Highly Controllable Hydrogenative Ring Rearrangement and Complete Hydrogenation Of Biobased Furfurals over Pd/La₂B₂O₇ (B=Ti, Zr, Ce)

Developing a highly selective catalyst to upgrade furfurals (5-hydroxymethyl furfural and furfural) to cyclopentanones (3-hydroxymethyl cyclopentanone and cyclopentanone) and tetrahydrofuran alcohols (2,5-bishydroxymethyl tetrahydrofuran and tetrahydrofuran alcohol) is highly significant for biobased fine chemical synthesis. Here, a series of La₂B₂O₇ (B=Ti, Zr, Ce) metal oxides, featuring the same chemical formula but different topological structures are fabricated. After Pd loading, the Lewis acidity and metal-support interaction are well governed by the support type, which further affects the hydrogenation and acid-catalyzed ability. A greater than 82 % yield of cyclopentanones is obtained via a hydrogenative ring rearrangement route over Pd/La₂Ti₂O₇. However, Pd/La₂Ce₂O₇ shows high catalytic efficiency for tetrahydrofuran alcohols with an approximately 80 % yield via a complete hydrogenation route. Additionally, the catalyst exhibits outstanding recycling performance and structural stability. This study presents an interesting design strategy for the selective preparation of cyclopentanones and tetrahydrofuran alcohols through the regulation of the adsorption mechanism.