School of Energy and Power Engineering,Shandong University
Changji University

通过负载的方式制备了不同粒径(10、20、30nm)Al2O3载体的催化剂,纳米级氧化铝为载体的Cu/SMA(a)(a=10,20,30)催化剂并测试了其催化效率,结果表明催化剂的甲烷催化还原NO及甲烷催化氧化效率顺序均为Cu/SMA(20)>Cu/SMA(10)>Cu/SMA(30)>Cu/Al2O3催化剂。Cu/SMA(20)甲烷催化还原NO的能力最优。进一步通过TEM、BET、XPS及NH3-TPD对催化剂的物理化学性质进行分析,TEM测试结果表明小颗粒纳米级氧化铝作为催化剂载体可更好分散作为活性组分的氧化铜,有利于增强催化剂的催化活性;XPS及NH3-TPD测试结果表明Cu/SMA(a)(a=10,20,30)催化剂相比于Cu/Al2O3催化剂拥有更多氧空位及酸性位点;且该催化剂含有发达的孔隙结构,为甲烷在催化剂作用下发生的氧化还原反应提供了更多的接触位点,同时催化剂含有较高的空位氧Oβ,增加了催化剂脱硝效率。进一步通过H2-TPR和TR-FI对反应机理进行分析,催化剂中的Cu2+物种在反应中更易被还原为Cu+,Cu+在接下来的脱硝反应中起协同作用,对甲烷催化还原NO具有促进作用,NO先与O2发生反应生成了中间态物质,随后CH4发生氧化还原反应而生成N2。

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.

山东省重点研发计划(重大科技创新工程)资助项目(2020CXGC011402);山东省自然科学基金资助项目(ZR2020ME190)

陈晨,安东海,宋佳霖,等.不同载体粒径的催化剂对甲烷氧化还原 NOx特性及机理[J].洁净煤技术,2023,29(11):25-34.

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.