Comparison of the Performance of Au, Pt and Rh Nanoparticles Supported on Mn/Alkali Titanate Nanotubes in Formaldehyde Oxidation at Room Temperature

Au, Pd and Rh nanoparticles were supported on Mn/Na2Ti3O7 alkaline titanate nanotubes by the deposition-precipitation with NaOH method. The Pt-Mn/NT alkaline titanate showed outstanding catalytic performance accomplishing complete formaldehyde oxidation at 40 degrees C with apparent activation energy of 27 kJ mol(-1). The following tendency was observed for catalytic activity Pt > Au > Rh. The characterizations revealed the importance of the noble metals in the formation of vacancies and OH groups and their ability to activate the alkaline titanate surface oxygen species, which had an impact on the formation of acid sites (Bronsted and Lewis); another key factor for formaldehyde oxidation was metal dispersion. The presence of OH species facilitated the transformation of formaldehyde adsorbed on the M-Mn/alkaline titanate nanotubes, probably through the reaction with adsorbed O species, which promoted the decomposition of formaldehyde to CO2 at room temperature. [GRAPHICS] .