Chemoselective Lactonization of Renewable Succinic Acid with Heterogeneous Nanoparticle Catalysts

Keiko Yakabi,Alberto Roldan,Ceri Hammond,Alexandra Jones,Antoine Buchard

doi:10.1021/acssuschemeng.8b03346

Abstract

The production of chemicals from renewable resources, resulting in the establishment of biorefineries, represents a challenge of increasing importance. Here we show that succinic acid, a C4 compound increasingly being produced on a kiloton scale by the microbial fermentation of sugar, can be selectively converted into a variety of important chemicals. Optimal performance in terms of activity, selectivity and reusability is observed with Al2O3-supported Pd nanoparticles, which mediate the selective, hydrogenative lactonization of succinic acid to γ-butyrolactone at >90% selectivity, even at high levels of conversion (<70%). Through a variety of kinetic, spectroscopic and microscopic studies, preliminary structure–activity relationships are presented, and the roles of the reaction conditions, the choice of metal and the nature of the support in terms of guiding the overall process selectivity, are also investigated. On a broader level, these studies demonstrate the suitability of succinic acid to act as a platform for renewable chemical production in future biorefineries.

Highlights

Over the last century, the world has become increasingly dependent on fossil feedstock for the production of fuels, base chemicals, and commodities, including fibers, pharmaceuticals, detergents, plastics, pesticides, fertilizers, lubricants, solvents and much more.[1,2] over 99% of all plastics are produced from chemicals sourced from fossil fuels.[3]
The catalytic hydrogenation of succinic acid (SA) can result in a variety of important commodity chemicals, including THF, GBL and BDO, among others
We show that succinic acid, a C4 compound increasingly being produced on a several kiloton scale by the microbial fermentation of sugar, can be selectively converted into a variety of important chemicals

Summary

■ INTRODUCTION

The world has become increasingly dependent on fossil feedstock for the production of fuels, base chemicals, and commodities, including fibers, pharmaceuticals, detergents, plastics, pesticides, fertilizers, lubricants, solvents and much more.[1,2] over 99% of all plastics are produced from chemicals sourced from fossil fuels.[3]. As can be seen (Table 2), low levels of including the harsh reaction conditions typically required (presence of solvent at high temperature and pressure), and the chelating nature of the oxygenated substrates, such as sugars and acids, which are known to cause leaching and agglomeration of various metallic nanoparticles.[43,44] to gain a preliminary understanding of the reusability properties of 2Pd/Al2O3(COP), recyclability experiments were performed. Detailed reaction coordinate analysis is required before definitive mechanistic hypotheses can be made, these initial vibrational and computational studies clearly indicate that the choice of metal impacts the coordination and the geometry, of SA at the active site at reaction conditions, and likely accounts for the improved selectivity of Pd versus Ru during SA hydrogenation Such computational studies, focused upon generating such a detailed molecular level mechanism, represent the focus of our ongoing work

■ CONCLUSIONS

■ ACKNOWLEDGMENTS

■ REFERENCES