Aqueous phase reforming of glycerol to 1,2-propanediol over Pt-nanoparticles supported on hydrotalcite in the absence of hydrogen

Abstract

Pt-nanoparticles, in the range of 2–5 nm, supported on hydrotalcite (HT), were used as a catalyst for the selective hydrogenolysis of glycerol to produce 1,2-propanediol by aqueous phase reforming in the absence of any added hydrogen. The catalyst was characterized by XRD, N₂-sorption, pulse chemisorption, TPR, XPS, SEM, TEM, EXAFS. The influence of reaction parameters like reaction time, pressure, etc., were studied in detail. The study reveals that the Pt-nanoparticles are the active sites for the selective conversion of glycerol to 1,2-propanediol. The role of the support also plays an important role in the hydrogenolysis. The hydrogen required for the hydrogenolysis is derived from the reforming of H₂O over the Pt-HT catalyst. The mechanism of the hydrogenolysis reaction is also proposed. A glycerol conversion of 98% with a 1,2-propanediol selectivity of 74% was achieved over 3 wt% Pt supported on HT. The reusability of the catalyst was tested by conducting four runs with the same catalyst and it was found that after four reuses, the conversion and selectivity was almost same.