Cu2O nanoparticles supported hydrothermal carbon microspheres as catalyst for propargylamine synthesis

Abstract

Cu2O nanoparticles supported on hydrothermal carbon microsphere (HTC) have been synthesized by hydrothermal synthesis followed by chemical reduction method. The prepared catalyst was used for propargylamine synthesis from the coupling of phenyl acetylene with benzaldehyde and piperidine. In this protocol, biomass derived D-glucose was used as carbon source for the synthesis of carbon microspheres by hydrothermal treatment and CuCl2·6H2O as a copper precursor. The activity of Cu2O@HTC was compared with different catalysts such as CuFe2O4, CuCl2·2H2O, commercial CuO, and Cu2O. Among them Cu2O@HTC exhibited the best activity and selectivity for propargylamine synthesis. The catalyst was well characterized by several analytical techniques such as SEM, XRD, FTIR, TEM, ICP-AES, and XPS analysis before and after 5th reuse. The effect of various parameters was studied including solvent, catalyst loading, mole ratio and temperature of the reaction to achieve the best yield at 60 °C and 1.5 × 10−3 g/cm3 catalyst loading. Notably, Cu2O@HTC was recycled five times and found to be robust.