Preparation of Electrically Heated Aluminium Wire Catalyst

主要研究结果如下：（1）在草酸电解液中，用阳极氧化法在铝丝表面制备了多孔氧化铝膜。孔径大小可以通过阳极电位来控制，氧化铝膜的厚度是阳极氧化时间以及所用阳极电位的函数。(2)二氧化硅粉末含有细分镍金属颗粒被纳入氧化铝膜的微孔通过浸渍法使用溶胶-凝胶溶液组成的硅酸乙酯和硝酸镍溶解在乙二醇中。(3)这种金属丝催化剂在催化反应期间不需要任何辅助加热，因为在金属丝两端施加小电压30秒后，可以达到573 K的温度。(4)测定了负载在铝丝上的镍颗粒对1-丁烯加氢反应的催化性能，并与传统的镍催化剂进行了比较，结果表明两种催化剂的活化能相同，铝丝催化剂的特点之一是在两端施加小电压时升温速率快，提出了在汽车冷启动排放催化剂中的应用。研究了要掺入铝丝微孔中的催化剂组分;主要研究了铑和铈的氧化物。

Main results obtained in thw present research are as follows ;(1) Porous alimina films have been prepared on the surface of an aluminium wire by an anodic oxidation in an oxalic acid electrolyte. The pore size could be controlled by the anode potential, and the thickness of the alumina film was a function of the anodizing time as well as the anode potential used.(2) Silica powders containing finely-divided Ni metal particles were incorporated into the micropores of the alumina films by an impregnation method using sol-gel solution consisting of ethylsilicate and nickel nitrate dissolved in ethylene glycol.(3) This wire catalyst did not require any supplimentary heating during catalytic reactions, since after 30 sec of applying a small voltage across the ends of the wire, a temperature of 573 K could be reached.(4) The catalytic performance of the Ni particles mounted in the aluminium wires for hydrogenation of 1-butene was measured and compared with that of a conventional supported-nickel catalyst, resulting in the same activation energies in both catalysts.One of the featires of the aluminium wire catalyst is in the high temperature-rising rate by applying a small voltage across the ends of the wire, suggesting an application to a catalyst for cold-start emission of automobile. The catalyst conponents to be incorporated into micropores of the aluminium wire were investigated ; rhodium and cerium oxides were preominantly investigated.