Low Temperature Catalytic Oxidation of Ethanol Using Ozone over Manganese Oxide-Based Catalysts in Powdered and Monolithic Forms

• Published in: Catalysts 2022-02, Vol.12 (2), p.172
• Main Authors: Touati, Houcine, Valange, Sabine, Reinholdt, Marc, Batiot-Dupeyrat, Catherine, Clacens, Jean-Marc, Tatibouët, Jean-Michel
• Format: Article
• Language: English
• Subjects: Air pollution; Aluminum oxide; Carbon dioxide; Catalysis; Catalysts; Catalytic oxidation; Chemical reactions; Chemical Sciences; Cordierite; cordierite monolith support; Ethanol; Hydrocarbons; Indoor air pollution; Low concentrations; Low temperature; manganese oxide; Manganese oxides; Metal oxides; Molybdenum; Monolithic materials; Onboard equipment; Outdoor air quality; Oxidation; Oxidizing agents; Ozone; Palladium; Photocatalysis; Pollutants; Porous materials; Selectivity; TiO2; Titanium dioxide; Vapor phases; VOCs; Volatile organic compounds; Water vapor
• ISSN: 2073-4344; 2073-4344
• DOI: 10.3390/catal12020172

Catalytic oxidation of low concentrations of ethanol was investigated in dry and humid air streams at low temperature (60 °C) over manganese oxide-based catalysts supported on a meso–macrostructured TiO2 using ozone as the oxidant. Ethanol was selected as a representative model VOC present in indoor air, and its concentration was fixed to 10 ppm. For that purpose, a series of Mn/TiO2 powder and monolithic catalysts was prepared, some doped with 0.5 wt% Pd. Whatever the catalyst, the presence of water vapor in the gas phase had a beneficial effect on the conversion of ethanol and ozone. The Pd–Mn/TiO2 catalyst containing 0.5 wt% Pd and 5 wt% Mn exhibited superior oxidation efficiency to the Mn/TiO2 counterparts by increasing ozone decomposition (77%) while simultaneously increasing the selectivity to CO2 (85%). The selectivity to CO2 approached nearly 100% by increasing the amount of catalyst from 20 to 80 mg. In a further step, alumina wash-coated cordierite honeycomb monoliths were coated with the 0.5Pd–5Mn/TiO2 catalyst. Full conversion of ethanol to CO2 without residual O3 emitted (less than 10 ppb) could be attained, thereby demonstrating that the proposed Pd–Mn/TiO2 monolithic catalyst fulfills the specifications required for onboard systems.