COMPARATIVE-STUDY OF THE W USY AND NI/USY ZEOLITIC CATALYSTS DEACTIVATION/

The deactivation of W/USY and Ni/USY zeolitic catalysts, prepared at d ifferent pHs, was studied, and several relationships were used to desc ribe the process and calculate the initial activities. The calculated amount of coke deposited on the catalysts follows Voorhies equation, a nd the deactivation is well described by a combined first and second o rder expression. No mechanistic conclusion concerning the deactivation process could be drawn but similarities with reported results show th at it can be correlated to the coke deposition and to the samples acid ity.