Essential role of B metal species in perovskite type catalyst structure and activity on toluene oxidation

• Published in: International journal of environmental science and technology (Tehran) Vol. 19; no. 1; pp. 553 - 564
• Main Authors: Yarbay Şahin, R. Z., Duplančić, M., Tomašić, V., Badia i Córcoles, J. H., Kurajica, S.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 2022
• Subjects: Aquatic Pollution; Earth and Environmental Science; Ecotoxicology; Environment; Environmental Chemistry; Environmental Science and Engineering; Original Paper; Soil Science & Conservation; Waste Water Technology; Water Management; Water Pollution Control; Perovskite; Toluene oxidation; Volatile organic chemicals oxidation; B metal effect
• ISSN: 1735-1472; 1735-2630
• DOI: 10.1007/s13762-021-03148-x

The perovskite type materials with transition metals are getting more attention especially as catalysts in total oxidation reaction. This work explores the B metal effect on the catalytic activity of LaBO
3
structured perovskites in total oxidation of toluene. The perovskite type oxides were obtained by Pechini method and characterized by X-ray diffraction, nitrogen adsorption/desorption isotherms, thermogravimetric analysis and differential scanning calorimetry, temperature-programmed reduction (H
2
-TPR), Raman spectroscopy, Fourier transform infrared spectroscopy and particle size analysis. The results showed that LaFeO
3
catalyst contained a single orthorhombic LaFeO
3
phase, while LaMnO
3
contained LaMn
2
O
5
species besides cubic LaMnO
3
phase. Both catalysts show very narrow distributions and average values of 55.59 μm and 51.43 μm for LaMnO
3
and LaFeO
3
, respectively. With regard to the H
2
-TPR profile for the LaMnO
3
, Mn
4+
to Mn
3+
reduction and Mn
3+
to Mn
2+
reduction. Consequently, the redox performance of ABO
3
perovskites was found as mainly driven by the B-site transition-metal element character. According to the catalytic tests, the LaMnO
3
catalyst was more active for toluene oxidation than LaFeO
3
and achieved the lowest light-off temperatures. An excellent agreement between the experimental data and the proposed one-dimensional pseudo-homogeneous model was achieved and corresponding kinetic parameters (estimated rate constants,
k
, activation energies,
E
A
, and frequency factors,
A
r
) were estimated. Lower activation energy was estimated for LaMnO
3
catalyst (84 kJ mol
−1
vs. 99 kJ mol
−1
for LaFeO
3
) confirming that LaMnO
3
catalyst was more active for toluene oxidation under reaction conditions presented in this paper.