Low-Temperature Toluene Oxidation on Fe-Containing Modified SBA-15 Materials

Ivalina Trendafilova; Manuel Ojeda; John M Andresen; Alenka Ristić; Momtchil Dimitrov; Nataša Novak Tušar; Genoveva Atanasova; Margarita Popova

doi:10.3390/molecules28010204

Low-Temperature Toluene Oxidation on Fe-Containing Modified SBA-15 Materials

Molecules. 2022 Dec 26;28(1):204. doi: 10.3390/molecules28010204.

Authors

Ivalina Trendafilova^{1

2}, Manuel Ojeda³, John M Andresen³, Alenka Ristić⁴, Momtchil Dimitrov¹, Nataša Novak Tušar^{4

5}, Genoveva Atanasova⁶, Margarita Popova¹

Affiliations

¹ Institute of Organic Chemistry with Centre of Phytochemistry, Bulgarian Academy of Sciences, Acad. G. Bonchev Str., Bl. 9, 1113 Sofia, Bulgaria.
² Laboratory of Inorganic Materials Chemistry, Namur Institute of Structured Matter, University of Namur, 5000 Namur, Belgium.
³ Research Centre for Carbon Solutions (RCCS), Heriot-Watt University, Edinburgh EH14 4AS, UK.
⁴ Department of Inorganic Chemistry and Technology, National Institute of Chemistry, Hajdrihova 19, 1000 Ljubljana, Slovenia.
⁵ Graduate School, University of Nova Gorica, Vipavska 13, 5000 Nova Gorica, Slovenia.
⁶ Institute of General and Inorganic Chemistry, Bulgarian Academy of Sciences, Acad. G. Bonchev Str., Bl. 11, 1113 Sofia, Bulgaria.

Abstract

Transition metals as catalysts for total VOC oxidation at low temperatures (150-280 °C) are a big challenge nowadays. Therefore, iron-modified SBA-15, AlSBA-15, and ZrSBA-15 materials with 0.5 to 5.0 wt.% Fe loading were prepared and tested for toluene oxidation. It was found that increasing Fe loading significantly improved the rate of oxidation and lowered the temperature of achieving 100% removal of toluene from above 500 °C for the supports (AlSBA-15 and ZrSBA-15) to below 400 °C for 5FeZrSBA-15. The formation of finely dispersed iron oxide active sites with a particle size less than 5 nm was observed on all the SBA-15, AlSBA-15, and ZrSBA-15 supports. It was found that the surface properties of the mesoporous support due to the addition of Al or Zr predetermined the type of formed iron oxide species and their localization on the support surface. Fe-containing SBA-15 and AlSBA-15 showed activity in total toluene oxidation at higher temperatures (280-450 °C). However, 5 wt. % Fe-containing ZrSBA-15 showed excellent activity in the total oxidation of toluene as a model VOC at lower temperatures (150-380 °C) due to the synergistic effect of Fe-Zr and the presence of accessible and stable Fe²⁺/Fe³⁺ active sites.

Keywords: AlSBA-15; SBA-15; VOC removal; ZrSBA-15; iron oxides; toluene oxidation.

Abstract

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