ABSTRACT
In the study of the selective hydrogenation of unsaturated aldehydes (UAL), it is desirable to find catalysts that will preferentially reduce the C=O functional group while keeping the C=C bond intact. Despite reports of industrial catalysts that can achieve high selectivity towards unsaturated alcohols (UOL), the factors governing selectivity are still not clearly understood. This chapter addresses both promoter and support effects on product selectivity in the gas-phase hydrogenation of 3-methyl-2-butenal over potassium promoted Ru/SiO2 and ruthenium supported on NaY and K-exchanged NaY zeolites. Potassium-exchanged NaY (KY) was prepared from NaY zeolite by ion exchange. Ru-loaded catalysts were then prepared by ion exchange of the two zeolite supports to a nominal weight loading of 3% as described in detail in. The zeolite-supported catalysts gave UOL selectivities intermediate to the two silica-supported catalysts. Exchanging the charge compensating ion in the zeolite from Na to K caused an increase in UOL selectivity from about 40% to about 60%.
