摘要
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 in aqueous solution with various concentration of Na2WO4. It is found that their catalytic activities are strikingly higher than that of Raney Ni catalyst in liquid phase glucose hydrogenation to sorbitol. XPS analysis revealed that tungsten can tailor the electron donation ability of elemental boron, which affects carbonyl group activation for glucose by boron as well as the dissociative adsorption of hydrogen on nickel. Fundamental kinetic study on the optimal NiWB - 3 alloy showed that hydrogenation is first order to hydrogen and zero order to glucose. The activation energy in the temperature range of 373 - 403K is estimated to be 54.7kJ@mol-1 .
出处
《化学学报》
SCIE
CAS
CSCD
北大核心
2000年第7期904-908,共5页
Acta Chimica Sinica
关键词
镍钨硼合金
葡萄糖
山梨醇
液相加氢
催化活性
NiWB alloys, amorphous, glucose, sorbitol, liquid phase hydrogenation
