AuPd/Fe3O4-based three-dimensional electrochemical system for efficiently catalytic degradation of 1-butyl-3-methylimidazolium hexafluorophosphate

Abstract

Keywords: three-dimensional system AuPd/Fe 3 O 4 ionic liquids kinetic study degradation mechanism A B S T R A C T Ionic liquids (ILs) have been reported to be toxic and harmful to aquatic and terrestrial organisms, thus it is imperative to remove the residual ILs in various effluents. In this work, a three-dimensional (3D) electrocatalytic system with synthesized AuPd/Fe 3 O 4 nanoparticles (NPs) as particle electrodes (PEs) was established for the degradation of typical 1-butyl-3-methylimidazolium ([BMIM]) based ILs. The assynthesized AuPd/Fe 3 O 4 possessed preferable electrochemical properties for in situ supplement of H 2 O 2 and renewable Fe species. This 3D electrocatalytic system exhibited excellent performance with 100% removal rate of BMIM in 90 min under 120 mA, pH 3, and 1 g/L dosage of AuPd/Fe 3 O 4 NPs. Kinetics study revealed that the degradation rule of BMIM well followed the anodic Fenton treatment (AFT) model, in which the variation of the degradation rate was positively correlated with that of dissolved Fe 2+ , while significantly differed from the evolution of H 2 O 2 . Particularly, the appearance of the H 2 O 2 inflection point suggested the optimal effectiveness of AuPd/Fe 3 O 4 -based 3D electrocatalysis. During this electrocatalytic process, the active HO was produced over the AuPd/Fe 3 O 4 PEs, thereby initiated the highly efficient degradation of BMIM into 1-butyl-3-methyl-2,4,5-trioxoimidazolidine, 1-butyl-3-methylurea and N-butyl-formamide as main intermediates. The electrocatalytic stability of the AuPd/Fe 3 O 4 PEs over seven times further indicated the potential applicability for organic wastewater treatment.

Recent Advances in the Direct Synthesis of H2O2

“…The Fenton process, the catalytic formation of hydroxyl and hydroperoxy radicals by the disproportionation of hydrogen peroxide, can be considered one of the most efficient means for the degradation of organic pollutants in wastewater streams at low to moderate concentrations . Numerous studies have investigated the efficacy of H 2 O 2 generated in situ over Pd−Fe based catalysts utilising a range of hydrogen sources such as formic acid, hydroxylamine and hydrazine . Indeed Underhill et al .…”

Environmental Impact of Ionic Liquids: Recent Advances in (Eco)toxicology and (Bio)degradability

“…[89b] Recently, AuPd/Fe 3 O 4 nanoparticles have been used as particle electrodes (PEs) in the electrochemical degradationo fI Ls. [91] The developeds ystem shows promisingr esults for [bmim][PF 6 ], the complete degradation of which is observed within 90 min under optimized conditions. The main intermediates observed by GC-MS are the same as those observed by Zhou in the ZVI/ AC microelectrolysis system, that is, 1-butyl-3-methyl-2,4,5-trioxoimidazolidine in the first step, which affords 1-butyl-3methylurea as an intermediate metabolite, and finally N-butylformamide as the end product.…”

Highly efficient Pd-Fe/Ni foam as heterogeneous Fenton catalysts for the three-dimensional electrode system

“…Thus, modifying the noble metal such as Pd with iron to synthesize composite catalyst should be desirable. For instance, Qin et al [12] synthesized AuPd/Fe 3 O 4 nanoparticles as PEs, and their results showed that…”