助剂对Ni/Al_2O_3催化剂芳烃加氢热稳定性和抗硫性能的影响

Effects of promoters on thermal stability and sulfur tolerance of nickel-based aromatic hydrogenation catalysts

考察了助剂Mg、La、Mo、Ti和Th的加入对Ni/Al2O3催化剂芳烃加氢热稳定性和抗硫性能的影响。结果表明,除Mo以外,其他少量助剂的加入均有助于催化剂活性的提高,其中以Mg效果最好。Mg的加入使Ni原子的电子云密度升高,提高了活性组分Ni的分散度,从而提高了催化剂的催化活性和使用寿命;Mo对催化剂的加氢活性和抗硫性能没有帮助,可能是由于没有形成作为主要抗硫相的钼酸镍或钼镍合金。

Ni/Al2O3 catalysts were modified by Mg,La,Mo,Ti and Th. Thermal stability and tolerance to sulfur poisoning was investigated via hydrogenation of toluene containing thiophene. It was shown that the catalytic activity were enhanced by incorporation of Mg,La,Ti and Th, except Mo. The catalyst containing Mg exhibited the best behaviors. Mg addition of enhanced the activity, sulfur tolerance and thermal stability by increasing electronic cloud density of the nickel atoms and improving dispersity of nickel.