One-step carbonization of ZIF-8 in Mn-containing ambience to prepare Mn, N co-doped porous carbon as efficient oxygen reduction reaction electrocatalyst

Abstract

Economical and efficient non-noble metal catalysts should be developed practically, instead of commercial Pt/C for fuel cells. In this paper, manganese, nitrogen co-doped porous carbon (Mn–N–C) was synthesized to catalyze oxygen reduction reaction (ORR) through the one-step carbonization of ZIF-8 in the Mn-containing (MnCl2) atmosphere. During the carbonization process, MnCl2 gas was captured with ZIF-8 and then transformed into uniform Mn–N active sites distributed in the porous carbon materials. The Mn–N–C catalyst exhibited plentiful porous structures, large specific surface areas, high graphitization and conductivity, which contributed to the transfer and transport of charge and exposed more active sites. The Mn–N–C catalyst exhibited superior catalytic ability in alkaline and acidic solutions. Half-wave potential of the Mn–N–C could reach 0.88 and 0.73 V in 0.1 M KOH and 0.5 M H2SO4, respectively. In addition, the Mn–N–C catalyst showed a prominent stability after the stability test of 18,000 s. Excellent electrochemical performance and endurance make the Mn–N–C expect to be an effective ORR catalyst to build high-performance fuel cells.