Selective Transfer Hydrogenation of Furfural into Furfuryl Alcohol on Zr-Containing Catalysts Using Lower Alcohols as Hydrogen Donors

Abstract

A series of zirconium-based catalysts were prepared for the selective transfer hydrogenation of biomass-derived furfural (FFR) into furfuryl alcohol with lower alcohols as hydrogen sources. The sample structures were clearly characterized using various methods, such as X-ray powder diffraction, thermogravimetric analysis, scanning electron microscope, NH₃-temperature-programmed desorption (TPD), CO₂-TPD, and nitrogen physisorption. Excellent furfuryl alcohol yield of 98.9 mol % was achieved over Zr(OH)₄ using 2-propanol as a hydrogen donor at 447 K. The poisoning experiments indicated that basic centers displayed pronounced effect for FFR transfer hydrogenation. Moderate monoclinic phase content in ZrO₂-x enhanced the conversion rate and furfuryl alcohol selectivity, whereas acid-basic site density ratio had slight influence on FFR conversion. Besides, Zr(OH)₄ revealed good performance and stability after being repeated four times. The possible mechanism for this transfer hydrogenation process over Zr(OH)₄ catalyst with 2-propanol as the hydrogen source was proposed.