Effect of Carbon Nanotubes on Activity of Rh-Ce-Mn/SiO2 Catalyst for CO Hydrogenation to Oxygenates

The carbon nanotubes (CNTs)-promoted Rh-Ce-Mn/SiO2 catalysts were prepared by the impregnation method and characterized by X-ray photoelectron spectroscopy (XPS), temperature-programmed reduction, N2 adsorption, X-ray diffraction (XRD), and temperature-programmed desorption of H2 or CO. The catalytic performance of Rh-Ce-Mn-CNTs/SiO2 for CO hydrogenation to oxygenates was investigated. The results of XPS and XRD showed that the introduction of CNTs improved the dispersion of Rh and caused an enrichment of active components on the catalyst surface. Meanwhile, the addition of CNTs modified the interaction between rhodium and other components, and the amount of strongly adsorbed H2 or CO on the surface of the catalyst was increased remarkably. The results of CO hydrogenation showed that the existence of CNTs enhanced the activity of the Rh-Ce-Mn/SiO2 catalyst. Under the specific reaction conditions, the CO conversion was 11.86% and the yield of oxygenates was 336.2 g/(kgh) when the CNTs content was 10%.