▎ 摘　　要

Pyrolyzed cobalt-nitrogen-carbon (Co-N-C) systems are considered as promising Pt-free electrocatalysts for oxygen reduction reaction (ORR) and hydrogen evolution reaction (HER). Here, we studied the possibility of using poly-5-aminoindole together with graphene oxide, multilayer graphene (MLG), or nitrogen-doped MLG (N-MLG) for the formation of Co-N-C electrocatalysts for both ORR and HER in acid electrolyte. Using 5-aminoindole with ammonium persulfate instead of pre-prepared polymer allows to simplify the synthesis of Co-N-C electrocatalysts, but causes the presence of Co9S8 particles in their composition. It was found that type of graphene-like precursor affects composition catalysts and the ratio of active sites, which leads to differences in their catalytic performance towards ORR and HER. The best efficiency of electrocatalyst derived from N-MLG for both ORR (onset potential of 795 mV, half-wave potential of 688 mV, and a Tafel slope of 73 mV/dec) and HER (overpotential of 207 mV at the current density of 10 mA/cm(2), and a Tafel slope of 69 mV/dec) is largely attributed to the highest content of pyridinic nitrogen in its composition, which is responsible for the formation of CoNx active sites. The obtained results allow to conclude that the same active sites of the prepared catalysts are participate in both HER and ORR.