The preparation of pN-C is described in detail in the Supplementary Information. To synthesize the catalyst, the pN-C or Vulcan XC-72R and PGM salts (RuCl3• xH2O and H2PtCl6• xH2O) with desired mass ratio were dispersed in H2O to form homogeneous dispersions. The solutions were lyophilized to remove water and gave PGM/pN-C or PGM/C precursors. The precursors were then placed on the center of a tube furnace and heated with a ramp rate of 10 ℃/min to a desired temperature for a certain time (listed below in Table ) under a 5% H2/95% N2 atmosphere. Varying the H2 concentration (2.5%, 10 %, 100 %) don't change the performance of the resulting samples. After cooling down to room temperature, a small amount of ethanol was injected to the products before taking them out from the tube furnace to prevent pyrophoric oxidation.