Mangenese oxides were synthesized using two new methods,a novel solvent‐free reaction and a reflux technique,that produced cryptomelane‐type products(K‐OMS‐2).Oxides were also synthesized using conventional method...Mangenese oxides were synthesized using two new methods,a novel solvent‐free reaction and a reflux technique,that produced cryptomelane‐type products(K‐OMS‐2).Oxides were also synthesized using conventional methods and all specimens were applied to the oxidation of ethyl acetate and butyl acetate,acting as models for the volatile organic compounds found in industrial emissions.The catalysts were also characterized using N2adsorption,X‐ray diffraction,scanning electron microscopy,temperature programmed reduction and X‐ray photoelectron spectroscopy.Each of the manganese oxides was found to be very active during the oxidation of both esters to CO2,and the synthesis methodology evidently had a significant impact on catalytic performance.The K‐OMS‐2nanorods synthesized by the solvent‐free method showed higher activity than K‐OMS‐2materials prepared by the reflux technique,and samples with cryptomelane were more active than those prepared by the conventional methods.The catalyst with the highest performance also exhibited good stability and allowed90%conversion of ethyl and butyl acetate to CO2at213and202°C,respectively.Significant differences in the catalyst performance were observed,clearly indicating that K‐OMS‐2nanorods prepared by the solvent‐free reaction were better catalysts for the selected VOC oxidations than the mixtures of manganese oxides traditionally obtained with conventional synthesis methods.The superior performance of the K‐OMS‐2catalysts might be related to the increased average oxidation state of the manganese in these structures.Significant correlations between the catalytic performance and the surface chemical properties were also identified,hig-hlighting the K‐OMS‐2properties associated with the enhanced catalytic performance of the materials.?2018,Dalian Institute of Chemical Physics,Chinese Academy of Sciences.Published by Elsevier B.V.All rights reserved.展开更多
基金This work was supported by project “AIProcMat@N2020‐Advanced Industrial Processes and Materials for a Sustainable Northern Region of Portugal 2020”, with the reference NORTE‐01‐0145‐FEDER‐000006, supported by Norte Portugal Regional Operational Programme
文摘Mangenese oxides were synthesized using two new methods,a novel solvent‐free reaction and a reflux technique,that produced cryptomelane‐type products(K‐OMS‐2).Oxides were also synthesized using conventional methods and all specimens were applied to the oxidation of ethyl acetate and butyl acetate,acting as models for the volatile organic compounds found in industrial emissions.The catalysts were also characterized using N2adsorption,X‐ray diffraction,scanning electron microscopy,temperature programmed reduction and X‐ray photoelectron spectroscopy.Each of the manganese oxides was found to be very active during the oxidation of both esters to CO2,and the synthesis methodology evidently had a significant impact on catalytic performance.The K‐OMS‐2nanorods synthesized by the solvent‐free method showed higher activity than K‐OMS‐2materials prepared by the reflux technique,and samples with cryptomelane were more active than those prepared by the conventional methods.The catalyst with the highest performance also exhibited good stability and allowed90%conversion of ethyl and butyl acetate to CO2at213and202°C,respectively.Significant differences in the catalyst performance were observed,clearly indicating that K‐OMS‐2nanorods prepared by the solvent‐free reaction were better catalysts for the selected VOC oxidations than the mixtures of manganese oxides traditionally obtained with conventional synthesis methods.The superior performance of the K‐OMS‐2catalysts might be related to the increased average oxidation state of the manganese in these structures.Significant correlations between the catalytic performance and the surface chemical properties were also identified,hig-hlighting the K‐OMS‐2properties associated with the enhanced catalytic performance of the materials.?2018,Dalian Institute of Chemical Physics,Chinese Academy of Sciences.Published by Elsevier B.V.All rights reserved.
