论文部分内容阅读
用Mn_2O_3改性微球硅酸铝(SAMy,y为预载量)作载体,La_(1-x)Sr_xMnO_3催化剂CO氧化活性显著提高。Mn_2O_3除本身有一些CO氧化活性外,XRD结果表明主要是在SAMy载体上被载活性组分La_(1-x)Sr_xMnO_3氧化物相对含量和催化剂比表面有所提高,在所考察条件下,y=10为最佳。XPS研究表明:样品表面上的氧有吸附氧和晶格氧两种状态,Sr掺杂引起La_(1-x)Sr_xMnO_3化合物表面的锰以Mn~(3+)和Mn~(4+)价态并存,同时随x增加晶格氧空位增加,水热处理对500～650℃活性影响不大,而且14h后催化剂活性趋于稳定。使用热重仪研究了载体及催化剂在H_2气流及不同温度下的还原特性。
The oxidation activity of CO over La_ (1-x) Sr_xMnO_3 catalyst was significantly enhanced by Mn_2O_3 modified microspheres (SAMy, y is the pre-loading). In addition to some CO oxidation activity of Mn 2 O 3 itself, the XRD results show that the relative content of La 1-x Sr x MnO 3 oxide and the specific surface area of the catalyst are increased mainly on the SAMy support. Under the conditions investigated, y = 10 is the best. The results of XPS show that the oxygen on the surface of the sample is in the state of adsorbed oxygen and lattice oxygen. The Sr doping caused the Mn in the surface of La 1-x Sr x MnO 3 compounds to be Mn 3+ and Mn 4+ State coexist. Meanwhile, the lattice oxygen vacancies increase with increasing x. The hydrothermal treatment has little effect on the activity at 500-650 ℃, and the activity of the catalyst tends to be stable after 14h. The thermogravimetric method was used to study the reduction characteristics of carrier and catalyst under H 2 flow and different temperatures.