Ni/TiO_2-Al_2O_3催化剂的制备及其在甘油水蒸汽重整制合成气中的应用

Preparation of Ni / TiO_2-Al_2O_3 Catalyst and Their Application in Glycerol Steam Refoming to Syngas

采用分步浸渍法制备了TiO2修饰和金属离子(M=Ce2+,La2+,Mn2+,Zr2+,Cd2+)掺杂的Ni基催化剂Catw Ni和Catw Ni/M,其结构和性能经XRD和H2-TPR表征。以甘油水蒸汽重整制合成气为探针反应,考察了TiO2修饰量(w),M,原料液配比r[V(甘油)∶V(水)]及时空速率(LHSV)对Catw Ni/M催化甘油重整反应性能的影响。结果表明:TiO2修饰可适当提高催化剂在甘油重整反应中的催化活性和合成气收率;Cat12Ni具有较佳的催化活性(甘油转化率80%)。M的掺杂是通过降低Ni与载体之间的相互作用以实现催化剂活性的提高(Cat12Ni/M可使甘油的转化率提高至94%以上);掺杂Ce和La可促进Catw Ni在重整反应过程的水气变换反应,而Mn和Cd的掺杂有利于合成气的生成。增加r和LHSV,可使甘油水蒸汽重整制合成气的收率得以提高,但不利于催化剂的稳定性能。

Ni /TiO 2-Al 2 O 3（ Catw Ni） and NiM/TiO 2-Al 2 O 3（ Catw Ni / M,M =Ce2＋,La3＋,Mn2＋,Zr2＋or Cd2＋） catalysts were prepared by fractional impregnation. The structures were characterized by XRD and H 2-TPR. Catalytic activities of the catalysts were investigated in preparation of syngas by steam reforming of glycerol. The effects of TiO 2 amount（ w）,introduced metal（ M） types,liquid reactants composition r[V（ glycerol） ∶ V（ water） ] and liquid hourly space velocity（ LHSV） on reforming were investigated in detail. The results indicated that TiO 2 modification could improve the catalytic property of Catw Ni in glycerol reforming,and Cat12 Ni exhibited a good catalytic activity with glycerol conversion of 80%. The introduction of other metal elements could weaken the strong metal-support interaction between Ni and support,leading to improvement on catalytic activity of catalysts（ glycerol conversion on Cat12 Ni / M reached up to 94%）. The presence of Ce and La could promote water-gas shift during refor-ming over Catw Ni. However,the introduced Mn and Cd species were helpful to syngas production. And at the same time,increasing of r and LHSV was able to improve syngas production,but was disadvantageous to catalytic stability of catalysts.