalyst and a commercial Fe-N-C ORR catalyst achieved a PPD of 1.46 W/cm 2 and a current density of 1.5 A/cm 2 at 0.65 V. The latter exceeds the US DOE 2022 target by by 50 % while under more stringent testing conditions. This function of the support in this catalyst, that is, introducing single atoms to facilitate substrate binding, goes beyond typical catalyst-support interactions. This strategy might find further applications in heterogeneous catalysis.