Journal of Molecular Catalysis A-Chemical, Vol.344, No.1-2, 111-121, 2011
In situ FTIR studies of CO oxidation over Fe-free and Fe-promoted PtY catalysts: Effect of water vapor addition
In the quest of better CO elimination catalysts. Fe oxide was employed to promote platinum supported on HY zeolite. Fe-free and Fe-promoted PtY catalysts were prepared by ion exchange method and calcined at 500 degrees C. The prepared samples were characterized using XRD, FTIR, TEM. CO adsorption and CO-TPD. The particles size calculated from XRD patterns and TEM images was approximate to 18-20 nm in PtY and approximate to 8-15 nm in PtFeY. The CO removal performance over the prepared solids has been investigated by means of in situ technique using FTIR spectroscopy. Platinum surface modified with Fe oxide has a pronounced catalytic activity towards the CO oxidation more than Fe-free Pt containing catalyst. Reduction of the prepared catalysts with H(2) gas prior to admission of gas mixtures increased the catalytic activity more than that of as prepared catalysts. A strong positive water-effect was established when a trace amount of water (more realistic conditions) was added to the gas mixture (CO+O(2)) during the CO oxidation particularly over PtFeY. In presence of water, the amount of CO(2) adsorbed over PtFeY is approximate to 5 and approximate to 600 times more than that of water free reaction over PtFeY and PtY catalysts. respectively. (C) 2011 Elsevier B.V. All rights reserved.