A novel Cu-based catalyst supported in chitosan nanoparticles for the hydrogenation of carbon dioxide to methanol : from the optimization of the catalyst performance to the reaction mechanism

Chitosan nanoparticles were used as a support for the Cu-based catalyst to convert carbon dioxide to methanol under mild conditions. A statistically significant model for space-time yield (STY) and selectivity as a function of synthesis-related parameters was achieved, predicting optimal values of pH, Cu and chitosan concentrations to be 9.3, 0.088 M and 0.01 M, respectively. A STY of 92.44 mg g h and a selectivity higher than 90% were obtained. A constant reaction yield was obtained for 140 min and the STY only decreased by 18%. Catalyst's reusability was demonstrated for three cycles with a 20% of STY loss.