Molecular metal–N_x centres in porous carbon for electrocatalytic hydrogen evolution

摘要

Replacement of precious platinum with efficient and low-cost catalysts for electrocatalytic hydrogen evolution at low overpotentials holds tremendous promise for clean energy devices. Here we report a novel type of robust cobalt–nitrogen/carbon catalyst for the hydrogen evolution reaction (HER) that is prepared by the pyrolysis of cobalt–N₄ macrocycles or cobalt/ o -phenylenediamine composites and using silica colloids as a hard template. We identify the well-dispersed molecular CoN _x sites on the carbon support as the active sites responsible for the HER. The CoN _x /C catalyst exhibits extremely high turnover frequencies per cobalt site in acids, for example, 0.39 and 6.5?s?1 at an overpotential of 100 and 200?mV, respectively, which are higher than those reported for other scalable non-precious metal HER catalysts. Our results suggest the great promise of developing new families of non-precious metal HER catalysts based on the controlled conversion of homogeneous metal complexes into solid-state carbon catalysts via economically scalable protocols.