Among Ni supported on H-ZSM-5 catalysts with various loadings of Ni, a catalyst with 30 weight% Ni has been identified as an effective catalyst for the hydrogenation of levulinic acid to g-valerolactone in vapour phase at atmospheric pressure. The catalysts have been characterized by different techniques such as XRD, BET surface area, pore size distribution, TPR, AAS, pulse chemisorption, FE-SEM-EDS, TEM, XPS and pyridine-adsorbed IR. XRD patterns suggest that the structure of H-ZSM-5 is intact even after incorporation of Ni. Pyridine-adsorbed IR patterns reveal the presence of both Lewis and Brønsted acid sites, which are responsible for the dehydration and cleavage of g-valerolactone. The superior activity exhibited by the 30 wt% Ni/H-ZSM-5 catalyst (demonstrating the highest productivity of 0.9090 kg GVL kg catalyst À1 h À1 at 250 C) is due to the presence of a greater number of surface Ni species. Non-noble metal Ni-based catalysts offer advantages over the present processes involving Ru-based catalysts, which have certain constraints, some of which are unavoidable such as cost ineffectiveness, the use of volatile organic solvents and high pressure operation. The 30 wt% Ni/H-ZSM-5 catalyst can be seen as an alternative and promising catalyst which could be of great importance to the chemical industry.

A Ni/SiO2 catalyst is found to be effective for the hydrogenation of levulinic acid to yield γ-valerolactone with a quantitative yield in vapour phase conditions at atmospheric pressure without any additives.

No abstract

No abstract

An efficient route for the transformation of levulinic acid without an external hydrogen source in a continuous process over supported Ni catalysts.