Influence of sodium impurities on the properties of CeO2/CuO for carbon monoxide oxidation in a hydrogen-rich stream

Sodium is typically employed as component of bases or salts for precipitating metals during preparation of oxide catalysts. It is normally eliminated during rinsing of the solid precursors. The present work shows however that standard rinsing of the solid precursor of an inverse CeO2/CuO with water at 25 °C is ineffective for eliminating sodium from the catalyst. Post-treatment with water at 45 °C allows the practical elimination of sodium. ICP-AES chemical analysis, SBET measurement, XRD and high resolution TEM are employed for characterization. The consequence of sodium presence is an important decrease in the CO-PROX activity, as supported by operando-DRIFTS.