ENHANCED CATALYTIC ACTIVITY OF SILICA-ALUMINA MODIFIED BY PHOSPHORIC ACID FOR THE ISOMERIZATION OF n-BUTENE

Abstract

Silica-alumina was modified by phosphoric acid, and the resulting materials (SiAP) were investigated in terms of catalytic activity and selectivity for n-butene isomerization as well as physicochemical properties. The activity of SiAP catalysts outgassed at 400°C increased sharply with increasing amount of phosphoric acid added, and reached a maximum at 4.8% H₃PO₄: the maximum activity value was about twice of that of the original silica-alumina. This enhancement in activity was accounted for by an increase in Bröonsted acid sites.