L-proline covalently anchored on graphene oxide as an effective bifunctional catalyst for ketene forming reaction

Graphene oxide supported L-proline (GO–Proline) bifunctional catalyst was prepared by covalent bonds via a succinate spacer. Fourier transform infrared spectrum (FTIR), Raman spectroscopy, scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), high-resolution transmission electron microscopy (HRTEM), and X-ray photoelectron spectroscopy (XPS) were employed to characterize the structure and morphology. The characterizations demonstrated L-proline molecules could be readily introduced to the graphene oxide sheets with homogeneous distributions. Systematic studies demonstrated that it was an efficient, recoverable, and recyclable catalyst in the solvent free ketene forming reaction. Effect of different solvents on its catalytic properties was also investigated.