Platinum-Carbon Catalysts with Molecular Sieve Properties SHAPE SELECTIVITY IN HYDROGENATION CATALYSIS

Applications of molecular sieve materials have become of increasing interest in catalysis. The ability of these materials to diferentiate on the basis of molecular size gives them a unique form of selective catalytic action uith the additional berrejit of high resistance to sorption of large poison molecules. Hitherto their major application has been realised with zeolites but new platinum catalysts possessing similar properties and based on a carbonaceous structure have now been developed in the Johnson Matthey Research Laboratories. Over the past few decades increasing inter-est has been aroused in the field of adsorp-tion, and to a lesser extent catalysis, by materials which, as a result of their structure, are capable of selectively differentiating between molecules of differing size. These materials, often described as molecula