Hydrogenation Of Ethyl Levulinate Research Articles

A Novel Tannic Acid-Based Carbon-Supported Cobalt Catalyst for Transfer Hydrogenation of Biomass Derived Ethyl Levulinate.

The catalytic conversion of ethyl levulinate (EL) to γ-valerolactone (GVL) is an important intermediate reaction in the conversion and utilization of biomass resources. The development of novel and efficient catalysts is significantly important for this reaction. In this work, using the biomass-derived tannic acid as carbon precursor and the transition metal cobalt as active component, a novel tannic acid carbon supported cobalt catalyst (Co/TAC) was prepared by pyrolysis and subsequent hydrazine hydrate reduction method. The hydrogenation of EL and other carbonyl compounds by hydrogen transfer reaction was used to evaluate the performance of the catalysts. The effects of different preparation and reaction conditions on the performance of the catalysts were investigated, and the structures of the prepared catalysts were characterized in detail. The results showed that the carbonization temperature of the support had a significant effect on the activity of the catalyst for the reaction. Under the optimized conditions, the Co/TAC-900 catalyst obtained the highest GVL yield of 91.3% under relatively mild reaction conditions. Furthermore, the prepared catalyst also showed high efficiency for the hydrogenation of various ketone compounds with different structures. This work provides a new reference for the construction of the catalysts during the conversion of biomass and a potential pathway for the high-value utilization of tannin resource.

High-Performance Ni3P Catalyst for C═O Hydrogenation of Ethyl Levulinate: Niδ+ as Outstanding Adsorption Sites

High-Performance Ni₃P Catalyst for C═O Hydrogenation of Ethyl Levulinate: Ni^δ+ as Outstanding Adsorption Sites

Zirconium tripolyphosphate as an efficient catalyst for the hydrogenation of ethyl levulinate to γ-valerolactone with isopropanol as hydrogen donor

Hydrogenation of levulinic acid and its esters to produce γ-valerolactone (GVL) is an important reaction in the process of biomass valorization. Herein, a series of novel and porous acid–base bifunctional Zirconium tripolyphosphate were successfully synthesized and utilized to catalyze the hydrogenation of ethyl levulinate (EL) to GVL. It was found that Zr-TPPA-3 with a large number of Lewis acid–base sites and a high specific area displayed the highest catalytic activity, a satisfied GVL yield of 93.1% with 99.5% EL conversion was obtained under the optimal reaction conditions. In addition, poisoning experiments revealed that the acid–base sites play a synergistic effect in the hydrogenation of EL to GVL, and finally proposed a plausible reaction mechanism.

Enantioselective hydrogenation of levulinic acid esters in the presence of the RuII-BINAP-HCl catalytic system

The rate of hydrogenation of γ-ketoesters MeCOCH2CH2COOR (R = Et, Pri, But) in the presence of the chiral RuII—BINAP catalyst (BINAP is 2,2′-bis(diphenylphosphino)-1,1′-binaphthyl) greatly increases upon the addition of 5–10 equivalents of HCl with respect to ruthenium. In the hydrogenation of ethyl levulinate, the optically active γ-hydroxy ester initially formed would cyclize by ∼95% to give γ-valerolactone with optical purity of 98–99% ee. When the Ru(COD)(MA)2—BINAP—HCl catalytic system is used (COD is 1,5-cyclooctadiene, MA is 2-methylallyl), complete conversion of the ketoester (R = Et) in EtOH is attained in 5 h at 60 °C under an H2 pressure of 60–70 atm.