Kinetics and mechanistic insights into hydrogenative rearrangement of hydroxymethylfurfural over acid-Nickel catalysts

Catalytic hydrogenative rearrangement of furanic aldehydes is crucial for producing biomass-derived cyclopentanone fine chemicals. However, designing highly selective catalysts remains challenging due to the interplay among tandem hydrogenation, ring-opening, aldol condensation, dehydration, and parallel ring-hydrogenation. Here, we employ a single self-assembly step by depositing phosphonic acids (PAs) on conventional Ni catalysts to introduce tunable interfacial Brønsted acid sites (BAS), resulting in an unprecedented 3-hydroxymethyl-cyclopentanone yield of 95.8% from hydroxymethylfurfural. Kinetic studies reveal a one-order-of-magnitude increase in ring-opening rates—the slow step in hydrogenative rearrangement—after PAs modification, accompanied by a drop in the apparent activation energy from 154.1 to 105.4 kJ mol⁻¹. In contrast, the activation energy for the ring-hydrogenation side reaction remains almost unchanged. Theoretical calculations suggest that BAS synergize with adjacent Ni to lower the C–O cleavage barrier by providing protons to attack the hydroxymethyl oxygen atom, which is the key step to initiate ring-opening.