Oxygen vacancy-rich metal oxides and Co-Cu alloy bifunctional sites for selective conversion of furfural to 1,2-pentanediol and 1,5-pentanediol

Abstract

One-step conversion of biomass-derived furfural (FA) to 1,2-pentanediol (1,2-PeD) and 1,5-pentanediol (1,5-PeD) by selective cleavage of COC is of great significance. However, the lack of knowledge of the active sites in this reaction leads to poor catalytic performance over the currently used non-noble metal hydrogenation catalysts. In this work, xCoyCu/MgAlO_x-T catalysts with Co-Cu alloy as well as O_v-rich CuO and CoO bifunctional active sites were constructed by modulating the metal ratio and reduction temperature. During the reaction, the Co-Cu alloy enhanced the H₂ dissociation efficiency and hydrogenation of FA to furfuryl alcohol (FOL). In addition, the COC is inclined to adsorb on the O_v-rich CuO and CoO, while the active H* dissociates from the Co-Cu alloy and spills out onto the surfaces of CuO and CoO to participate in the hydrogenation reaction. Moreover, DFT calculation shows that O_v-rich CuO and CoO significantly reduce the cleavage energy barrier of COC bond, leading to 22.57 % yield of 1,2-PeD and 49.78 % yield of 1,5-PeD over 3Co1Cu/MgAlO_x-600. This study provides an in-depth understanding of the reaction mechanism of FA conversion to 1,2-PeD and 1,5-PeD, as well as offers a viable approach for the construction of bifunctional catalysts.