Bacterial cellulose-regulated synthesis of metallic Ni catalysts for high-efficiency electrosynthesis of hydrogen peroxide

Abstract

The decentralized production of H2O2via a two-electron oxygen reduction reaction (2e− ORR) has emerged as a promising alternative to the energy-intensive anthraquinone (AQ) process. However, its practical application requires 2e− ORR electrocatalysts with high activity and selectivity. Herein, we report the synthesis of metallic Ni nanoparticles anchored on bacterial cellulose-derived carbon fibers (Ni-NPs/BCCF) via a facile impregnation-pyrolysis method as efficient electrocatalysts for 2e− ORR to H2O2. By tuning the amount of Ni precursor, the best electrocatalytic performance toward 2e− ORR was achieved for Ni-NPs/BCCF-20.7, affording a high H2O2 selectivity of ∼90% and an onset potential of 0.75 V vs. reversible hydrogen electrode (RHE) in an alkaline electrolyte. Ni-NPs/BCCF-20.7 achieved the largest H2O2 yield rate of 162.7 ± 13.7 mmol gcat−1 h−1 and the highest Faradaic efficiency of 93.9% ± 4.2% at 0.2 and 0.5 V vs. RHE from the bulk ORR system, respectively. Theoretical calculations revealed the more favorable “end-on” adsorption configuration of molecular oxygen on the exposed Ni(111) plane, which can effectively suppress the O-O bond dissociation, resulting in high selectivity for H2O2 generation.