Tuning the ratio of Bi/Bi 2 O 3 in Bi/PNC nanosheet for high-efficiency electrosynthesis hydrogen peroxide

Electrocatalytic two-electron oxygen reduction reaction (2e − ORR) is a promising method for producing green and sustainable H 2 O 2 but lacks high selectivity and yields electrocatalysts. And it is critical to develop catalysts that meet industrial demands. Herein, we report the different ratios of Bi 0 /Bi 3+ supported on a phosphorus, nitrogen, and carbon nanosheet (Bi/PNC), which can reduce O 2 to H 2 O 2 with high selectivity (up to 97.75% at 0.4 V RHE ) in 0.1 M KOH electrolyte and retain 97% selectivity even after 100 h electrolysis. Then a homemade flow-cell system was built for electrocatalytic production of H 2 O 2 under an O 2 atmosphere using an improved gas diffusion electrode. The Bi/PNC-4 can achieve a high H 2 O 2 yield of 2.76 mol·g catalyst −1 ·h −1 (alkaline), 5.29 mol·g catalyst −1 ·h −1 (neutral), and 3.50 mol·g catalyst −1 ·h −1 (acid) in universal pH conditions. The in-situ generated H 2 O 2 can function as a degradation agent for efficiently degrading pesticides and antibiotics. The outstanding selectivity and activities are attributed to the synergistic effects of Bi 0 and Bi 3+ that promote proton-coupled reduction of O 2 to OOH* (Δ G OOH* = 4.27 eV), and the formation of H 2 O 2 . The fast yield of H 2 O 2 on Bi/PNC catalysts in flow-cell provides a promising path of electrocatalytic 2e − ORR for practical H 2 O 2 production.