论文部分内容阅读
以NiCl_2·6H_2O为前驱体、(NH_4)_6Mo_7O_(24)·4H_2O和FeCl_3·6H_2O为助剂,通过浸渍、焙烧和NaBH_4还原制备高活性的NiMoFeB/γ-Al_2O_3催化剂。采用糠醛液相催化加氢为探针反应对其活性进行了评价。与NiMoB/γ-Al_2O_3相比,NiMoFeB/γ-Al_2O_3催化剂表现出更高的加氢活性和选择性,即使在较低温度60℃和5.0MPa条件下,加氢反应3.0h,糠醛转化率接近100%。考察Fe掺杂量和活性组分的负载顺序对催化剂活性的影响。结果表明,适宜的Fe掺杂量Mo+Ni与Fe原子比为20:1,Mo、Ni和Fe前驱体盐同时负载于γ-Al_2O_3时,催化剂活性最高。XRD研究表明,NiMoFeB/γ-Al_2O_3为无定形结构,活性组分在载体上分散均匀,具有良好的热稳定性。
Highly active NiMoFeB / γ-Al_2O_3 catalysts were prepared by impregnation, calcination and NaBH_4 reduction with NiCl_2 · 6H_2O as precursor, (NH_4) _6Mo_7O_ (24) · 4H_2O and FeCl_3 · 6H_2O as additives. The furfural liquid-phase catalytic hydrogenation was used as a probe reaction to evaluate its activity. Compared with NiMoB / γ-Al 2 O 3, the NiMoFeB / γ-Al 2 O 3 catalyst showed higher hydrogenation activity and selectivity. Even at the lower temperature of 60 ℃ and 5.0MPa, the hydrogenation reaction for 3.0h resulted in the close conversion of furfural 100%. The effects of Fe doping amount and loading order of active components on the catalyst activity were investigated. The results showed that the suitable Fe doping amount was 20: 1 for Mo + Ni and Fe, and the highest catalytic activity was obtained when Mo, Ni and Fe precursor salts were supported on γ-Al 2 O 3 simultaneously. XRD study shows that NiMoFeB / γ-Al 2 O 3 is an amorphous structure, and the active component is uniformly dispersed on the carrier and has good thermal stability.