Poison-resistant Zeolite Catalysts

Abstract

A BRIEF investigation has been made of the possibility of producing poison-resistant catalysts for some gas–solid reactions by using the molecular sieve properties of zeolites. Most catalyst poisons act either by being adsorbed more strongly on to the catalyst than the reactants or by reacting on the catalyst to give products which are strongly adsorbed. The reactive catalytic species are in many cases metal ions or atoms on the surface of the catalyst where they are freely accessible to poison molecules. By enclosing the catalytic ions or atoms within the pores of a zeolite having the correct pore size it should be possible to prevent access of large poison molecules to the catalytic ions while smaller reactant molecules have easy access.