Catalyst, Shape-selective

Name:
Catalyst, Shape-selective
Detailed information:
A catalytic solid (transition metal) introduced into a crystalline aluminosilicate (zeolite) having pores or openings of approximately 5 Å. This permits the catalyst to exert a selective effect between molecules that differ in shape rather than in the reactivity of their chemical groups. The cage structure of the zeolite effectively prevents contact of the catalyst with all molecules whose shapes and sizes exclude their entry. The ability of a catalyst to discriminate among molecules on the basis of their shapes is of great value in the cracking of straight-chain hydrocarbons and has attractive possibilities in other types of catalytic reactions.See Zeolite; Cage Zeolite.