摘要
以MCM-41介孔分子筛为载体,通过浸渍法和研磨法制备了Cu/MCM-41和Cu-ZnO/MCM-41催化剂。采用XRD、N2吸附-脱附、TPR、NH3-TPD等方法对催化剂进行表征。结果表明,催化剂均保留了MCM-41有序的六方介孔结构,ZnO和CuO存在着相互作用,研磨法制备的催化剂其酸性比浸渍法制备的略强。在连续流动式常压微型反应器上评价了催化剂对甲醇脱氢制甲酸甲酯反应的催化活性。浸渍法和研磨法相比,浸渍法制备的催化剂对甲酸甲酯的选择性较高,但对甲醇的转化率较低;研磨法制备的催化剂对甲酸甲酯的选择性较低,但甲醇的转化率较高,添加助剂ZnO能提高甲酸甲酯的选择性。浸渍法制备的Cu-ZnO/MCM-41-I在250℃对甲醇的转化率和对甲酸甲酯的选择性分别为15.28%和81.31%,在相同条件下,研磨法制备的Cu-ZnO/MCM-41-G对甲醇的转化率和对甲酸甲酯的选择性分别为18.83%和75.32%。
Cu--ZnO/MCM--41 and Cu/MCM--41 catalysts were prepared using impregnation and grind- ing methods with MCM--41 molecular sieves as the support. The catalysts were characterized by XRD, N2 adsorption--desorption, TPR and NH3--TPD methods. The results showed that the catalysts retain the ordered mesoporous hexagonal structure of MCM--41, and that there was interaction between ZnO and CuO in the catalysts and the catalysts prepared by grinding had slightly stronger acidity than the catalysts prepared by impregnation. The catalytic activity of the dehydrogenation of methanol to methyl formate （MF） was evaluated using the flow microreactor under atmospheric pressure. The catalyst prepared by impregnation has a better selectivity for the MF, but a lower methanol conversion rate than the catalyst prepared by grinding. The MF selectivity could be improved by ZnO additive while the methanol conversion rate was reduced. For Cu/MCM--41 prepared by impregnation and grinding, the methanol conversion was 20. 18% and 24. 13% respectively and the MF selectivity was 73. 75% and 67.35M at 250℃ respectively. Likewise for Cu--ZnO/MCM--41 prepared by impregnation and grinding, the methanol conversion rate was 15.28% and 18. 83% respectively and the MF selectivity was 81.31% and 75.32% at 250℃ respectively.
出处
《常州大学学报（自然科学版）》
CAS
2012年第2期22-27,共6页
Journal of Changzhou University：Natural Science Edition
基金
江苏省高校自然科学基金(08KJD150013)
关键词
MCM-41载体
铜基催化剂
浸渍法和研磨法
甲醇脱氢
甲酸甲酯
MCM--41 support
Cu-- based catalysts
impregnation and grinding methods
dehydrogenation of methanol
methyl formate
