Alloying Cobalt in Co-Fe-Al Catalyst for Achieving the Selective Conversion of Furfural to Cyclopentanone

Abstract

Production of the fine chemicals like cyclopentanone (CPO) and cyclopentanol (CPL) from biomass-derived furfural is attractive but challenging, as deep hydrogenation of furan ring in furfural hinders formation of the targeting products. In this study, an alloying strategy is proposed for selective conversion of furfural to CPO in aqueous phase over Co-Fe-Al catalysts. Comparing with Co-Al catalyst, the formation of CoFe alloy in Co-Fe-Al catalyst reduced interaction between the metal species and the alumina carrier, lowered adsorption/activation of H2, decreased the catalytic capability for hydrogenation, increased the activation energy for hydrogenation of furfural (from 17.2 kJ·mol-1 over Co-Al to 33.4 kJ·mol-1) and weakened the adsorption of C=C and C-O-C functionalities in furan ring of furfuryl alcohol (FA) on metallic sites. These factors together suppressed deep hydrogenation of furan ring in FA or the ring-opening of FA to diols, producing CPO and CPL with the sum yield of 91.5%. In addition, the presence of Fe in Co-Fe-Al catalysts also enhanced the structural stability of Co species, preventing the phase transformation and agglomeration of metallic Co species and rendering the catalyst with the superior reusability.

Keywords: furfural, cyclopentanone, Co-Fe-Al catalyst, CoFe alloy, hydrogenation