EL (purity >99.5%) was purchased from local company and used without further treatment. The performance of the catalysts was assessed on a fixed bed reactor (i.d. 12 mm, length 500 mm), into which 5 g of catalyst was loaded. Prior to the reaction, the catalyst was reduced at 400 °C in H2 flow. EL and ethanol solvent (EL/ethanol volume ratio was 1/1) were fed into the reactor using an injection pump, and the WHSV flow rate of EL was 0.6 h−1. The reaction temperature was adjusted between 141 °C and 251 °C. The reaction pressure was maintained at 1.0–3.0 MPa. The molar ratio of hydrogen to EL was set as 50 (mol/mol). The hydrogenation products were analyzed using gas chromatography (Agilent 7890) equipped with a flame ionization detector and a capillary column (DB-200). The main products and byproducts were identified by GC-MS method on Agilent 5975C inert XL EI/CI MSD. EL conversion, GVL selectivity, and 2-MTHF selectivity were calculated using the following equations:
The selectivity of other byproducts, such as 2-pentanol, 1-pentanol, 1,4-pentanediol, and ethyl valerate, were calculated using the identical equations.
The selectivity of other byproducts, such as 2-pentanol, 1-pentanol, 1,4-pentanediol, and ethyl valerate, were calculated using the identical equations.