The Role of Deposited Poisons and Crystallite Surface Structure in the Activity and Selectivity of Reforming Catalysts

Over the past three decades catalytic reforming has evolved very rapidly to the point where it is now one of the most important industrial applications of catalysis [1]. The process was originally developed to produce gasoline components of high antiknock quality, in response to the fuel requirements of high compression ratio automobile engines. The objective of the process is to convert saturated hydrocarbons (alkanes and cyclo-alkanes) in petroleum naphtha fractions to aromatic hydrocarbons as selectively as possible, since the latter have excellent antiknock ratings. Naphtha fractions are composed of hydrocarbons having boiling points within the approximate range of 320–470 K. Reaction temperatures of 700–800 K and pressures of 10–35 atm are employed in the process. The catalysts employed commonly contain platinum or a combination of platinum and a second metallic element such as rhenium or iridium [2].