Transition metal promoted AlPO4 catalyst 2. The catalytic activity of M0.05Al0.95PO4 for alcohol conversion and cumene cracking/dehydrogenation reactions

Abstract

The 2-propanol and methanol conversion over M0.05Al0.95PO4 (M = VO, Cr, Mn, Fe, Co, or Ni) catalysts was studied at different temperatures and flow rates in a fixed bed catalytic reactor while cumene cracking/dehydrogenation reaction was carried out in a micropulse reactor. The low acetone selectivity from 2-propanol in nitrogen and air indicated the presence of an insufficient number of weak redox sites in all samples. Among all the samples, VOAlPO4 showed the highest conversion and also selectivity for olefins. Selectivity studies indicated that 2-propanol and methanol dehydration followed a combination of parallel and consecutive pathways. On all the samples, selectivity of cumene cracking product is very low. However, all the samples showed appreciable dehydrogenation activity. Participation of Bronsted acid sites in the dehydration as well as cracking reactions is supported by the surface poisoning studies. A good correlation was observed between the acidity and the dehydration activity of all the samples. (C) 1998 Elsevier Science B.V.