Nest-type NCM ⊂ Pt/C with oxygen capture character as advanced electrocatalyst for oxygen reduction reaction

A unique nest-type catalyst has been designed with a nest of oxygen capture surrounding catalytic Pt centers, which shows much promoted performance, on the base of Pt/C catalyst, for oxygen reduction reaction (ORR). The nest is constructed with nitrogen-doped carbon matrix (NCM), derived from the controlled carbonization of PANI precursor, to cover Pt/C catalyst. The unique structure of the catalyst (denoted as NCM c Pt/C) has many merits. Firstly, it can capture oxygen both in air and in acidic elec-trolyte. Compared with naked Pt/C, it is found that, in air, the oxygen concentration within the porous nest of NCM surrounding Pt/C particles is-13 times higher than atmospheric oxygen concentration and, in acidic electrolyte, the concentration of activated oxygen over the catalyst NCM c Pt/C rise to-1.9 times. Secondly, the NCM nest offers a special electronic modulation on Pt centers toward modified ORR kinetics and then catalytic performances. With these merits, compared with Pt/C, the NCM c Pt/C catalyst shows 3.2 times higher turnover frequency value and 2.9 times enhanced specific activity for ORR with half-wave potential at 0.894 V. After 50,000 sweeping cycles, the NCM c Pt/C catalyst retains-66% mass activity and still has advantages over the fresh Pt/C catalyst. We envision that the nest-type catalyst provides a new idea for progress of practical Pt/C ORR catalyst.(c) 2022 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by ELSEVIER B.V. and Science Press.