Amorphous Pd-Loaded Ti₄O₇ Electrode for Direct Anodic Destruction of Perfluorooctanoic Acid

Abstract

We here present a novel Ti 4 O 7 -based electrode loaded with amorphous Pd clusters that achieve efficient anodic destruction of perfluorooctanoic acid (PFOA), a persistent water pollutant with significant environmental and human health concerns. These amorphous Pd clusters were characterized by the disordered, noncrystalline arrangement of Pd single atoms in close proximity, in contrast to crystalline Pd nanoparticles that have been often employed to tailor the electronic properties of an electrode. We found that the Ti 4 O 7 electrode loaded with amorphous Pd clusters significantly outperformed the Ti 4 O 7 electrode loaded with crystalline Pd particles due to enhanced electron transfer through dominant Pd−O bonds. Combined with the efficient binding of PFOA and its degradation intermediates to the fluorinated electrode surface, this electrode was capable of mineralizing PFOA and releasing fluoride as F − . The reaction pathway was found to proceed without involving reactive oxygen species and therefore was not quenched by common anions in complex natural water systems such as chloride ions.

Defluorination of Omega-Hydroperfluorocarboxylates (ω-HPFCAs): Distinct Reactivities from Perfluoro and Fluorotelomeric Carboxylates

“…Since hydrodefluorination cannot be avoided during UV/sulfite treatment, an oxidative post-treatment is usually required to cleave the remaining C–F bonds in H-rich residues. These mechanistic insights will benefit the development and understanding of PFAS treatment technologies such as photochemical degradation in homogeneous − and heterogeneous systems, − electrochemical degradation, − and plasma treatment, − where reductive and/or oxidative processes are involved. The HO • oxidation results also provide data to compare with similar reaction systems , and achieve a deeper mechanistic understanding.…”

A Two‐dimensional Amorphous Plasmonic Heterostructure of Pd/MoO3‐x for Enhanced Photoelectrochemical Water Splitting Performance

“…As shown in Figure 3c, the pre‐edge energy of the Pd (K‐edge) XANES spectrum for Pd/MoO 3‐x features a obvious shift to higher energy, revealing the positive oxidation state of Pd, compared with that of Pd foil (Pd valance state of zero) [20] . Fourier transform R‐space curves of the Pd K‐edge EXAFS spectra (Figure 3d) show that, one prominent peak exists, centered at 2.5 Å from the Pd−Pd contribution in Pd foil.…”

Ultralong-lifetime Ti/RuO2–IrO2@Pt anodes with a strong metal–support interaction for efficient electrochemical mineralization of perfluorooctanoic acid

“…PFOA is chemically stable and is resistant to many traditional techniques due to its strong C–F bond and high oxidation potential, but recently electrochemical oxidation has been proved to be an effective method for degrading PFOA in an aqueous solution. 3,52 The electrochemical oxidation reactivity of the Ti/RuO 2 –IrO 2 @Pt electrode to PFOA was evaluated in this research, as shown in Fig. 4.…”

“…In recent years, electrochemical oxidation technology has attracted great attention in wastewater purification applications, and as a versatile approach it is frequently used to degrade recalcitrant and toxic organic pollutants, especially perfluorinated compounds. 1–4 The electrode material is the key to optimizing the electrochemical oxidation processes, which directly affects the oxidation efficiency, reaction mechanism, and mineralization degree of organic pollutants on the electrode surface. 5,6 An ideal anode material should have several properties: (i) high electrocatalytic activity for degrading organic pollutants, (ii) high stability under anodic polarization conditions, and (iii) low manufacturing cost and long service lifetime.…”