Carbon dioxide reforming of methane to synthesis gas over a TiO2-Ni inverse catalyst

TiO2-Ni inverse catalysts were prepared using an atomic layer deposition (ALD) process, and catalytic CO2 reforming of methane (CRM) reactions over the catalysts (either bare Ni or TiO2 coated-Ni particles) were performed using a continuous flow reactor at 800 degrees C. The TiO2-Ni inverse catalyst had a higher catalytic reactivity at the initial stage of the CRM reaction at 800 degrees C compared to that of bare Ni catalysts. Moreover, the high activity of the TiO2-Ni catalyst was maintained over 65 h of the CRM reaction at 800 degrees C, whereas deactivation of the bare Ni surface began within 1 h under the same conditions. Surface analysis using scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and Raman spectroscopy showed that deposition of graphitic carbon was effectively suppressed in the presence of TiO2 nanoparticles on the Ni surface, thereby improving the catalytic activity and stability of the TiO2-Ni catalytic system. We suggest that utilizing the decorative effect of oxide nanoparticles on the surface of metal catalyst has great potential for the development of metal-based catalysts with high stability and reactivity. (C) 2012 Elsevier B.V. All rights reserved.