PROX reaction over Pt3Sn/Al2O3: Structural investigation by operando DRIFTS
Résumé
PtxSn based catalysts have presented exhibit enhanced activities for preferential CO oxidation (PROX) as compared to analogous Pt catalysts. Yet, often ill-defined PtSn phases present on the catalyst prevent a full understanding of the reaction mechanism and active sites involved. Therefore we used for this study well-defined Pt and Pt3Sn catalysts, obtained by impregnation of pre-formed Pt or Pt3Sn nanoparticles [1]. Our 1% Pt3Sn/?-Al2O3 and 1% Pt/?-Al2O3 catalysts were used in the CO PROX. Experiments were carried out under controlled conditions to obtain intrinsic kinetics. Additionally an investigation of CO adsorption under the reaction mixture was carried out by operando DRIFTS over the samples. An unusual evolution of the adsorbed CO was noted while ramping up the temperature.