【摘要】 <正> 研究固体表面上催化反应的核磁共振(NMR)方法是近十几年来发展起来的较新的波谱学方法.该法特点是可直接观察在固体表面上反应物与产物浓度的变化,了解吸附分子与表面相互作用力的性质,探测在表面上生成的中间产物,推断反应机理,特别是还可获得吸附分子在固体表面上活动性的动态信息.NMR方法主要用于研究液体样品,对固体样品通常只能获得宽线谱图.但对吸附体系来说,由于物理吸附在本质上类似更多还原

【Abstract】 The hydrogenation of ethylene on Pt/NaY catalysts was studied by 1H NMR method. In the reaction system, some of adsorbent NaY was placed in the probe of NMR spectrometer to monitor the concentration change of the reactants and products in the system. The adsorbent NaY was arranged in two different manners: in directly contact with the catalyst or without contact with it, as shown in Fig. 1( a ) and Fig. 2 (a) respectively. It was found that in the former case the rate of hydrogenation reaction was much faster than in the latter case as indicated in Fig. 3.The results were discussed in terms of the spillover of ethane formed in the hydrogcnation reaction, i. e. in direct contact case, C2H6 formed migrates firstly along the surface of solid from Pt particles of catalyst to the surface of support NaY and then to the adsorbent NaY surface. And in the case of non-contact,C2H6 has to be desorbed from the surface of catalyst into the gas phase, this is an energy-needed activation process, therefore, the hydrogenation rate of which is slower than that of the spillover process.更多还原