Catalytic transfer hydrogenation of furfural to furfuryl alcohol over Al-containing ferrihydrite

Abstract

Al-containing ferrihydrite (Fh-Al) was prepared by co-precipitation method using ferric nitrate nonahydrate and aluminum nitrate nonahydrate as precursors. The prepared Fh-Al was systematicallycharacterized and then employed for the catalytic transfer hydrogenation (CTH) of furfural (FUR) to furfuryl alcohol (FOL). The influence of precipitant type, hydrogen donor, the molar ratio of Fe to Al, catalyst amount, reaction time and reaction temperature were investigated. It was found that Fh-Al with 1:2 molar ratio of Fe to Al was amorphous with acidic and basic sites, and the largest specific surface area of 303 m2/g was obtained using NaOH and Na2CO3 as the co-precipitator. Fh-Al with 1:2 molar ratio of Fe to Al possessed excellent catalytic performance and stability. The conversion of FUR, the yield and the selectivity of FOL reached 100 % at 150 °C for 5 h using isopropanol as the hydrogen donor. Moreover, only slight decrease in the catalytic performance was observed during the recycle. After 4 cycles, the conversion of FUR, the selectivity and the yield of FOL still reached 99.1 %, 99.7 % and 98.8 %, respectively. A plausible reaction mechanism for the CTH of FUR to FOL was also proposed, in which both acidic and basic sites play roles.