Abstract

A series of substituted La1-xSrxCoO3 perovskites, with XSr = 0.0, 0.05, 0.1, 0.2 were used as catalysts in the liquid hydrogenation of levulinic acid at 250 °C and 5.0 MPa of H2. The solids were analyzed by elemental chemical analysis, XRD, H2-TPR, N2 physisorption at 77 K, NH3-TPD, and XPS. The catalytic activity increased as Sr-substitution increased up to 10 % of Sr. A further increase in Sr-substitution produces a significant decrease in LA conversion. The higher catalytic activity correlated with the highest amount of Co2+ species, whereas the further reduction of the catalytic activity was attributed to segregated phases. Furthermore, it was found that Sr substitution in the A-site changes the reaction mechanism for forming the main reaction product gamma-valerolactone, demonstrating that the substitution of La3+ by Sr2+ modifies the Co3+/Co2+ ratio redox pair. © 2025