Monolithic TiO2-CeO2 and Pt/TiO2-CeO2 @VUKOPOR®A foams in oxidation of dichloromethane and methanol

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61989100%3A27710%2F25%3A10258206" target="_blank" >RIV/61989100:27710/25:10258206 - isvavai.cz</a>

Result on the web

<a href="https://drive.google.com/drive/folders/1Zqjhb1DcScKOnAqj8WKOsuwLQql8yEhC" target="_blank" >https://drive.google.com/drive/folders/1Zqjhb1DcScKOnAqj8WKOsuwLQql8yEhC</a>

DOI - Digital Object Identifier

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Result language

angličtina

Original language name

Monolithic TiO2-CeO2 and Pt/TiO2-CeO2 @VUKOPOR®A foams in oxidation of dichloromethane and methanol

Original language description

INTRODUCTIONDichloromethane and methanol, solvents widely used in chemical and pharmaceutical industry, belong to the group of volatile organic compounds (VOCs). Both represent a produced large-volume harmful liquid waste from production processes, which needs to be effectively disposed. Considering the development of forms of catalysts for combustion processes, the monolithic form is preferred prior to the granulated form for industrial applications. The main aim of this study was to prepare the monolithic form of catalysts, namely TiO2-CeO2 and Pt/TiO2 CeO2 catalytic layers deposited on inert open-cell VUKOPOR®A ceramic foam (LANIK, s.r.o.), investigate their catalytic performance (activity and selectivity) in dichloromethane (Cl-VOC) and methanol (oxygenated VOC) oxidation, and evaluate their application potential via critical judgement with other studied commercial or laboratory prepared monolith-based catalysts.EXPERIMENTALTiO2-CeO2@VUKOPOR®A foam and Pt/TiO2-CeO2@VUKOPOR®A foam were prepared via using a simple reverse micelles-assisted sol-gel method, dip-coating and calcination. Catalytic foams were examined in oxidation of two VOCs - dichloromethane and methanol. The catalytic performance of foams was studied in the combustion reactor unit with calibrated online FTIR for dichloromethane oxidation in the temperature range of 100−500°C, for methanol oxidation in the range of 45−400°C, at the space velocity (GHSV) of 11, 600 h−1 which corresponds close to industrial scale conditions.RESULTS AND DISCUSSIONIn dichloromethane oxidation, Pt/TiO2-CeO2@VUKOPOR®A foam showed improved CO2 selectivity compared to TiO2 CeO2@VUKOPOR®A foam while their activity and HCl selectivity were comparable. The catalyst acidity/acid sites play the key role in adsorption of dichloromethane on catalyst surface and C-Cl bonds rupture affecting the HCl and Cl2 yield, the reducibility/reducible centers are key in deep oxidation of C-H from by-products and oxidation of CO to CO2, affecting CO2 yield (1, 2). Impregnated PtOx species were responsible for higher reducibility of the Pt/TiO2-CeO2@VUKOPOR®A foam leading to higher CO2 selectivity. In methanol oxidation, Pt/TiO2-CeO2@VUKOPOR®A foam showed improved catalytic activity as well as CO2 selectivity compared to parent TiO2-CeO2@VUKOPOR®A. A weak Lewis acidity and high weak basicity of TiO2-CeO2 support and easily reducible PtOx species in the Pt/TiO2 CeO2@VUKOPOR®A foam were responsible for its improved catalytic performance.CONCLUSIONDerived from the comparison with other studied commercial and laboratory prepared monolith-based catalysts it can be stated the investigated Pt/TiO2-CeO2@VUKOPOR®A ceramic foam could be an interesting monolithic candidate for VOCs industrial oxidation. But, some improvements must be still done within the catalyst itself. CuO should be used rather than platinum to ensure higher reducibility and Al2O3 or ZrO2 should be mixed with TiO2-CeO2 to increase medium and strong Brönsted catalyst acidity. Besides that, it is necessary to investigate the long-term stability of the developed catalytic foam.REFERENCES1. S. Cao et. al, J Colloid Interf Sci, 463, 233-241( 2016)2. S. Cao et.al, Chem Eng J, 290, 147-153 (2016)

Czech name

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Czech description

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Type

O - Miscellaneous

CEP classification

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OECD FORD branch

20500 - Materials engineering

Project

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Continuities

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Publication year

2025

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů