锰铈复合氧化物催化氧化甲苯与乙酸乙酯的转化速率差异研究  

Study on the Conversion Rate Differences Between Toluene and Ethyl Acetate Catalytic Oxidation via MnOx-CeO2 Mixed Oxides

作　　者：蒋翌文 高景恒 JIANG Yiwen;GAO Jingheng(Guangdong Industry Polytechnic University,Guangzhou 510300,China;Guangzhou Research Institute of Environmental Protection Co.,Ltd.,Guangzhou 510620,China)

机构地区：[1]广东轻工职业技术大学,广东广州510300 [2]广州市环境保护科学研究院有限公司,广东广州510620

出　　处：《生物化工》2024年第6期110-113,121,共5页Biological Chemical Engineering

摘　　要：目的:探究锰铈复合氧化物催化降解甲苯和乙酸乙酯的反应速率差异及其机理。方法:采用程序升温氧化法表征甲苯和乙酸乙酯在空间速率为10000 mL/(g·h)时的催化转化率,通过计算得到催化剂活性和反应速率;采用原位拉曼光谱表征甲苯和乙酸乙酯反应中催化剂的表面氧空位浓度,并计算单位氧空位转化速率。结果:在1600 mg/m^(3)和2800 mg/m^(3)浓度下,乙酸乙酯的完全转化温度分别为210℃和220℃,较甲苯低20℃;在低温时,乙酸乙酯的反应速率更高,温度升高后两者接近;甲苯和乙酸乙酯在起燃阶段的单位氧空位转化速率近乎相同。结论:氧空位主导的气相氧活化过程对反应速率无直接影响,反应速率的差异可归因于催化剂表面活性位点对不同反应物官能团降解速率的差异。Objective:To investigate the differences in reaction rates and the mechanism of the catalytic degradation of toluene and ethyl acetate via MnOx-CeO2 mixed oxides.Methods:The catalytic conversion of toluene and ethyl acetate are characterized by temperature programmed oxidation at an air velocity of 10000 mL/(g·h).The catalytic activities and the reaction rates are obtained by calculations;the surface oxygen vacancies concentration of the catalysts in the reaction of toluene and ethyl acetate is characterized by in-situ Raman spectroscopy,and the conversion rate of the unit oxygen vacancy(CRPOV)is calculated.Results:At the concentrations of 1600 mg/m^(3) and 2800 mg/m^(3),the complete conversion temperatures of ethyl acetate are 210℃and 220℃,respectively,which are 20℃lower than that of toluene;the reaction rates of ethyl acetate are higher at low temperatures,and are close to those of toluene at elevated temperatures;the CRPOV of toluene and ethyl acetate are nearly the same in the ignition stage.Conclusions:The gas-phase oxygen activation process dominated by oxygen vacancies has no direct effect on the reaction rates,and the differences in the reaction rates can be attributed to the differences in the degradation rates of different reactants’functional groups over catalyst surface active site.

关 键 词：锰铈复合氧化物 甲苯 乙酸乙酯 催化氧化 

分 类 号：X511[环境科学与工程—环境工程]