Iliopoulou, E.F.; Pachatouridou, E.; Lappas, A.A. Novel Nanostructured Pd/Co-Alumina Materials for the Catalytic Oxidation of Atmospheric Pollutants. Nanomaterials2024, 14, 124.
Iliopoulou, E.F.; Pachatouridou, E.; Lappas, A.A. Novel Nanostructured Pd/Co-Alumina Materials for the Catalytic Oxidation of Atmospheric Pollutants. Nanomaterials 2024, 14, 124.
Iliopoulou, E.F.; Pachatouridou, E.; Lappas, A.A. Novel Nanostructured Pd/Co-Alumina Materials for the Catalytic Oxidation of Atmospheric Pollutants. Nanomaterials2024, 14, 124.
Iliopoulou, E.F.; Pachatouridou, E.; Lappas, A.A. Novel Nanostructured Pd/Co-Alumina Materials for the Catalytic Oxidation of Atmospheric Pollutants. Nanomaterials 2024, 14, 124.
Abstract
Cobalt-doped alumina catalysts were prepared by different methods, applying either the conventional wet impregnation (WI) and/or the advanced spray impregnation (SI), and evaluated as novel oxidation catalysts for CO and MeOH oxidation. The spray impregnation technique aims towards the synthesis of core-shell catalytic nanostructures to secure chemical/thermal stability of the active sites on the catalyst carrier. The catalysts were further promoted with low Pd content (0.5 wt.%) applying either incipient wetness impregnation (DI) or spray impregnation. The results revealed the superior performance of spray impregnated catalysts (Co/γ-Al2O3-SI) for both reactions. The deposition of Co oxide on the outer surface of the alumina particle (SEM images) and the availability of the active Co phase, resulted in the enhancement of Co/γ-Al2O3 catalysts oxidation activity. Pd incorporation increased catalysts reducibility (TPR-H2) and improved the catalysts performance for both reactions. However, Pd incorporation method affected the catalytic performance; as with the SI method the active phase of Co3O4 was probably covered from PdO and was not available for the oxidation reactions. On the contrary, the incorporation of Pd with the DI method resulted in better dispersion of PdO all over the Co/Al catalyst surface, maintaining available Co active sites and better Pd-Co interaction. MeOH desorption studies revealed the methanol oxidation mechanism; Co/Al catalysts promote partial oxidation of MeOH to formaldehyde (HCHO) and dehydration to dimethyl ether (DME), while Pd-based Co/Al catalysts enhance the complete oxidation of methanol to CO2 and H2O.
Keywords
CO oxidation; Methanol oxidation; Spray impregnation; Core-shell; Cobalt oxide; Palladium
Subject
Chemistry and Materials Science, Other
Copyright:
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