Vapor-phase hydrogenation of dimethyl oxalate over a CNTs-Cu-SiO ₂ hybrid catalyst with enhanced activity and stability

Hybrids containing carbon nanotubes (CNTs) have attracted considerable attention in heterogeneous catalysis. In this study, a CNTs-Cu-SiO₂ hybrid fabricated by urea-assisted gelation is disclosed to display excellent activity and outstanding long-term stability in the vapor-phase hydrogenation of dimethyl oxalate (DMO). Appropriate hybridization of CNTs with Cu-SiO ₂ results in enhanced Cu dispersion, which is suggested to be one of the key factors in determining the catalytic performance of copper catalysts. Furthermore, the growth of Cu nanoparticles (NPs) during the catalyst activation, DMO hydrogenation and severe aging tests is distinctively inhibited by incorporating CNTs into Cu-SiO₂, leading to remarkably enhanced catalytic stability. The adsorption and activation of hydrogen on this particular hybrid catalyst are also influenced by the CNTs introduction.