Efficient production of methanol and diols via the hydrogenation of cyclic carbonates using copper–silica nanocomposite catalysts

Abstract

Copper–silica nanocomposite catalysts with a uniform Cu dispersion prepared by a precipitation-gel method have been found to be highly efficient in the heterogeneous catalytic hydrogenation of CO₂-derived cyclic carbonates, providing an indirect but practical approach for the transformation of CO₂ to methanol with the co-production of diols under relatively mild conditions. The catalysts possessed remarkable stability in both batch and fixed-bed continuous flow reactors especially after promotion with B₂O₃. The reaction was found to depend sensitively on the Cu particle size, the surface acidity–basicity and the Cu valence of the catalysts. The synergetic effect between balanced Cu⁰ and Cu⁺ sites was considered to play a critical role in attaining high yields of methanol and diols.