화학공학소재연구정보센터
Chemical Engineering & Technology, Vol.17, No.2, 112-118, 1994
DEACTIVATION OF A VINYL-ACETATE CATALYST
Kinetic studies as well as morphological and physico-chemical surface studies have been carried out on the deactivation of a palladium carrier catalyst for vinyl acetate synthesis in the ethylene gas phase process. The experiments cover concentration and temperature ranges of technical interest at a total pressure of 900 kPa. The deactivation rate depends on the temperature and the oxygen and acetic acid concentrations. The decline in activity is best described by a rate law of second order relative to the activity number. This behaviour is attributed to the observed aggregation of finely dispersed palladium. It can be concluded that palladium(II) acetate acts as a transport species in a chemically assisted sintering mechanism. At temperatures T less-than-or-equal-to 438 K the more advantageous final texture of the catalyst will only be formed on reaction.