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通过改变溶液中的Na_2WO_4浓度以化学还原法制备了一系列超细非晶态NiWB合金,并用于葡萄糖高压液相加氢制取山梨醇.研究表明NiWB合金的催化活性均远高于Raney Ni.同时XPS揭示了钨的加入可以调变元素态硼的给电子能力,进而影响硼对羰基的活化和镍对氢的解离吸附能力.在活性最佳的NiWB-3合金上的基本动力学研究表明,葡萄糖加氢反应对氢压为一级,对葡萄糖浓度为零级,在373～403 K范围内的反应活化能为54.7kJ·mol~(-1).
A series of ultrafine amorphous NiWB alloys were prepared by chemical reduction method by changing the concentration of Na_2WO_4 in solution, and were used for high-pressure liquid-phase hydrogenation of glucose to produce sorbitol.The results show that the catalytic activity of NiWB alloy is much higher than that of Raney Ni. At the same time, XPS revealed that the incorporation of tungsten can change the electron-donating ability of elemental boron, which in turn affects the activation of carbonyl and the dissociative adsorption of hydrogen on nickel. The basic kinetics of NiWB-3 alloy The results showed that the hydrogenation pressure of glucose was first order, the concentration of glucose was zero order, and the activation energy was 54.7kJ · mol ~ (-1) in the range of 373 ~ 403 K.