Waste lithium-ion batteries for selective transfer hydrogenation of bio-based ethyl levulinate: Experiments, kinetics and economic assessment

The present research firstly developed the waste lithium-ion batteries as heterogenous catalysts for catalytic upgrading of bio-based ethyl levulinate (EL) into gamma-valerolactone (GVL) using 2-propanol as both the hydrogen source and solvent. The existing acid and basic sites in waste lithium-ion batteries significantly favored the MPV reduction of bio-based EL, wherein 87.4 % GVL yield and low activation energy of 35.2 kJ/mol were achieved. Furthermore, the waste lithium-ion batteries contributed to H-transfer upgrading of a variety of building blocks containing unsaturated groups, such as aldehydes and esters. More gratifyingly, the economic assessment demonstrated that EL-to-GVL transformation via H-transfer manner was preferred as compared with the traditional hydrogenation, in which the total cost for converting 1 kg EL declined by 10.58 $ and overall profit increased by 12.35 $. In addition, the plausible mechanism for H-transfer upgrading of EL into GVL over waste lithium-ion batteries was proposed.