Ru-Ni/WO_(3)催化剂的制备及其催化纤维素制乙二醇

Preparation of Ru-Ni/WO_(3) Multifunctional Catalyst and Its Catalytic Performance for Cellulose to Ethylene Glycol

以商业氧化钨(WO_(3))为载体,通过调控制备工艺和活化方式制备了一系列钨基金属催化剂并探索其催化性能。研究结果表明:通过浸渍负载法制备并采用NaBH_(4)液相活化制备的Ru-Ni/WO_(3)催化剂,Ru和Ni的负载量分别为2%和20%,其表现出较好的纤维素氢解制乙二醇的催化性能,在240℃、4 MPa氢压下,反应4 h可以得到86.1%纤维素转化率和62.8%的乙二醇选择性。采用XRD、SEM、Raman和XPS等表征手段探讨了催化剂组成和结构对其催化性能和产物分布的影响机制,Ni和Ru分步浸渍、然后NaBH_(4)液相还原活化的双金属催化剂会比普通浸渍和氢气热还原活化的催化剂更易被还原,同时具有更大的比表面积和金属分散性,表现出更多的表面缺陷和酸活性位,从而有利于催化纤维素直接氢解转化制备乙二醇。

Using commercial tungsten oxide as carrier,a series of tungsten fund metal catalysts were prepared and their catalytic properties were investigated by controlling the preparation process and activation method.Results showed that the Ru-Ni/WO_(3) catalyst(Ru loading 2%,Ni loading 20%),which was first impregnated with Ni and then loaded with Ru using sodium borohydride liquid-phase activation,exhibited better catalytic properties for cellulosic hydrogenolysis to ethylene glycol(EG).86% cellulosic conversion and 63% ethylene glycol selectivity were obtained at 240 ℃ and 4 MPa H_(2) pressure for 4 h.Subsequently,the characterizations of XRD,SEM,Raman,and XPS also employed to investigate the mechanism of the influence of catalyst composition and structure on its catalytic performance and product distribution.The results showed that bimetallic catalyst with Ni and Ru dipped step by step,and then actived by sodium borohydride liquid-phase reduction was easier to be reduced than the catalyst with normal dipping and hydrogen thermal reduction activation,and showed higher surface area and better dispersion of metal,with more surface defects and acid sites,thus was conducive to the occurrence of cascade reaction for cellulose to ethylene glycol.