Pd catalysts supported on Nb2O5-γ-Al2O3 composite oxides with high activity and stability in 2-methylfuran hydrogenation to 3-acetyl-1-propanol

Abstract

3-Acetyl-1-propanol, which could be produced by 2-methylfuran hydrogenolysis, is a valuable chemical with wide applications in both pharmaceutical and chemical industries. The development of bifunctional solid acid catalysts to replace the conventional hydrochloric acid process is important to decrease production costs. Nb₂O₅ is a widely known solid acid, but its low specific surface area and small pore volume hinder its industrial applications. In this work, niobic acid is introduced into γ-alumina via coprecipitation to prepare Nb–Al composite oxides. Pd catalysts supported on Nb–Al composite oxides showed ideal textural properties with advantages of both Nb₂O₅ and γ-Al₂O₃. In 2-methylfuran hydrogenolysis, the 3-AP yield increased from 60.6% to 82.7%, and the cycling stability improved significantly compared to that of a catalyst supported on γ-Al₂O₃. It is proposed that the catalytic activity and selectivity are primarily influenced by the metal–acid balance, and a quantitative relationship between the ratio of metal–acid sites and catalytic performance was established. The analysis of reaction mechanisms revealed that a balanced number of Lewis acid sites and metallic sites were crucial for achieving a high yield of 3-acetyl-1-propanol.