Efficient hydrogenolysis of furfuryl alcohol to 1,5-pentanediol over NiLa@ZrO₂ catalyst

One-pot conversion paths of C5 substrates to 1,5-pentanediol (1,5-PDO) will allow efficient production of polyesters, polyurethanes and fungicides. Although efficient conversion of tetrahydrofurfuryl alcohol (THFA) to 1,5-PDO has been achieved, selective production of 1,5-PDO from hemicellulose-derived furfural (FF) or from furfuryl alcohol (FFA) in high yields has yet to be reported. Herein, direct conversion of FFA to 1,5-PDO was achieved in yields as high as 72.5 % over NiLa@ZrO₂ catalyst. The combination of La species with ZrO₂ effectively increased the abundance of basic sites and oxygen vacancies on the catalyst and the close proximity of Ni⁰ and basic sites facilitated both homolytic and heterolytic dissociation of H₂ molecules. In the mechanistic pathway, the C=C bond of FFA was first hydrogenated by homolytic H atoms of H₂ molecules to form tetrahydrofurfuryl alcohol and then heterolytic H^δ− and H^δ+ species acted to cleave the C₂-O bond in tetrahydrofurfuryl alcohol activated by basic sites and oxygen vacancies of the catalyst to afford 1,5-PDO. The results of this work demonstrate the possibility of directly and efficiently upgrading FFA to 1,5-PDO using non-precious metal catalysts.