Heterogeneously Catalyzed Synthesis of Biogenic N-Dihydroxypropan-2-Pyrrolidone

In this work several solid catalysts are characterized and tested in the reductive amidation of succinic acid and dimethyl succinate with the amine serinol. The reductive amidation is performed in stainless steel autoclaves under elevated hydrogen pressure and yields N-dihydroxypropan-2-pyrrolidone as a product. The product is meant to be polymerized in presence of succinic acid by the industry partner Henkel™, who intends to use the obtained polymer for replacing polyvinylpyrrolidone in laundry detergents formulations. Effective catalysts were prepared, characterized and tested. Each catalyst was analysed with XRD, BET and ICP. The three best performing catalysts, namely Ru/C, RuRe/C (oC) and PtRe/TiO2 (LD), were additionally characterized with NH3-TPD, CO pulse and electron microscopy. Ru/C emerged in tests as the best performing catalyst. This behavior, in disagreement with results obtained in a similar reaction, was put in relation to how the catalysts’ acidity influences the yield of the reaction according to the polarity of the used amine. Lastly, kinetic curves for both succinic acid and dimethyl succinate were recorded, demonstrating how carrying on the reaction for 40h allows to reach a yield of 29% using the substrate succinic acid. During the recording of the kinetic curves ICP analysis were performed in order to test Ru/C stability towards leaching.