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Free keywords:
B/N co-doping; turbostatic carbon; oxygen reduction reaction; HO2 synthesis
Abstract:
Electrochemical oxygen reduction reaction (ORR) provides a green route for decentralized H2O2 synthesis, where astructure-selectivity relationship is pivotal for the control of a highly selective and active two-electron pathway. Here, we report the fabrication of a boron and nitrogen co-doped turbostratic carbon catalyst with tunable B-N-C configurations (CNB-ZIL) by the assistance of a zwitterionic liquid (ZIL) for electrochemical hydrogen peroxide production. Combined spectroscopic analysis reveals a fine tailored B-N moiety in CNB-ZIL, where interfacial B-N species in a homogeneous distribution tend to segregate into hexagonal boron nitride domains at higher pyrolysis temperatures. Based on the experimental observations, a correlation between the interfacial B-N moieties and HO2- selectivity is established. The CNB-ZIL electrocatalysts with optimal interfacial B-N moieties exhibit a high HO2- selectivity with small overpotentials in alkaline media, giving a HO2- yield of ~1787 mmol gcatalyst-1 h-1 at -1.4 V in a flow-cell reactor.
