Ni-doped TiO2 nanotubes supported Ru catalysts for CO selective methanation in H2-rich reformate gases

Abstract

In this study, Ni-doped TiO2 nanotubes (Ni-TNTs) with increased thermal stability and improved tubular morphology were successfully prepared via a facile hydrothermal method. Detailed characterization results showed that the Ni element was successfully doped into TNTs structures, thereby resulting in increased thermal stability of TNTs, as reflected by the morphology changing from nanoparticles to nanorods and finally to nanotubes with the increase of Ni doping content. After impregnation of Ru, the resultant Ru/Ni-TNTs catalysts showed excellent catalytic performance for CO selective methanation in H2-rich reformate gases for fuel cell applications, which can deep-remove the CO outlet concentration to below 10 ppm at a selectivity greater than 50% over a wide temperature range of 210–285 °C. The reason for the excellent performance of Ru/Ni-TNTs catalyst is mainly due to the increased specific surface area and thermal stability of Ni-TNTs support, the improved dispersion of supported Ru nanoparticles, and the enhanced chemisorption capability for CO.