CeO2 with three different morphologies of
nanorods (CeO2-r), particles (CeO2-p), and cubes
(CeO2-c) was prepared, and the guaiacol hydrodeoxygenation
over their
corresponding Co-based catalysts was performed at 160–220 °C,
2 MPa, a H2 flow rate of 80 mL/min, and a weight hourly
space velocity of 0.7 h–1. Compared with Co/CeO2-p and Co/CeO2-c, Co/CeO2-r has smaller
Co particle sizes, a higher Brunauer–Emmett–Teller surface
area, and larger amount of Co active centers, oxygen vacancies, and
weak acid sites. These better physicochemical properties for Co/CeO2-r provide more Co active sites for guaiacol hydrodeoxygenation,
favor the adsorption and activation of guaiacol, and contribute to
the cleavage of C–O. Therefore, Co/CeO2-r presents
a maximum guaiacol conversion of 97.1% and the highest yield of cyclohexanol
of 91.7% among these catalysts. The result shows that the shape structure
of CeO2 has an important influence on the guaiacol hydrodeoxygenation
performance over its corresponding catalysts.