A Comparative Catalyst Evaluation for the Selective Oxidative Esterification of Furfural

Catalysts based on gold or other metals on different supports were studied in the selective oxidative esterification of furfural with methanol to methyl 2-furoate. Methyl 2-furoate can be used in specialty fragrances, a high added-value application. Catalyst evaluation and selection were performed using the Avantium quick catalyst screening (QCS) platform using industrially relevant conditions. The best performances were exclusively obtained with gold based catalyst supported on ceria or titania, though these catalysts showed rather poor behavior in tests with a different furfural to methanol ratio. Selected gold catalysts were studied subsequently in a conventional lab-scale autoclave under reaction conditions closer to those commonly applied in literature and effects of support type and preparation were included. For each of the two testing conditions a different catalyst was identified as the most optimal, which is explained by the strong chemisorption of furfural on the Au surface. Au/ZrO2 catalysts, identified as optimal in QCS tests, show also high performances (about 99 % yield) in autoclave tests, although a different preparation was employed.