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A Multiphase Protocol for Selective Hydrogenation and Reductive Amination of Levulinic Acid with Integrated Catalyst Recovery
Author(s) -
Bellè Alessandro,
Tabanelli Tommaso,
Fiorani Giulia,
Perosa Alvise,
Cavani Fabrizio,
Selva Maurizio
Publication year - 2019
Publication title -
chemsuschem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.412
H-Index - 157
eISSN - 1864-564X
pISSN - 1864-5631
DOI - 10.1002/cssc.201900925
Subject(s) - levulinic acid , chemistry , reductive amination , catalysis , formic acid , selectivity , hydrocarbon , cyclohexylamine , amination , aqueous solution , inorganic chemistry , organic chemistry , methanation
At 60–150 °C and 15–35 bar H 2 , two model reactions of levulinic acid (LA), hydrogenation and reductive amination with cyclohexylamine, were explored in a multiphase system composed of an aqueous solution of reactants, a hydrocarbon, and commercial 5 % Ru/C as a heterogeneous catalyst. By tuning the relative volume of the immiscible water/hydrocarbon phases and the concentration of the aqueous solution, a quantitative conversion of LA was achieved with formation of γ‐valerolactone or N ‐(cyclohexylmethyl)pyrrolidone in >95 and 88 % selectivity, respectively. Additionally, the catalyst could be segregated in the hydrocarbon phase and recycled in an effective semi‐continuous protocol. Under such conditions, formic acid additive affected the reactivity of LA through a competitive adsorption on the catalyst surface. This effect was crucial to improve selectivity for the reductive amination process. The comparison of 5 % Ru/C with a series of carbon supports demonstrated that the segregation phenomenon in the hydrocarbon phase, never previously reported, was pH‐dependent and effective for samples displaying a moderate surface acidity.