CATALYTIC PROPERTIES OF PENTASILS IN THE VAPOR-PHASE ALKYLATION OF PHENOL WITH METHANOL

The catalytic properties of the H-forms of pentasils have been investi gated that differ in their SiO2/Al2O3 ratio, the distribution of the a cid sites on the sil, and of high-silicon zeolites, modified with P2O5 and MgO, in the vapor-phase alkylation of phenol with methanol. The r eaction products are anisole, o-cresol, and 2,6-xylenol, p- and m-cres ols, and isomeric xylenols, with 2,4-and 2,5-xylenols predominating in the xylenol fraction. The influence of the process conditions and of the acidity of the samples on the o-cresol/p-cresol and the m-cresol/p -cresol ratios has been established. It has been demonstrated that mod ification of the pentasils with P2O5 and MgO increases the selectivity of p-cresol formation by a factor of 1.5-2.