载体酸碱性对镍基催化剂催化甘油水蒸汽重整制氢影响

Effect of acid-base properties of supports on catalytic performance of nickel catalysts for glycerol steam reforming

采用等体积浸渍法制备了以Al2O3,SiO2,ZnO,MgO,白云石(CaMg[CO3]2)等具有不同酸碱性质氧化物作为载体的负载型镍基催化剂.在固定床反应装置中考察了上述催化剂的甘油水蒸汽重整制氢的催化性能.结果表明:在常压、反应温度350～500℃条件下,载体酸碱性对镍基催化剂甘油水蒸汽重整制氢的催化性能影响很大.相比负载于酸性氧化物载体的镍基催化剂(Ni/Al2O3,Ni/SiO2),负载于碱性氧化物载体的镍基催化剂(Ni/白云石,Ni/MgO)能够获得更高的甘油转化率以及氢气选择性,在450℃时甘油转化率与氢气选择性可分别达到100%和84%.这表明以碱性氧化物作为负载镍催化剂载体时,镍基催化剂对甘油水蒸汽催化重整制氢反应有较好的催化性能.

Nickel catalysts with different supports： Ni/Al2O3, Ni/SiO2, Ni/ZnO, Ni/MgO, Ni/ dolomite, were prepared by incipient impregnation method. The performance of these catalysts on the glycerol stream reforming for hydrogen has been studied in a fixed-bed reactor. The results indicate that the catalytic performance of these catalysts significantly depends on the acid-base properties of the supports. The catalysts with base oxide supports （Ni/dolomite, Ni/MgO） give a much higher selectivity of hydrogen and conversion of the glycerol than those with acid oxide supports （Ni/SiO2, Ni/Al2O3） under atmosphere pressure and 350-500 ℃. For Ni/dolomite, the conversion of glycerol and the selectivity of hydrogen are 100% and 84%, respectively, at 450 ℃. The nickel catalysts with base supports are advantageous over those on acid supports in glycerol stream reforming for hydrogen.