A green process for high selective conversion of γ-butyrolactone into 1,4-butanediol using supercritical CO2
Carolina S.Costa, Adolfo L. Figueredo, Maitê L. Gothe, Reinaldo C. Bazito, Pedro Vidinha, Camila G.Pereira
The hydrogenation of GBL was studied in an environmentally friendly media using bimetallic nanostructured catalysts of palladium and rhenium supported on silica (PdRe/SiO2). The impact of pressure and temperature on the catalytic performance was evaluated in aqueous media using an experimental design. Additional reactions were conducted solvent free and in supercritical CO2 (scCO2). Temperature was the only variable observed to produce a statistically significant effect on GBL conversion and both temperature and pressure were statistically significant to explain the selectivity of BDO. Moreover, the change in reaction media produced a remarkable impact on reaction selectivity. In fact, the selectivity could be completely reversed from THF to BDO in the presence of CO2, showing that scCO2 could be used as a tuner for reaction selectivity towards a given product. In solvent free conditions, THF was the main product (93%), whereas in scCO2 the selectivity completely shifted towards BDO (100%).