Abstract
The selectivity change in a consecutive reactions system brought about by the deactivation of a catalyst is studied from the viewpoint of the intraparticle diffusion effect. First, by analysis based upon three types of simplified deactivation model, it is shown that the deactivation mechanism inside a catalyst particle exerts a strong influence upon the tendency of the selectivity change with deactivation through the time history of the distribution pattern of rate constants. Next, the deactivation of a nickel catalyst for the hydrogenation of acetylene is experimentally observed. The observed relations of the selectivity to the degree of deactivation well accord with one of the three models. In a detailed analysis, the micro-macro pore model proposed in previous papers1, 2), by the authors is used as the basis of this catalytic system. The mode! is proved to be reasonable for the deactivation process also.
