Catalytic oxidation of toluene by manganese oxides:Effect of K^(+)doping on oxygen vacancy  

作　　者：Zhenzhen Huang Haiyang Li Xuejun Zhang Yanli Mao Yinghan Wu Wei Liu Hongrun Gao Mengru Zhang Zhongxian Song 

机构地区：[1]Faculty of Environmental and Municipal Engineering,Henan Key Laboratory of Water Pollution Control and Rehabilitation Technology,Henan University of Urban Construction,Pingdingshan 467036,China [2]College of Environmental and Safety Engineering,Shenyang University of Chemical Technology,Shenyang 110142,China

出　　处：《Journal of Environmental Sciences》2024年第8期43-56,共14页环境科学学报（英文版）

基　　金：supported by the National Natural Science Foundation of China(No.21872096);Scientific Research Project of Liaoning Provincial Department of Education(No.LJKMZ20220788);Zhongyuan Yingcai Jihua(No.ZYYCYU202012183);the Academic Leader of Henan Institute of Urban Construction(No.YCJXSJSDTR202204);the Doctoral Research Start-up Project of Henan University of Urban Construction(No.990/Q2017011)。

摘　　要：Alkali metal potassium was beneficial to the electronic regulation and structural stability of transition metal oxides.Herein,K ions were introduced into manganese oxides by different methods to improve the degradation efficiency of toluene.The results of activity experiments indicated that KMnO_(4)-HT(HT:Hydrothermal method)exhibited outstanding low-temperature catalytic activity,and 90%conversion of toluene can be achieved at 243℃,which was 41℃and 43℃lower than that of KNO_(3)-HT and Mn-HT,respectively.The largest specific surface area was observed on KMnO_(4)-HT,facilitating the adsorption of toluene.The formation of cryptomelane structure over KMnO_(4)-HT could contribute to higher content of Mn^(3+)and lattice oxygen(Olatt),excellent low-temperature reducibility,and high oxygen mobility,which could increase the catalytic performance.Furthermore,two distinct degradation pathways were inferred.PathwayⅠ(KMnO_(4)-HT):toluene→benzyl→benzoic acid→carbonate→CO_(2)and H2O;PathwayⅡ(Mn-HT):toluene→benzyl alcohol→benzoic acid→phenol→maleic anhydride→CO_(2)and H2O.Fewer intermediates were detected on KMnO_(4)-HT,indicating its stronger oxidation capacity of toluene,which was originated from the doping of K^(+)and the interaction between K-O-Mn.More intermediates were observed on Mn-HT,which can be attributed to the weaker oxidation ability of pure Mn.The results indicated that the doping of K^(+)can improve the catalytic oxidation capacity of toluene,resulting in promoted degradation of intermediates during the oxidation of toluene.

关 键 词：Catalytic oxidation Preparation method CRYPTOMELANE Mn^(3+)and lattice oxygen 

分 类 号：X701[环境科学与工程—环境工程]