水溶剂中Pd-Ni/γ-Al_2O_3催化剂上糠酸加氢

制备了Pd-N i/γ-A l2O3催化剂,应用程序升温还原和程序升温脱附技术考察了催化剂的表面性质与催化加氢性能的关系。实验结果表明,Pd-N i/γ-A l2O3催化剂表面存在两种活性中心,催化加氢反应主要在较弱的活性中心上进行。采用连续流动固定床微型反应器考察了水溶剂体系中Pd-N i/γ-A l2O3催化剂上糠酸加氢生成四氢糠酸的反应,研究了反应条件对催化反应性能的影响,在2.5M Pa、200℃、氢气空速4 000h-1、糠酸水溶液的空速8.0h-1、氢气与糠酸的摩尔比50的条件下,糠酸转化率为96.8%,四氢糠酸选择性为100%,催化剂连续运转200h后催化活性没有下降。

Furoic Acid Hydrogenation over Pd-Ni/γ-Al_2O_3 Catalyst in Water

Supported Pd-Ni/γ-Al_2O_3 bimetallic catalyst was prepared and characterized by means of H_2 temperature-programmed reduction(H_2-TPR)and H_2 temperature-programmed desorption(H_2-TPD)to study relationship between catalyst performance and its surface properties.There were two kinds of active sites on the catalyst.Hydrogenation occured mainly on weaker active sites.Furoic acid hydrogenation over the catalyst in fixed bed micro-reactor was investigated under different conditions.When optimal conditions were:reaction pressure(2.5MPa,)reaction temperature 200℃,H_2 space velocity 4 000h~(-1),liquid space velocity of furoic acid(8.0h~(-1)) and(n(H_2) ∶n(furoic acid)=50,)conversion of furoic acid was up to 96.8%,and selectivity of tetra-hydro-furoic acid dramatically reached 100%.No deactivation of catalyst was observed after hydrogenation for 200h.