膜催化研究 Ⅱ.多孔无机膜的制备与表征及其反应器对甲醇脱氢反应的促进作用

Studies of Membranes Catalysis Ⅱ. Preparation and Characterization of Porous Inorganic Membranes and Their Promoting Effect on Dehydrogenation of Methanol

采用溶胶-凝胶法制备了多孔氧化铝膜,并通过DSC、TGA、SEM、N_2吸附和气体透过率测定等手段,对膜的性能进行了表征.结果表明,用这种方法制备的多孔氧化铝膜是一种均匀无裂痕和具有较窄孔径分布(约4nm)的膜材料.将此多孔氧化铝膜制成膜反应器后,用于甲醇催化脱氢制甲醛的反应,发现甲醇转化率比常规反应器有较大幅度的提高.同时首次尝试采用溶胶-凝胶法将催化活性组分直接负载到多孔氧化铝膜上,从而得到了一种具有催化活性的多孔膜,并考察了它的反应活性.文中对由这两种多孔膜及钯/陶瓷复合膜制成的反应器的特点进行了比较.

Porous alumina membranes were prepared by the sol-gel process and were characterized by DSO, TGA, SEM, nitrogen adsorption and gas permeation test. The results showed that the membranes thus prepared were uniform and crack-free, with a narrow distribution of pore sizes. The catalytic dehydrogenation of methanol were carried out in a reactor incorporated the alumina membrane and the conversion of methanol was found to be remarkably increased compared to that in a conventional reactor. Atso, for the first time, the catalytic compositions were deposited onto the porous alumina membranes by the sol-gel process and thus catalytic porous membranes were obtained and their catalytic activities were investigated.The characteristics of the two kinds of porous membranes (catalytic and non-catalytic) and the palladium/ ceramic membrane were compared as they were in a membrane reactor.