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

Nest-type catalyst NCM ⊂ Pt/C with a nest of nitrogen-doped carbon matrix (NCM) surrounding, which captures oxygen for Pt and offers special electronic modulation on Pt centers towards modified ORR performance. 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 ⊂ Pt/C) has many merits. Firstly, it can capture oxygen both in air and in acidic electrolyte. 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 ⊂ 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 ⊂ 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 ⊂ 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.