Preparation of bimetal Co–Ni supported on Mg–Al oxide for chemocatalytic upgrading of tailored fermentation products to energy intensive fuels

Abstract

The great challenge in the aldol condensation of tailored fermentation products (acetone–butanol–ethanol, ABE) into energy intensive fuels is to develop a suitable catalyst with high activity and low–cost. In this study, Co, Ni, and Co–Ni supported on Mg–Al oxide catalysts were prepared and their pore diameters were enlarged via adding active carbon as a hard template into Mg–Al hydrotalcite. During the aldol condensation reaction, the catalyst activity was enhanced after enlarging the pore diameter and Co–Ni bimetal supported catalyst presented the highest activity, which was resulted from that the electron transfer between Co and Ni in Co–Ni alloy enhanced the dehydrogenation activity and large pore lowered the mass transfer resistance. After optimizing the reaction conditions, acetone conversion and the total selectivity of C5–C11 desired products in the aldol condensation of ABE reached up to 76% and 90%, respectively. The stability study showed that the activity was decreased with the increase of reaction number because of the oxidation of metallic Co and Ni, but this could be solved via a simple hydrogen reduction method.

Keywords

• Fermentation products
• Aldol condensation
• Active carbon
• Energy intensive fuel
• Co–Ni alloy