Hydrogenation of levulinic acid (LA) to γ-valerolactone (GVL) in ionic liquid (IL) mixtures with hydrogen gas in high-pressure CO₂ was studied to demonstrate tuning of product selectivity. Ethyl- or butyl- imidazolium-based cation with Cl, acetate [OAc], diethylphosphate, bis(trifluoro-methanesulfonyl)imide or tetrafluoroborate anion IL mixtures were used as the reaction phase with Pd/C, Pd/Al₂O₃ or Ru/Al₂O₃ commercial catalysts. Experiments were performed with batch reactors using (1 to 5) MPa partial pressure H₂ at nominal pressures of 8 MPa at 110 °C. GVL selectivities as high as 88% at 50% conversion were obtained in [EMIM]Cl-[EMIM][OAc] using 3 MPa partial pressure H₂ in presence of CO₂ at 4 h reaction time. Specific interactions of LA with Cl anion IL and CO₂ with [OAc] anion IL are key to the reaction mechanism. Reaction systems containing Cl anion - [OAc] anion IL mixtures with H₂ gas and CO₂ have wide application to hydrogenation of biomass-related compounds.

研究了在高压CO ₂中用氢气将离子液体（IL）混合物中的乙酰丙酸（LA）加氢成γ-戊内酯（GVL），以证明产物选择性的调节。与Cl，乙酸盐[OAc]，磷酸二乙酯，双（三氟甲烷磺酰基）酰亚胺或四氟硼酸根阴离子IL混合物的乙基或丁基咪唑鎓阳离子用作与Pd / C，Pd / Al ₂ O ₃或Ru的反应相/ Al ₂ O ₃商业催化剂。在间歇式反应器中使用1至5 MPa分压H _{2进行实验}在110°C下8 MPa的额定压力下。在3小时的CO ₂存在下，使用3 MPa分压H ₂在[EMIM] Cl- [EMIM] [OAc]中获得了在50％转化率时高达88％的GVL选择性。LA与Cl阴离子IL和CO ₂与[OAc]阴离子IL的特异性相互作用是反应机理的关键。含有Cl阴离子-[OAc]阴离子IL与H ₂气体和CO _2的混合物的反应系统已广泛应用于生物质相关化合物的加氢。