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. 2024 May 9;18(1):83.
doi: 10.1186/s13065-024-01194-3.

MnO2/TiO2-Catalyzed ozonolysis: enhancing Pentachlorophenol degradation and understanding intermediates

Cristian Valdés  1 , Cristina Quispe  2 , Rubén A Fritz  3 , Rodrigo Andler  4 , Jorge Villaseñor  5 , Gina Pecchi  6 , Edgardo Avendaño  7 , Alvaro Delgadillo  8 , William N Setzer  9 , Javad Sharifi-Rad  10
Affiliations

MnO2/TiO2-Catalyzed ozonolysis: enhancing Pentachlorophenol degradation and understanding intermediates

Cristian Valdés et al. BMC Chem. .

Abstract

Pentachlorophenol is a pesticide widely known for its harmful effects on sewage, causing harm to the environment. In previous studies, our group identified adsorption as a crucial factor in catalytic ozonation processes, and subsequent observations revealed the catalyst's role in reducing toxicity during degradation. In this research, we quantified organochlorine intermediates and low molecular weight organic acids generated under optimal pH conditions (pH 9), with and without the catalyst. Additionally, we assessed the reactivity of these intermediates through theoretical calculations. Our findings indicate that the catalyst reduces the duration of intermediates. Additionally, the presence of CO2 suggests enhanced mineralization of pentachlorophenol, a process notably facilitated by the catalyst. Theoretical calculations, such as Fukui analysis, offer insights into potential pathways for the dechlorination of aromatic molecules by radicals like OH, indicating the significance of this pathway.

Keywords: Dechloration; Fukui; MnO2/TiO2; Ozonation; Pentachlorophenol.

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Conflict of interest statement

The authors declare no competing interests.

Figures

Fig. 1
Fig. 1
Catalytic system
Fig. 2
Fig. 2
Degradation of pentachlorophenol in presence of ozone
Fig. 3
Fig. 3
Generation of chlorides in the absence (A) and presence (B) of the catalyst
Fig. 4
Fig. 4
Electronic density distribution of pentachlorophenol by Fukui calculations
Fig. 5
Fig. 5
TTC-1,4-BQ electron density distribution using Fukui calculations
Fig. 6
Fig. 6
TTC electron density distribution by Fukui calculations
Fig. 7
Fig. 7
Distribution of electron density of 2,4-dichlorophenol by Fukui calculations
Fig. 8
Fig. 8
Hydroquinone electronic density distribution by Fukui calculations
Fig. 9
Fig. 9
Distribution of catechol electron density by Fukui calculations
Fig. 10
Fig. 10
Trichloroacetic acid formation in the presence of ozone and catalyst
Fig. 11
Fig. 11
Malonic acid formation in the presence of ozone and catalyst
Fig. 12
Fig. 12
Formic acid formation in the presence of ozone and catalyst
Fig. 13
Fig. 13
Oxalic acid formation in the presence of ozone and catalyst
Fig. 14
Fig. 14
Maleic acid formation in the presence of ozone and catalyst
Fig. 15
Fig. 15
Production of chlorides and accumulation of CO2 in the presence and absence catalyst’s
See this image and copyright information in PMC

References

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