Title

Insights into the pollutant electron property inducing the transformation of peroxymonosulfate activation mechanisms on manganese dioxide

Publication Name

Applied Catalysis B: Environmental

Abstract

Herein, using manganese dioxide octahedral molecular sieve (Mn-OMS) as the catalyst, we investigate how pollutant electron property affects the peroxymonosulfate (PMS) activation mechanism. More than 95% of electron-rich pollutants are degraded in the Mn-OMS/PMS system after 30 min reaction time, but oxidative decomposition of electron-poor pollutants takes at least 150 min. This difference in reaction rate is proved to be pollutant-dependent. We then combine multiple methods to cross-validate the PMS activation mechanism, including the quenching test, EPR characterization, solvent-exchange experiment, PMS decomposition rate test, and electrochemical analysis. Catalyst-mediated electron transfer is determined as the main activation mechanism for electron-rich pollutants degradation, while removal of electron-poor pollutants relies on singlet oxygen (1O2) and/or radicals. Additionally, the PMS activation mechanism depends on whether H2O or pollutants or low-valence Mn ions preferentially transfer electrons to the adsorbed PMS. This work provides mechanistic insights into the effect of pollutants type on PMS activation.

Open Access Status

This publication is not available as open access

Volume

317

Article Number

121753

Funding Number

201804010398

Funding Sponsor

National Natural Science Foundation of China

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Link to publisher version (DOI)

http://dx.doi.org/10.1016/j.apcatb.2022.121753