Ferrate(VI) Oxidation Mechanism of Substituted Anilines: A Density Functional Theory Investigation

Abstract

Ferrate(VI) (Fe(VI)) is a promising oxidant coagulant and disinfectant for the degradation of organic micropollutants. However, it is hard to elucidate the detailed oxidation mechanism through the current experimental approaches. Substituted anilines (SANs) are important chemical compounds that are widely used in many industries. This paper presents the use of density functional theory (DFT) to understand the oxidation mechanism of SANs by Fe(VI) and the effect of substituents. The calculation results revealed that the primary oxidations of SANs follow the hydrogen atom transfer (HAT) mechanism. Interestingly, the hydroxyl oxygen of HFeO 4− is more reactive than the carbonyl oxygen when reacting with SANs. The formation of the SAN radical is crucial, and all of the products are formed from it. Azobenzene is more favorable to generate the above products. In addition, the obtained results indicate that this kind of substituent has a much greater influence on the reaction rather than the position. Thus, the present study provides a valuable insight into the transformation pathways of SANs in the Fe(VI) oxidation process and the effects of the substituent on oxidation. These results will advance the understanding of Fe(VI) involved in wastewater treatment.

A Comparative Study on the Oxidation Mechanisms of Substituted Phenolic Pollutants by Ferrate(VI) through Experiments and Density Functional Theory Calculations

“…Surprisingly, isomers of dihydroxylated products showed different changing trends of peak areas in LC-MS, indicating that there was more than one mechanism for their generation (Figure S6). According to a previous study, ferrate(VI) may simultaneously attack two adjacent carbon atoms in the aromatic ring through the opening of the two Fe(VI)O bonds. For example, the content changes of BP-8, its monohydroxylated product (P259), and the two isomers of the dihydroxylated product (P275) are illustrated in Figure S5A.…”

Preparation of a novel clay loaded with Fe (VI) for degradation of cefazolin: performance, pathway, and mechanism

“…In recent years, ferrate is widely used as an oxidant additive due to its strong oxidizing activity and excellent occulation capability. Therefore, it is critical to release it slowly into the solution and prolong the reaction time with the target pollutants, in order to maintain the high e ciency for the industrial application of ferrate (Yu et al 2021).…”