Crystal plane effects of CeO2 on supported cobalt and its catalytic performance for Fischer-Tropsch synthesis

Abstract

The exposing planes of carrier play an essential role in determining the exposing planes and catalytic performance of supported metal catalysts. In this work, Co3O4 nanoparticles were supported on the CeO2 nanorods, nanocubes, and nanopolyhedrons, with dominantly exposing CeO2 (110), (100), and (111) planes, respectively. High resolution transmission electron microscope graphs clearly confirmed that CeO2 has obvious crystal selection effects on supported cobalt, the corresponding supported Co3O4 dominantly exposed (220), (111), and (311) planes, respectively, and the reduced Co dominantly exposed (10–11), (0001), and (111) planes, respectively. Their catalytic behaviors for Fischer–Tropsch synthesis (FTS) were studied in detail, and the optimal catalytic performance was obtained over the cobalt catalyst supported on CeO2 nanorods, mainly due to its exposed Co (10–11) plane with low reaction barrier (-0.83 eV) after reduction. The laser Raman spectra, X-ray photoemission spectroscopy, temperature-programmed reduction, and in situ CO Fourier transform infrared spectroscopy further confirmed the effects of carriers with exposing different planes on the supported cobalt catalysts, explaining the reason for the significantly differences in FTS catalytic performance.