Construction of dual active sites on diatomic metal (FeCo−N/C-x) catalysts for enhanced Fenton-like catalysis

Modulating the Electronic Coordination Configuration and d-Band Center in Homo-Diatomic Fe2N6 Catalysts for Enhanced Peroxymonosulfate Activation

“…Meanwhile, the dosing of CBZ did not promote the decomposition of PMS in all systems, indicating that the electron-transfer pathway may not be the dominant in the degradation process. It is well known that methyl phenyl sulfoxide (PMSO) could be specifically oxidized by high-valent iron-oxo via the oxygen-atom-transfer process to form methyl phenyl sulfone (PMSO 2 ) . Compared with the standard PMSO ( m / z = 141.0385 ± 0.0004), an apparent peak with an m / z value of 157.0326 ± 0.0002 ascribed to PMSO 2 was determined in all systems, indicating the existence of high-valent iron-oxo species (Figure S17).…”

“…Notably, a minor peak at a higher R-value (ca. 2.39 Å) was ascribed to the Fe−Fe coordination path, 19,47 suggesting the formation of the diatomic Fe coordination configuration in Fe 2 CN. To further verify the monatomic and diatomic configurations, wavelet transform analysis was conducted to provide powerful resolution in both R and k spaces.…”

“…Hydroxyl ( • OH) and sulfate (SO 4 •– ) radicals have been considered to be the dominant ROS in the Fenton-like reactions. Methyl alcohol (MeOH) was chosen as a quencher for • OH and SO 4 •– [ k MeOH, • OH = 9.7 × 10 8 M –1 s –1 , k MeOH, SO4 •– = 3.2 × 10 6 M –1 s –1 )], while tert -butyl alcohol (TBA) will only capture • OH ( k TBA, • OH = 3.8 × 10 8 M –1 s –1 ). , As revealed in Figure a, neither MeOH nor TBA had obvious inhibition on the degradation of CBZ in the Fe 1 CN/Vis/PMS system, indicating that • OH and SO 4 •– were not the main ROS. When furfuryl alcohol (FFA) as a scavenger for singlet oxygen ( 1 O 2 ) was added to the Fe 1 CN/Vis/PMS system, an apparent inhibition can be observed (decreased from 83.0 to 4.1%), implying that 1 O 2 was the major ROS of Fe 1 CN for the CBZ degradation.…”

“…Despite these advances, some general shortcomings of SACs still need to be overcome, such as finding whether monatomic sites represent the highest intrinsic activity . The construction of diatomic catalysts (DACs) offers another advanced avenue for uplifting the intrinsic activity of SACs, which achieve higher metal loading and more efficient metal site activity. DACs identified as a site with two adjacent metal atoms that can directly or indirectly modulate the activation barrier of key rate-limiting steps .…”

Single–atom catalysts based on Fenton-like/peroxymonosulfate system for water purification: design and synthesis principle, performance regulation and catalytic mechanism

“…Particularly, g-C 3 N 4 is often used as a green carrier and energy storage material in the traditional catalytic field because of its excellent chemical inertness, high specific surface area and a variety of nano multi-level structures. 62 Therefore, this metal–nitrogen coordination SACs also inhibits the leakage of metal ions and reduces the potential risk to the environment, which is ascribed to its coordination field effect, geometric configuration and chemical stability. It also opens up a new way for Fenton-like SACs to develop in the direction of wide pH range and sustainable catalysis.…”