Effect of alkali and alkaline earth metal ions on the catalytic epoxidation of styrene with molecular oxygen using cobalt(II)-exchanged zeolite X

Alkylation of phenol with t -butanol in the vapour phase on SAPO-11 catalyst has been studied. The main products are 4- t -butylphenol,2- t -butylphenol and 2,4-di- t -butylphenol, the last of these is the product of further alkylation of the 2- t -butylphenol.2- t -butylphenol easily isomerises to 4- t -butylphenol whereas the reverse reaction is not significant. Separate studies have shown that both butylphenols undergo easy dealkylation. The results of acid site poisoning by adsorption of bases as well as by sililation suggest that the reaction takes place essentially inside the zeolite pores.

Para-selective butylation of phenol over silicoaluminophosphate molecular sieve SAPO-11 catalyst

Dewaxing by an all-catalytic wax isomerization process has recently been commercialized for lube oil production. This new technology, which has a number of potential uses, is also the first major application of a silicoaluminophosphate molecular sieve. In this paper, the chemistry of the isomerization process over Pt-SAPO-11 is examined using both pure compounds and practical feeds, and compared to other catalysts. For Pt-S APO-11, the selectivity for pour point reduction with a minimum of branching is high, and the selectivity for secondary hydrocracking is low.

Studies on Wax Isomerization for Lubes and Fuels

Crystalline Microporous Phosphates: a Family of Versatile Catalysts and Adsorbents

Catalytic activities of alkali ion-exchanged zeolites, alumina, alkali treated alumina and hydrotalcite having varied Mg/Al molar ratio were evaluated for aldol condensation of propanal in liquid phase under solvent free conditions. The maximum conversion (97%) of propanal with 99% selectivity of 2-methylpentenal was obtained at 100 °C and 10 h using activated hydrotalcite of Mg/Al molar ratio of 3.5 as a catalyst. The basicity of the activated hydrotalcite of Mg/Al ratio 1.5, 2.5 and 3.5 was evaluated by isomerization of β-isophorone to α-isophorone as a model test reaction reported for basicity measurement. The effect of amount of catalyst and temperature on the conversion of propanal, selectivity of 2-methylpentenal and initial rate of reaction were studied in detail. The activation energy for propanal condensation under solvent free condition was found to be 58 kJ using activated hydrotalcite of Mg/Al molar ratio 3.5 as a catalyst. The catalyst was recycled six times without any significant loss in conversion and selectivity.

Liu Yang

Papers

Acidity, diffusion and catalytic properties of the silicoaluminophosphate SAPO-11