摘要
以常规浸渍法制备了一系列Pd基催化剂,考察载体结构、织构及组成对其加氢性能的影响。采用程序升温技术(TPR-H2、TPD-CO)对催化剂进行了表征和相应分析。结果表明,Al2O3载体中以高温1100℃焙烧后形成的δ晶型具有更高的乙烯选择性。Pd基催化剂的Al2O3载体预先修饰MgO或CeO2后,能获得良好的金属分散度和适宜的反应物的吸附及产物的脱附特性,使得在高氢/炔体积比下催化剂样品上乙烯收率也维持在80%左右。在非Al2O3型载体制备的催化剂中,与金属Pd存在强相互作用的TiO2载体制备的催化剂的催化性能优越,最优样的乙烯收率达到95%。催化剂表面的PdbHx物种和Pd-C结合能在很大程度上影响着H2吸附活化和乙烯脱附能力,这对选择加氢性能有至关重要的作用。
Supported palladium catalysts were elaborated by impregnation method, in an attempt to determine the influences of support pretreatment and species on the activity and the selectivity of acetylene hydrogenation. Among tested Al2O3 supports, δ-Al2O3 formed under 1100℃ calcination possessed more selectivity of C2H4. The MgO or CeO2 modified Al2O3 resulted in the good catalytic performances of catalyst, and the ethylene yield kept about 80 % at high volune ratio of H2 to C2H2. In addition, because of the strong palladium-support interaction and the suitable adsorption-desorption properties for reactant and products, the hydrogenation performance of Pd/TiO2 catalyst was improved much significantly, and the ethylene yield was enhanced to the value of 95 %. From the temperature programmed reduction （TPR）and the carbon monoxide desorption （TPR CO） data, it is indicated that Pd^bHx species on catalyst surface and Pd-C bond strength influenced strongly H2 adsorption and the ethylene desorption from the catalyst surface.
出处
《石油学报（石油加工）》
EI
CAS
CSCD
北大核心
2006年第2期20-26,共7页
Acta Petrolei Sinica(Petroleum Processing Section)
基金
国家自然科学基金(29903011和20590360)资助项目
