Catalytic conversion of sucrose to 1,2-propanediol over alumina-supported Ni–Mo bimetallic catalysts

Abstract

Ni–Mo supported on γ-Al₂O₃ catalysts were synthesized to test its catalytic activity towards sucrose to 1,2-propanediol (1,2-PDO) conversion. The catalyst system was characterized using various physicochemical methods, including XRD, BET, py-FTIR, XPS, FE-SEM, HR-TEM and ICP. The metal combination of 8%Ni–20%Mo/γ-Al₂O₃ is found to be effective in producing a good yield of 1,2-propanediol (∼74%) under mild reaction conditions of 180 °C, 40 bar H₂ pressure and a run time of 4.5 h in a batch reaction. The activity of the active catalyst over various substrates such as cellulose, glucose, fructose and real-source biomass has also been investigated. XPS analysis of the active catalyst confirms the various oxidation states of the metals Ni and Mo in the active catalyst. The py-IR results show that the optimum Lewis to Brønsted acidic site ratio is responsible for the selective conversion of sucrose to 1,2-PDO. The presence of interparticle mesopores on γ-Al₂O₃ helps in the high conversion of sucrose. Furthermore, the catalyst has been found reusable for four consecutive runs without any structural or morphological changes.