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 °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 ≈18–20 nm in PtY and ≈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 H2 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 + O2) during the CO oxidation particularly over PtFeY. In presence of water, the amount of CO2 adsorbed over PtFeY is ≈5 and ≈600 times more than that of water free reaction over PtFeY and PtY catalysts, respectively.

Promotion of PtY with Fe oxide and addition of H2O with O2 to the surface of the prepared catalysts increase the activity of the prepared catalysts.Figure optionsDownload high-quality image (154 K)Download as PowerPoint slideHighlights
► Preparation and characterization of PtY and PtFeY catalysts by ion exchange method.
► In situ FTIR studies of CO oxidation, WGS over as prepared and reduced catalysts.
► Study the effect of addition of trace amount of water on the oxidation of CO with O2.
► Addition of H2O and/or H2O + O2 enhanced CO removal over Fe-free and Fe-promoted PtY.
► Admission of (CO + O2 + H2O) mixture increased the adsorbed amount of CO2 over PtFeY.