Abstract

Before the US. Patent (1949) by Haensel wherein platinum was used as the active metal component in the industrial catalytic reforming catalysts, molybdenum and /or chromium oxides were used but were suffering from very rapid deactivation by coke even when used under high pressures. Platinum containing catalysts enjoyed very high selectivity via producing high yields of high octane C5 + reformates even at relatively much lower pressures. Improvements were then carried out; some concerned with modifying the metal component, and others concerning modifying the support as well as improving the processing schemes. So many patents were disclosing bimetallic or even polymetallic catalysts containing primarily platinum and/or rhenium or iridium, or their combinations, in addition to tin, zinc, germanium, bismuth, phosphorus, or chlorine, etc. These catalysts acquired advantageous activities, selectivities and long time-on stream with maintaining high yields of high octane motor gasoline.

Keywords: Platinum, rhenium, iridium, Al2O3, aromatization, isomerization