Enhanced proton-feeding kinetics of metal-organic framework toward industrial-level H2O2 electrosynthesis for sustainable bleaching
F.T. Cheng, Yingnan Liu, Zilin Zhao, Xiaoxuan Yang, Wanzhen Zheng, Bin Yang, Zhongjian Li, Qinghua Zhang, Chung‐Li Dong, Lecheng Lei, Liming Dai, Yang Hou
Abstract
Eco-friendly electrocatalytic production of alkaline H2O2 via the two-electron oxygen reduction reaction offers a promising alternative to the conventional anthraquinone process, which is energy-intensive and poses explosion risks. However, the industrial adoption of this approach is hindered by sluggish proton-feeding kinetics of heterogeneous electrocatalysts, which restricts the achievable current densities. Herein, we develop Ni-based metal-organic frameworks with a bio-inspired B-coordination (B-NiBDC). The B-NiBDC shows Faradaic efficiency of ~90% for H2O2 electrosynthesis at 1000 mA cm−2, obtaining ~7.49 wt.% H2O2 alkaline solution for bleaching under urea oxidation-assisted energy-saving system. This has led to a significant increase in pulp brightness by 25-39 % (International Organization for Standardization, ISO). We propose that B-O-Ni motifs of B-NiBDC induce the formation of electron-deficient Ni active sites. Experiments and theoretical calculations elucidate that the electron-deficient Ni has accelerated water dissociation kinetics for proton-feeding to produce *OOH intermediate with suitable adsorption energy, boosting overall H2O2 electrosynthesis activity. Two-electron oxygen reduction reaction for hydrogen peroxide electrosynthesis is hindered by slow proton-feeding kinetics. Here, authors report bio-inspired B coordinated Ni-based metal-organic frameworks to accelerate water dissociation, achieving industrial-level hydrogen peroxide production.