Catalytic mechanism study on manganese oxide in the catalytic supercritical water oxidation of nitrobenzene

Abstract

MnO2 and Mn2O3 transform into each other, and the mixture acts as an electron relay to promote the generation of strong oxidizing agents and the catalytic oxidation of nitrobenzene during catalytic supercritical water oxidation.

Fabrication of manganese dioxide/carbon/attapulgite composites derived from spent bleaching earth for adsorption of Pb(ii) and Brilliant green

“…[9][10][11] MnO 2 is of considerable importance in technological applications, including ionexchange, molecular adsorption, catalysis, and electrochemical supercapacitors owing to their outstanding structural exibility combined with novel chemical and physical properties. [12][13][14][15] In particular, the MnO 2 -based adsorbents have attracted intensive interest owing to their high natural abundance, high specic surface area, environmental compatibility, abundant surface functional groups and strong affinities for some organic dyes and heavy metal ions such as methylene blue, Congo red, Cu(II), Pb(II), Cd(II), Zn(II), As(V) and Cr(VI). [16][17][18][19] In general, based on redox reactions between Mn 2+ and MnO 4 À , MnO 2 have been successfully fabricated by a variety of chemical routes, including sol-gel, thermal decomposition, hydrothermal method and solid state reaction.…”

Functional Materials for Waste-to-Energy Processes in Supercritical Water

“…MnO 2 , prepared by compression molding with nitrocellulose as pore forming agent and calcinated afterwards, it was catalytically tested for the oxidation of nitrobenzene at 738 K, 280 bar. Under these conditions, the degradation efficiency was higher than 99% even after 18 h on stream, showing the stability of the catalyst in SCW [134]. Using bulk MnO 2 catalyst and H 2 O 2 as oxidant, experiments on the oxidation of diluted coke-works waste, containing manly NH 3 and phenol, were performed at 773 K and 247 bar.…”

“…Most of the experiments on the oxidative catalysis in SCW are performed starting from model solutions and using MnO 2 -based catalysts [25,98,108,130,134].…”

Review on Mechanisms and Kinetics for Supercritical Water Oxidation Processes

“…Catalyzed oxidation: some scholars thought that catalysts produced activated oxygen, such as O − 2 , O and O 2− , to promote the removal of organics in the SCWO process [170,171]. However, the DCKMs and detailed kinetic descriptions are still in shortage since the heterogeneous reactions between catalysts and reactants increase the model complexity.…”