以介孔分子筛SBA-15为载体,采用浸渍法分别制备了Cu、Mn和CuMn(物质的量比为1∶1)的质量分数为5%~17%的Cu/SBA-15、Mn/SBA-15和CuMn/SBA-15催化剂,以及Ce质量分数为2.5%~7%、CuMn(物质的量比为1∶1)质量分数为12%的Ce/CuMn/SBA-15催化剂,在常压固定床反应器上评价了这些催化剂对甲苯催化燃烧的反应性能,用X-射线衍射、透射电镜、程度升温还原等分析手段对催化剂的结构进行了研究。活性评价结果表明,Cu质量分数大于12%时,Cu/SBA-15催化剂具有好的活性;Mn质量分数大于8%时,Mn/SBA-15催化剂具有好的活性;CuMn质量分数大于8%时,CuMn/SBA-15催化剂具有好的活性。并且相同Cu、Mn质量分数的双组分催化剂比单组分催化剂的活性要好,在Ce/CuMn/SBA-15催化剂中,Ce质量分数为2.5%~3.5%时,能提高催化剂的活性。结构研究表明,所有催化剂的SBA-15介孔结构仍然保持,并且Cu、Mn等活性组分都已分散在SBA-15分子筛的孔道中。在Ce/CuMn/SBA-15催化剂中,Ce质量分数小于5%时能促进CuMn的分散,并且提高了催化剂的氧化还原能力。
A series of Cu/SBA-15 (weight fraction 5% - 17% Cu), Mn/SBA-15 (5% - 17% Mn), CuMn/ SBA-15 (5% -17%CuMn) and Ce/CuMn/SBA-15 catalysts (2.5% -7% Ce, 12% CuMn) have been prepared. The activities of the materials in the catalytic combustion of toluene were evaluated in a continuous flow reactor at atmospheric pressure. The structures of the catalysts were investigated using XRD, TEM, and TPR. Cu/SBA-15 catalysts with above 12 % Cu, Mn/SBA-15 catalysts with above 8 % Mn, and CuMn/SBA-15 catalysts with above 8 % CuMn all showed good activity in the catalytic combustion of toluene. The activities of the catalysts containing both Cu and Mn were superior to those of the catalysts containing only Cu or Mn. In the case of CuMn/SBA-15 catalysts, addition of 2.5 % - 3.5 % Ce afforded an increase in the catalytic activity. The mesoporous structure of the SBA-15 precursor was retained in all of the catalysts with the active Cu, Mn, CuMn, and Ce components all confined in the SBA-15 mesopores. It was shown that Ce promoted dispersion of the CuMn species leading to an increased redox capability in the Ce/CuMn/SBA-15 catalysts.