Catalytic self-etherification of 5-hydroxymethylfurfural to 5,5′(oxy-bis(methylene))bis-2-furfural over zeolite catalysts: effect of pore structure and acidity

The self-etherification of 5-hydroxymethylfurfural (HMF) to 5,5′(oxy-bis(methylene))bis-2-furfural (OBMF) was investigated on ZSM-5, MCM-22, Beta and hierarchically micro-mesopores ZSM-5 (HMZ) catalysts. The hierarchically structured zeolites exhibited a superior intrinsic activity and good resistance to carbonaceous deposit, the latter which could be ascribed to the lower mass transfer barrier in mesopores of HMZ catalysts. The structure-activity correlation showed that catalytic activity majorly originated from one or several specific Bronsted acid sites, providing key clues to design the efficient zeolite catalysts for producing OBMF.