Author:

Keywords:

Science & Technology, Physical Sciences, Chemistry, Multidisciplinary, Chemistry, B, N Co-Doping, H2O2 Synthesis, Oxygen Reduction Reaction, Turbostratic Carbon, OXYGEN REDUCTION REACTION, IONIC LIQUIDS, ELECTROCATALYTIC SYNTHESIS, H2O2 PRODUCTION, DOPED CARBON, GRAPHENE, NITRIDE, SELECTIVITY, CATALYSTS, LAYERS, B/N Co-Doping, 03 Chemical Sciences, Organic Chemistry, 34 Chemical sciences

Abstract:

The electrochemical oxygen reduction reaction (ORR) provides a green route for decentralized H2 O2 synthesis, where a structure-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.