1,4-丁炔二醇温和条件下Pd-Ni基加氢催化剂的研究

Investigation on the Pd-Ni based catalysts for 1,4-butynediol hydrogenation under mild condition

鉴于1,4-丁炔二醇加氢制1,4-丁二醇的生产工艺一般涉及高压高温,分别以α-Al2O3和碳纳米管(CNTs)为载体,研究了近室温(30℃)近常压(0.2MPa)下1,4-丁炔二醇的Pd(Ni)基催化剂的加氢性能及其结构特征.结果发现,Pd-Ni双金属催化剂可以实现1,4-丁炔二醇的完全转化.对于产物1,4-丁二醇的选择性,还原法制备的1%Pd-1%Ni/CNTs仅达60.6%,而分步浸渍法制备的1%Pd-1%Ni/α-Al2O3和1%Pd-1%Ni/CNTs则分别达到89.1%和98.9%.X射线衍射(XRD)、氢气程序升温还原(H2-TPR)及透射电镜(TEM)等表征结果表明:具有合适相互作用、合金形式(部分)以及高度分散的Pd-Ni物种对1,4-丁炔二醇加氢具有重要作用,有利于反应中间产物1,4-丁烯二醇进一步加氢至1,4-丁二醇;且CNTs具有较优的储氢能力,以CNTs为载体有利于提高Pd-Ni基催化剂表面的氢浓度,进而促进1,4-丁烯二醇加氢.

The production of 1,4-butanediol(BDO)from 1,4-butynediol(B3D)is usually under high pressure and high temperature.In this study,the hydrogenation properties and structural characteristics of the Pd(Ni)based catalysts supported onα-Al2O3 and carbon nanotubes(CNTs)respectively for B3D hydrogenation were investigated under close to room temperature(30℃)and atmospheric pressure(0.2 MPa).The results demonstrate that B3D hydrogenation can be completely converted with Pd-Ni bimetallic catalysts.Selectivity of BDO just achieved 60.6%for 1%Pd-1%Ni/CNTs synthesized with chemical reduction method,while it increased to 89.1%and 98.9%for 1%Pd-1%Ni/α-Al2O3 and 1%Pd-1%Ni/CNTs catalysts prepared with stepwise impregnation method.The characterization results from X-ray diffraction(XRD),hydrogen temperature-programmed reduction(H2-TPR)and transmission electron microscope(TEM)show that the high-dispersed Pd-Ni species,partially composed of alloy and with suitable interactions,play a vital role in B3D hydrogenation,and improve the ability of hydrogenation of 1,4-butenediol(B2D)to BDO.Besides,the CNTs with excellent hydrogen-storage performance,when used as supports,lead to the increase of hydrogen species concentration on the surface of Pd-Ni based catalyst,and promote the hydrogenation of B2D to BDO.