超声处理对Cu-Mn-Si/HZSM-5催化合成二甲醚的影响

Abstract

采用共沉积法、超声共沉积法制备Cu-Mn-SI/HzSM-5复合催化剂,并用bET、SEM、H2-TPr和XPS等手段进行了表征,考察超声处理方法对催化剂催化加氢性能的影响。结果表明,超声处理使催化剂颗粒的分散更为均匀,催化剂的比表面积增大,颗粒度更加细小。H2-TPr和XPS分析表明,经过超声处理后促进了Cu+的生成,增强了铜锰复合氧化物相互作用,有利于催化剂表面活性中心物种Cu+和Mn3+形成。Cu+和Mn3+可能共同构成了Cu-Mn-SI/HzSM-5催化剂的活性中心。

Cu-Mn-Si/HZSM-5 catalysts were prepared by co-precipitation method and co-precipitation method combining with supersonic vibration, and characterized by BET, SEM, H2-TPR and XPS to analyze the physical structure and catalytic performance of the catalysts.The results showed that ultrasonic treatment can make partical uniform and tiny, and increase the special surface area.H2-TPR and XPS results suggested that it can promote the creation of Cu+ on surface of catalyst and enhance the interaction of copper-manganese compound oxide, so that active specie Cu are difficult to be reduced by ultrasonic treatment.And ultrasonic treatment could make more Cu+ and Mn3+ formed, promote the interaction of Cu+ and Mn3+.Our study indicated that active centers in Cu-Mn-Si/HZSM-5 catalyst may be Cu+ and/or Mn3+ species.