Abstract:

Vinyl acetate has recently become one of the important basic organic material.Its present production is 4 million mt/year,it's growth is estimated at a millumum 4%annually to the year 2005.The key technology for the promotion of vinyl acetate for a fixed reaction equipment is the improving of catalyst^[1].In this paper, three types of catalysts were made whose active component distribution defferent from each other^[2].The distribution of Pd-Au on the catalyst is identified by EPMA.The vinyl acetate fixed bed reactor was used to evaluate the catalytic properties.A transmittance electronic microscope(TEM) was used to generate the appearance maps of Pd-Au distribution on silica carrier;H₂ chemisorption for TPR measurements were performanced using a pulse flow system. The paper investigates the effet of Pd-Au distribution on the catalyst dynamics parameter,reaction activity and selectivity,surface appearance and TPR, it is shown that the catalyst whose active components distributing on surface of carrier has better dispersion,higher by-reaction activation energy,low main-reaction activation energy contrasted to egg white and homogenous catalyst TPR results show that non-homogeneous catalyst has two TPR peaks,and homogeneous catalyst has one peak.