| In this paper, the effects of different supports and Mo on the catalytic properties of the amorphous Ni-B alloy are studied, and the liquid phase hydrogenation of furfural to furfural alcohol is selected as probe reaction. The composition of the alloys is analyzed by ICP, the thermal stability of the samples studied by DSC, and the morphology of the alloy particles is observed by TEM. The adsorption and desorption properties of the catalysts are characterized by TPD and TPR, respectively. The specific surface area and the distribution of the pore radius are examined by N2 adsorption method.The effects of Ni content on the catalytic properties of Ni-B/Y-Al2O3 and Ni-B/TiO2-Al2O3 are studied. The results show that the catalysts of 30% Ni content compared with that of the support exhibit the best catalytic properties for furfural hydrogenation to furfural alcohol. The proper reaction time is 6h under the temperature from 353K to 433K. The best composition of the composite support Al2O3-TiO2 is Al2O3:TiO2=1:1(weight ratio). The results also indicate that the supported Ni-B-Mo amorphous alloys exhibit high activity and selectivity. When the quality ratio of Mo to y-Al2O3 is in the range from 1.25% to 2.5%, Mo to TiO2-Al2O3 prepared by the sol-gel method 1.25% and Mo to TiO2-Al2O3 prepared by the impregnation method from 0.675% to 1.25%, respectively, the activity and selectivity of the catalysts are 100%.Mo can improve the thermal stability of Ni-B/Y-Al2O3 and Ni-B/TiO2-Al2O3. The results of ICP, TPR and TPD indicate that the addition of Mo can increase the Ni loading, while the content of B can be decreased, and that it can make Ni reduced easier, produce new active center over the surface of the catalysts, weaken the strength of Ni-H bond and increase the numbers of adsorption center, which result in the activity increasing of the catalysts.The addition of Mo in Ni-B/TiO2-Al2O3 can increase the average pore width and pore volume, which can result in the diffusion of furfural alcohol from the surface of the catalyst easier. At the same time, the results of TPD exhibit that Mo can make... |
