W-Mn/SBA-15/FeCrAl催化剂制备及其甲烷氧化偶联反应性能

Preparation of W-Mn/SBA-15/FeCrAl Catalysts and Catalytical Performance of Oxidative Coupled Reaction of Methane

以介孔分子筛SBA-15为载体,Na2WO4、Mn和Ce为活性组分,采用浸渍法制备了一系列Ce-W-Mn/SBA-15催化剂,然后以FeCrAl合金薄片为基体,Ce-W-Mn/SBA-15催化剂为浆料,采用涂覆法制备了一系列Ce-W-Mn/SBA-15/FeCrAl金属基整体式催化剂。在微型固定床反应器中对催化剂的甲烷氧化偶联反应性能进行了评价,考察了反应条件对催化性能的影响,采用XRD对催化剂的结构进行了表征。结果表明,W-Mn/SBA-15催化剂具有较好的甲烷氧化偶联反应性能,而Ce-W-Mn/SBA-15/FeCrAl金属基整体式催化剂除发生甲烷氧化偶联反应以外,还伴随明显的甲烷部分氧化反应,其中3%Ce-5%Na2WO4-2%Mn/SBA-15/FeCrAl催化剂的活性相对较好,其甲烷转化率为28.9%,C2烃选择性为22.0%,CO的选择性为60.3%,H2的选择性为21.6%。XRD结果显示,Ce-W-Mn/SBA-15/FeCrAl金属基整体式催化剂存在α-方石英、CeO2、Na2WO4、Mn2O3等物相。

A series of Ce-W-Mn/SBA-15 catalysts are prepared by immersion method using Na_2WO_4,Mn and Ce as active contents and molecular sieve SBA-15 as support. Then Ce-Na_2WO_4-Mn /SBA-15/Al2O3/FeCrAl metallic monolithic catalysts are prepared by coating method using FeCrAl alloying thin sections as support, and Ce-Na_2WO_4-Mn/SBA-15 catalysts as sizing agent. The catalytical performance of oxidative coupled reaction of methane is evaluated in a mini fixed bed reactor. The effects of reactive condition on catalytical performance are investigated. The structure of the catalysts was characterized using XRD. The results indicate that W-Mn/SBA-15 catalysts have a good catalytical performance for the oxidative coupled reaction of methane. The partial oxidation reaction of methane may occur with oxidative coupled reaction of methane when using the Ce-W-Mn/SBA-15/FeCrAl metallic monolithic catalysts. 3%Ce-5% Na_2WO_4-2%Mn/SBA-15/FeCrAl catalysts show the better activity, whose methane conversion, C2 selectivity, CO selectivity and H2 selectivity are 28.9%, 22.0%, 60.3% and 21.6% respectively. The XRD results indicate that in the Ce-W-Mn/SBA-15/FeCrAl metallic monolithic catalysts, there are several phases, such as α-cristobalite,CeO2, Na_2WO_4, and Mn2O3.