新型高性能Cu/HMS催化剂的合成及其在草酸二甲酯催化加氢合成乙二醇反应中的应用

Novel Highly Efficient Cu/HMS Catalyst and Its Application to the Hydrogenation of Dimethyl Oxalate to Ethylene Glycol

采用原位合成法合成了介孔Cu/HMS催化剂,并以草酸二甲酯催化加氢合成乙二醇为探针反应考察了不同焙烧温度对反应催化性能的影响,结果表明焙烧温度为650℃时合成的催化剂在该反应中表现出最佳的催化性能.在反应温度为200℃、压力为3MPa、氢酯比为50、液时空速为0.74h-1的条件下,草酸二甲酯的转化率达到100%,并且乙二醇的选择性达到97%.采用X射线粉末衍射、N2低温吸附、H2-TPR、N2O滴定、X射线光电子能谱及傅利叶变换红外光谱对系列催化剂进行了系统表征,阐述了焙烧温度对催化性能影响的本质原因.研究表明焙烧温度能够影响活性铜物种的分散度和铜物种与载体间的相互作用,从而影响草酸二甲酯催化加氢的催化性能.

A series of mesoporous Cu-HMS catalysts prepared under different calcination temperatures were synthesized by a deposition precipitation method. The catalytic reaction was tested via the hydrogena- tion of dimethyl oxalate （DMO） to ethylene glycol （EG）. The 100% DMO conversion and 97% EG selectiv- ity could be obtained over the optimized catalyst calcined at 650 ℃. XRD, BET, H2-TPR, N20 titration and XPS were used to unveil the intrinsic essence of the catalyst. It was suggested that the dispersion of copper species and the interaction between the copper species and the silica be closely related to the calcination temperature and play a crucial role in the hydrogenation of DMO to EG.