Co-Cr composite oxides efficiently catalyzed transfer hydrogenation of α, β-unsaturated aldehydes via N-doped carbon and interfacial electron migration

Abstract

We present a simple catalyst preparation route, that is spinel-structured CoCrOx (1:2) loaded on N-doped carbon (CoCrOx (1:2)-CN). The as-synthesized CoCrOx (1:2)-CN catalyst promoted catalytic hydrogen transfer (CTH) of cinnamaldehyde (CMA), affording cinnamyl alcohol (CMO) yield as high as 95.3% under mild reaction conditions. There are several reasons for the high yield of CMA: (a) Through interfacial electron migration and N-doped carbon, the acidity and basicity of mesoporous CoCrOx (1:2)-CN catalyst were enhanced, thereby achieving optimal acid-base synergy. (b) Kinetic studies indicated that spinel-structure and N-doped carbon could increase the reaction rate and achieve a low activation energy (69.2 kJ/mol). (c) DFT calculations revealed that both pyridyl-N and pyrrolyl-N doping lowered the energy barrier for adsorption and desorption of reactants resulting in improved catalytic activity. In addition, the CoCrOx (1:2)-CN catalyst showed good reusability.