NiMoB/γ-Al_2O_3催化剂制备及糠醛加氢活性评价

Preparation of NiMoB/γ-Al_2O_3 Catalyst and Its Activity Evaluation in Furfural Hydrogenation

以NiCl_2·6H_2O为前驱体,(NH_4)_6Mo_7O_(24)·4H_2O为改性剂,通过浸渍、焙烧和NaBH_4还原制备了高活性的NiMoB/γ-Al_2O_3催化剂。采用糠醛(FFR)液相催化加氢为探针反应评价了其反应活性。结果表明,与NiB、NiMoB相比,NiMoB/γ-Al_2O_3表现出很高的活性和选择性。在80℃和5.0 MPa下,甲醇溶液中加氢反应3.0 h,FFR转化率达99%,糠醇(FFA)的收率可达91%。考察了Mo掺量和NaBH_4还原前焙烧温度对催化剂活性的影响,确定了最佳的Mo/Ni物质的量比为1:7,焙烧温度为300℃。X射线衍射(XRD)和扫描电镜(SEM)表征表明。NiMoB/γ-Al_2O_3为无定型结构,活性组分在载体上分散均匀,且具有良好的热稳定性。

MoNiB/γ-Al2O3 amorphous alloy catalysts were prepared by NaBH4 reduction of NiCl2 · 6H2O and （NH4）6Mo7O24 · 4H2O supported on γ-Al2O3. Using liquid-phase hydrogenation of furfural （FFR） as a probe reaction, the activity of MoNiB/γ-Al2O3 was investigated. The results showed that γ-Al2O3 exhibited excellent activity and selectivity in comparison of NiB and NiMoB. After reaction for 3. 0 h at 80 ℃ and 5.0 MPa in methanol, FFR conversion could reach up to 99% with FFA yield of 91%. The effects of Mo-dopant and calcination pretreatment before NaBH4 reduction on the hydrogenation activity were investigated. The optimum Mo/Ni molar ratio and calcinations temperature were determined as 1 ： 7 and 300 ℃ respectively. X ray diffraction （XRD） characterization suggested that the catalyst possessed amorphous structure and scanning electron microscope （SEM） images showed NiMoB over the surface of γ-Al2O3 were highly dispersed on the support with high thermal stability.