Al2O3 supported catalysts of different particle sizes (10,20,30 nm) and Cu/ SMA(a)(a = 10,20,30) supported by nano-scalealumina were prepared by means of loading, and their catalytic efficiency was tested. The results show that the order of methane catalyticreduction of NO and methane catalytic oxidation efficiency is Cu/ SMA(20) > Cu/ SMA(10) > Cu/ SMA(30) > Cu/ Al2O3. Cu/ SMA(20) methanehas the best catalytic capacity to reduce NO. The physical and chemical properties of the catalyst were further analyzed by TEM, BET,XPS and NH3-TPD. The TEM test results show that small particles of nano-sized alumina as catalyst carrier could disperse copper oxideas active component better, which is conducive to enhancing the catalytic activity of the catalyst. The results of XPS and NH3-TPD showthat Cu/ SMA(a)(a= 10,20,30) catalyst has more oxygen vacancies and acidic sites than Cu/ Al2O3 catalyst. Moreover, the catalyst contains a well-developed pore structure, which provides more contact sites for the REDOX reaction of methane under the action of the catalyst, and the catalyst contains a higher vacancy oxygen Oβ, which increases the denitrification efficiency of the catalyst. The reaction mechanism was further analyzed by H2-TPR and TR-FI. The Cu2+ species in the catalyst are more likely to be reduced to Cu+ in thereaction, and Cu+ plays a synergistic role in the subsequent denitration reaction and promotes the catalytic reduction of NO in methane. NOfirst reacts with O2 to form an intermediate substance. CH4 then undergoes a REDOX reaction to form N2.

陈晨(1998—),女,内蒙古自治区巴彦淖尔人,硕士研究生。E-mail:nmgchenchen@163.com

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CHEN Chen,AN Donghai,SONG Jialin,et al.Characteristics and mechanism of methane redox NOx by catalysts with different carrier particle sizes[J].Clean Coal Technology,2023,29(11):25-34.