Hydroxylated Boron Crystal Domain-Modulated Heterostructure Carbon Catalysts for Efficient Hydrogen Peroxide Generation
Yuhan Wu, Qixin Yuan, Yuying Zhao, Kang Sun, Hao Sun, Kui Wang, Shengchun Hu, Geoffrey I. N. Waterhouse, Jingjie Wu, Ziyun Wang, Jianchun Jiang, Mengmeng Fan
Abstract
Metal-free heterostructure carbon catalysts are promising alternatives to metal-based catalysts for electrochemical hydrogen peroxide (H 2 O 2 ) synthesis via the two-electron oxygen reduction reaction (2e – ORR). However, one appropriate nanocrystal type is being sought to resolve a concern at industrial-level current densities. Herein, nano boron crystal domains (B n ) overcame the stability limitations of traditional carbon-based electrocatalysts for sustainable H 2 O 2 production and industrial application. A B n –C catalyst offered multiple active sites, while the nano B n imparted an O 2 enrichment effect enhancing mass transfer during ORR electrocatalysis. The B n –C exhibited a very high mass activity (11.6/10.7 mol g cat –1 h –1 ) in alkaline/neutral electrolytes and showed negligible loss in activity and Faradaic efficiency (over 90%) during 100 h continuous electrolysis at high current density (>300 mA cm –2 ). Density functional theory and in situ Raman experiments demonstrated that the –OH groups connecting nano B n provided an inductive effect on B atoms in the carbon matrix, alleviating a binding strength that is too strong with *OOH intermediate.