High-cost platinum-group noble-metal electrocatalysts remain widely used to overcome the ORR/OER overpotentials. wIn order to commercialize advanced energy systems successfully, noble-metal-based catalysts need to be replaced due to their high cost and low abundance. This topic has been extensively studied by scientific societies, leading to the development of various non-noble metal catalysts. Among the recently developed catalysts, M-N-C type materials show outstanding catalytic activity and exceptional stability, low cost, and a wide range of sources, making them desirable alternatives to platinum-based catalysts.

M-N-C type catalysts are typically made by doping/wet-impregnating carbon support with metal/nitrogen source followed by carbonization of the material. Another way is to form metal-organic species and pyrolyze them yielding M-N-C materials. However, most of the currently employed methods are solution-based, which raises many issues concerning sustainability: toxic/hazardous waste formation, time/energy expenses, excessive solvent use, and “green” large-scale production.

Here we propose a concept of a "green" and cost-effective route for producing Co-N-C-type catalysts with a bifunctional activity comparable to the recently developed materials. The method employs mechanochemistry via liquid-assisted grinding/compression (LAG and LAC) and NaCl as a “green” sacrificial templating agent. This study yielded a series of meso/microporous Co and N doped carbon materials – CoNC-LAG, 3D-CoNC-LAG, 3D-CoNC-LAC, and 3D-CoNC-LAG-LAC. From the obtained materials, the 3D-CoNC-LAG-LAC exhibited the best electrocatalytic efficiency with E_on of 0.98 V and E_1/2 of 0.83 V, and a high degree of porosity (S_A of 406 m²g^-1). A proposed method opens new avenues for environmentally sustainable large-scale implementation of high-performance M-N-C catalysts for clean energy systems.