fulltext.study @t Gmail

Occurrence of radical and nonradical pathways from carbocatalysts for aqueous and nonaqueous catalytic oxidation

Paper ID Volume ID Publish Year Pages File Format Full-Text
45002 46393 2016 8 PDF Available
Title
Occurrence of radical and nonradical pathways from carbocatalysts for aqueous and nonaqueous catalytic oxidation
Abstract

•Nanostructured carbons were investigated for peroxymonosulfate (PMS) activation.•Density functional theory (DFT) were employed to explore the PMS activation.•Radical and nonradical oxidations could occur on different carbocatalysts.•The nonradical oxidation on carbon is superior to the radical oxidation.

Metal-free activation of superoxides provides an efficient and environmentally benign strategy for heterogeneous catalytic oxidation. In this study, nanocarbons with varying carbon-conjugation structures and functional groups were investigated for peroxymonosulfate (PMS) activation. It was discovered that radical and nonradical oxidations could occur on different carbocatalysts depending on the carbon structure. Radical oxidation occurs exclusively on MWCNTs and CMK-3, similar to a metal oxide, MnO2. Both radical and nonradical oxidations are very pronounced in nanodiamond (AND-900)/PMS whilst nonradical oxidation is dominated in reduced graphene oxide (rGO-900)/PMS. Density functional theory (DFT) calculations were employed to explore the PMS adsorption and OO bond activation on the different carbon configurations for an in-depth probe of the activation mechanism. The intact sp2-conjugated π system in MWCNTs and electron-rich ketonic groups (as Lewis basic sites) in CMK-3 can stimulate PMS dissociation to generate SO4− and OH, similar to metal-based catalysts. However, the defective edges at the boundary of carbon network are able to facilitate the organic degradation without generation of the reactive radicals, which is well supported by both experiments and the DFT calculation. The emerging nonradical oxidation induced by the carbocatalysis is superior to the radical oxidation on most metal oxides for effective degradation of various organics. The influences of solution pH, various anions (H2PO42−, HCO3− and Cl−) and background organic matters (humic acid) on the nonradical oxidation were further evaluated. The nonradical oxidation on carbocatalysts can be utilized as a green and effective oxidation strategy for aqueous environmental remediation and nonaqueous phase oxidation.

Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slide

Keywords
Nonradical oxidation; Radical scavenger; Peroxymonosulfate activation; DFT; Carbocatalysis
First Page Preview
Occurrence of radical and nonradical pathways from carbocatalysts for aqueous and nonaqueous catalytic oxidation
Get Full-Text Now
Don't Miss Today's Special Offer
Price was $35.95
You save - $31
Price after discount Only $4.95
100% Money Back Guarantee
Full-text PDF Download
Online Support
Any Questions? feel free to contact us
Publisher
Database: Elsevier - ScienceDirect
Journal: Applied Catalysis B: Environmental - Volume 188, 5 July 2016, Pages 98–105
Authors
, , , , , ,
Subjects
Physical Sciences and Engineering Chemical Engineering Catalysis
Get Full-Text Now
Don't Miss Today's Special Offer
Price was $35.95
You save - $31
Price after discount Only $4.95
100% Money Back Guarantee
Full-text PDF Download
Online Support
Any Questions? feel free to contact us