摘要
采用逐层负载-孔道内氨/水蒸气原位羟化法制备了高负载量的LaMnOx/SBA-15催化剂,并采用X射线衍射、N2吸附-脱附和程序升温还原等技术对催化剂进行了表征,考察了其催化甲苯燃烧的性能.结果表明,孔道内氨/水蒸气原位羟化提高了LaMnOx活性物种在SBA-15孔道内的分散度和还原性,显著改善了高负载量的LaMnOx/SBA-15催化剂的活性.在空速5000h–1的条件下,温度升至205oC时甲苯转化率即可达50%,较之普通浸渍法制得的催化剂上甲苯达到该转化率所需温度降低了约105oC.实验得到LaMnOx/SBA-15的适宜原位羟化处理温度为60oC,处理时间40min.
A highly loaded LaMnOx/SBA-15 catalyst（60%） was prepared by step coating NH3/water vapor-induced internal hydrolysis（VIH） and characterized by X-ray diffraction,N2 adsorption-desorption,and temperature-programmed reduction（H2-TPR） . Its catalytic per-formance for toluene combustion was also evaluated. The results showed that the VIH process clearly improved the activity of the LaM-nOx/SBA-15 catalyst. Using a toluene concentration of 0.86% and a GHSV of 5000 h–1,a 50% toluene conversion was obtained at 205 °C for the LaMnOx/SBA-15 sample prepared by the VIH process. This temperature was 105 °C lower than that for the sample prepared by conven-tional impregnation. N2 adsorption-desorption and H2-TPR revealed that the VIH process improved the distribution of the LaMnOx active phase in the pores of SBA-15 and improved its reduction properties. The optimal VIH conditions were a temperature of 60 °C and a reaction time of 40 min.
出处
《催化学报》
SCIE
EI
CAS
CSCD
北大核心
2011年第2期250-257,共8页
基金
国家自然科学基金(20903080)
关键词
高负载量
镧
锰
复合氧化物
SBA-15
原位羟化
催化燃烧
甲苯
highly loaded
lanthanum
manganese
composite oxide
SBA-15
vapor-induced internal hydrolysis
catalytic combustion
toluene
