Engineering of crystal phase over porous MnO2 with 3D morphology for highly efficient elimination of H2S

Xiaohai Zheng; Guanqing Zhang; Zheng Yao; Yong Zheng; Lijuan Shen; Fujian Liu; Yanning Cao; Shijing Liang; Yihong Xiao; Lilong Jiang

doi:10.1016/j.jhazmat.2021.125180

Engineering of crystal phase over porous MnO₂ with 3D morphology for highly efficient elimination of H₂S

J Hazard Mater. 2021 Jun 5:411:125180. doi: 10.1016/j.jhazmat.2021.125180. Epub 2021 Jan 19.

Authors

Affiliations

¹ National Engineering Research Center of Chemical Fertilizer Catalyst, Fuzhou University, Fuzhou, Fujian 350002, PR China.
² National Engineering Research Center of Chemical Fertilizer Catalyst, Fuzhou University, Fuzhou, Fujian 350002, PR China; Fujian Key Laboratory of Pollution Control & Resource Reuse, College of Environmental Science and Engineering, Fujian Normal University, Fuzhou, Fujian 350007, PR China. Electronic address: syhgslj@fzu.edu.cn.
³ National Engineering Research Center of Chemical Fertilizer Catalyst, Fuzhou University, Fuzhou, Fujian 350002, PR China. Electronic address: sjliang2012@fzu.edu.cn.

PMID: 33858115
DOI: 10.1016/j.jhazmat.2021.125180

Abstract

In the present work, we report a facile oxalate-derived hydrothermal method to fabricate α-, β- and δ-MnO₂ catalysts with hierarchically porous structure and study the phase-dependent behavior for selective oxidation of H₂S over MnO₂ catalysts. It was disclosed that the oxygen vacancy, reducibility and acid property of MnO₂ are essentially determined by the crystalline phase. Systematic experiments demonstrate that δ-MnO₂ is superior in active oxygen species, activation energy and H₂S adsorption capacity among the prepared catalysts. As a consequence, δ-MnO₂ nanosphere with a hierarchically porous structure shows high activity and stability with almost 100% H₂S conversion and sulfur selectivity at 210 °C, better than majority of reported Mn-based materials. Meanwhile, hierarchically porous structure of δ-MnO₂ nanosphere alleviates the generation of by-product SO₂ and sulfate, promoting the adoptability of Mn-based catalysts in industrial applications.

Keywords: Crystal phase; H(2)S selective oxidation; MnO(2) catalyst; Oxygen vacancy; Porous structure.