Boosting Fenton-Like Reactions via Single Atom Fe Catalysis

Abstract

The maximization of the numbers of exposed active sites in supported metal catalysts is important to achieve high reaction activity. In this work, a simple strategy for anchoring single atom Fe on SBA-15 to expose utmost Fe active sites was proposed. Iron salts were introduced into the as-made SBA-15 containing the template and calcined for simultaneous decomposition of the iron precursor and the template, resulting in single atom Fe sites in the nanopores of SBA-15 catalysts (SAFe-SBA). X-ray diffraction (XRD), UV–vis diffuse reflectance spectroscopy (UV–vis DRS), high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM), and extended X-ray absorption fine structure (EXAFS) imply the presence of single atom Fe sites. Furthermore, EXAFS analysis suggests the structure of one Fe center with four O atoms, and density functional theory calculations (DFT) simulate this structure. The catalytic performances of SAFe-SBA were evaluated in Fenton-like catalytic oxidation of p-hydroxybenzoic acid (HBA) and phenol. It was found that the single atom SAFe-SBA catalysts displayed superior catalytic activity to aggregated iron sites (AGFe-SBA) in both HBA and phenol degradation, demonstrating the advantage of SAFe-SBA in catalysis.

Microenvironment modulation of single-atom catalysts and their roles in electrochemical energy conversion

“…Recently, via directly loading Fe species on SBA-15 and a subsequent thermal treatment process (Fig. 2B), Sun and co-workers demonstrated the generation of an SBA-15 confined single-Fe atom catalyst (59). Extended x-ray absorption fine structure (EXAFS) fitting results confirm the presence of atomically dispersed O-Fe sites with an average coordination number of 4.5.…”

“…( B ) Illustration of the decoration of single–Fe atom sites on SBA-15, adapted with permission from Yin et al . ( 59 ). ( C ) Typical configurations of the micropore confined isolated [PtCl 6 ] 2− species together with calculated free energies, adapted with permission from Zhang et al .…”

The interaction of surface electron distribution-polarized Fe/polyimide hybrid nanosheets with organic pollutants driving a sustainable Fenton-like process

“…[5][6][7][8] Nevertheless, the widespread use of the Fenton reaction is being limited by its bottleneck problems, including the narrow pH range (pH 2-3) for normal reactions, 9 and the Fe-containing sludge generation due to the rate limitation of electron recycling, 10 which is considered secondary pollution and requires additional treatment processes. To address these problems, various types of heterogeneous Fenton-like materials such as zero-valent transition metals, 11 transition metal oxides, 12,13 supported/doped transition metal solids, [14][15][16] and single atom catalysts 17 were developed. These catalysts have demonstrated to be useful alternatives due to their good separability and the avoidance of Fe-containing sludge production.…”

Intrinsische elektrokatalytische Aktivitätssteuerung von M‐N‐C‐Einzelatom‐Katalysatoren für die Sauerstoffreduktionsreaktion

“…Diese ist das grçßte Problem fürp raktische Anwendungen in PEMFCs.N ähere Untersuchungen zur niedrigen Stabilitätv on Fe-N-C-SACs in PEMFCs ergaben, dass der Abbau von Ionomeren und Membranen hauptsächlich durch Eisen-bezogene Fenton-Reaktionen herbeigeführt wird, bei denen hochreaktive Hydroxyl-und Hydroperoxyl-Radikale über eine Komplexbildungsreaktion der Fe-Stellen mit generiertem H 2 O 2 entstehen. [51] Die zerstçrenden Fenton-Effekte kçnnen fürC o-N-C-SACs geringer sein als fürF e-N-C-SACs,w eshalb die Erstgenannten als ideale Alternative erscheinen. Allerdings zeigen Co-N-C-SACs eine schwächere ORR-elektrokatalytische Aktivität, und so ist hier eine Steigerung der elektrokatalytischen Aktivitätdas Hauptziel.…”