溶胶-凝胶法制备丙烷脱氢Pt—Sn/Al_2O^3催化剂性能

Preparation of Pt-Sn/Al_2O_3 propane dehydrogenation catalysts by sol-gel method and their properties

采用溶胶-凝胶法和浸渍法制备了不同Sn组分含量的Pt-Sn/Al_2O_3催化剂,通过XPS、TEM和H_2吸附等物化表征手段对催化剂进行了表征,考察了无H_2存在下的催化剂丙烷脱氢性能。结果表明,采用溶胶-凝胶法导致-部分sn组分被包埋,减少高温还原条件下Sn组分的析出而提高催化脱氢活性。在550℃反应6.5h的条件下,丙烯收率36.3%,丙烯选择性达98.8%。

Pt-Sn/Al2O3 catalysts with different loadings of Sn were prepared by sol-gel and impregnation method and characterized by TEM, H2-adsorption and XPS. Properties of the catalysts for dehydrogenation of propane were investigated under severe condition, i. e. , high temperature （550 ℃ ） and in the absence of H2. It was found that sol-gel method led to encapsulation of Sn in the support structure and avoidedprecipitation during reduction and thus enhanced the catalytic activity. Propylene yield of 36.3% and selectivity to propylene of 98.8% were obtained over the catalyst under 550 ℃ and 6.5 h.