Role of Support and Promoter in the Selective Conversion of Isophorone to 3,5-Xylenol over Chromia Catalysts

A detailed study has been undertaken regarding the role of support and promoter towards 3,5-xylenol selectivity improvements in the vapor-phase aromatization of isophorone. The supports used in this study include A12O3, SiO2, ZrO2, MgO and carbon-covered alumina for Cr2O3 catalysts. K2O has been used as a promoter for these catalysts. Influence of solvent during Cr2O3/MgO catalyst preparation step has also been studied. The parameters governing the aromatization selectivity observed from this study are: moderate acidic sites, coordinatively unsaturated sites of Cr2O3 and smaller crystallites of Cr2O3.