The present contribution deals with model studies on ndecane isomerization over three bifunctional aluminophosphate-based catalysts. The isomorphous substitution of aluminum by magnesium in aluminophosphates with AEL, AFI, and AFO topology results in the formation of Brùnsted acid sites. The bifunctional catalysts 0.5Pt/MgAPO-11, 0.5Pt/ MgAPO-5, and 0.5Pt/MgAPO-41 are active in the isomerization of n-decane. Over the large pore catalyst Pt/MgAPO-5, hydrocracking is predominately observed, while isomerization dominates over Pt/MgAPO-41 and Pt/MgAPO-11. The observed high selectivity for n-decane isomers over these catalysts is primarily a consequence of the shape selective properties of these medium pore molecular sieves with AEL and AFO topology. The formation of the bulky dibranched and tribranched isomers, which are preferentially cracked, i.e., faster than the monobranched isomers, is restricted by the small pore width. The high selectivity for methyl nonanes observed over Pt/MgAPO-11 allows the assumption that these catalysts are also suitable for the isomerization of C 12 to C 18 alkanes with the aim of improving the low-temperature properties of diesel fuels or lube oils.
AcknowledgementsFinancial support of this work by Deutsche Forschungsgemeinschaft and Fonds der Chemischen Industrie is gratefully acknowledged.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.