Effect of Pt-MOx (M = Fe, Co) interaction on the preferential oxidation of CO over Pt/MOx/TiO2 catalysts prepared by selective electrostatic adsorption

In this work, the catalytic properties of Pt/MOx/TiO2 (M = Fe, Co) catalysts prepared by strong electrostatic adsorption (SEA), were investigated for the preferential oxidation (PROX) of CO in H-2. The SEA method was chosen to achieve a preferential adsorption of Pt onto supported MOx nanoparticles rather than onto the TiO2 surface. XPS, TPR and TEM analysis indicate that the enhancement in the catalytic activity of Pt/MOx/TiO2 is related to a synergetic effect originated by a close contact between Pt and MOx (M = Fe, Co) surface. The results clearly show that Pt supported on CoOx/TiO2 calcined at 300 degrees C, and then reduced at 100 degrees C, exhibits the highest activity, e.g. higher CO conversion and CO2 selectivity, among the supported catalysts studied in this work, that was attributed to a higher concentration of Pt-CoOx moieties over the catalytic surface. This study reports a simple and efficient way to synthesize Pt-promoted catalysts where strong metal-support interactions are highly desired to improve the catalytic performance of selective oxidation reactions.