过渡金属对Au-Pd/TiO_2-Al_2O_3催化剂加氢脱硫性能的影响

研究了掺杂过渡金属Ru,Ni,Co对Au-Pd/TiO2-Al2O3催化剂催化噻吩加氢脱硫活性的影响,并采用X射线衍射、电感耦合等离子发射光谱、程序升温还原和程序升温脱附等方法对TiO2-Al2O3复合载体、Au-Pd/TiO2-Al2O3和Au-Pd-TM/TiO2-Al2O3(TM表示过渡金属)催化剂进行了表征。实验结果表明,掺杂过渡金属未改变Au-Pd/TiO2-Al2O3催化剂的结构;掺杂Ru或Ni增强了Au-Pd/TiO2-Al2O3催化剂的活性组分与TiO2-Al2O3复合载体的相互作用,降低了反应活化能,提高了催化剂活性组分的分散度和活性比表面积,改善了Au-Pd/TiO2-Al2O催化剂的吸附性能,从而提高了Au-Pd/TiO2-Al2O3催化剂催化噻吩加氢脱硫的活性;而掺杂Co的效果则与之相反。

Effects of Doping Transition Metals on Activity of Au-Pd/TiO2-Al2O3 Catalyst in Hydrodesulfurization

Effects of doping transition metals(Ru,Ni and Co)on activity of Au-Pd/TiO2-Al2O3 catalyst in thiophene hydrodesulfurization were studied.The catalysts were characterized by means of XRD,TPR and TPD.Doping of transition metals to Au-Pd/TiO2-Al2O3 catalyst does not change its structure.The presence of doped Ru or Ni can reinforce interaction of active constituents with TiO2-Al2O3 composite support,enlarge active specific surface area,enhance dispersion of active constituents,lower activation energy of thiophene hydrodesulfurization,and improve adsorptive behavior of catalysts.So the catalyst becomes more active.But for doping of Co to Au-Pd/TiO2-Al2O3 catalyst,the effect for hydrodesulfurization is negative.