High Catalytic Activity of Pt/Al₂O₃ Catalyst in CO Oxidation at Room Temperature-A New Insight into Strong Metal-Support Interactions

The concept of very strong metal-support interactions (VSMSI) was defined in regard to the interactions that influence the catalytic properties of catalysts due to the creation of a new phase as a result of a solid-state chemical reaction between the metal and support. In this context, the high catalytic activity of the 1%Pt/Al2O3 catalyst in the CO oxidation reaction at room temperature was explained. The catalyst samples were reduced at different temperatures ranging from 500 degrees C to 800 degrees C and characterized using TPR, O-2/H-2 titration, CO chemisorption, TPD-CO, FTIR-CO, XRD, and TOF-SIMS methods. Based on the obtained results, it was claimed that with very high temperature reduction (800 degrees C), nonstoichiometric platinum species [Pt(Cl)O-x] strongly anchored to Al2O3 surface are formed. These species act as the oxygen adsorption sites.