Stabilizing the OOH* intermediate via pre-adsorbed surface oxygen of a single Ru atom-bimetallic alloy for ultralow overpotential oxygen generation

Abstract

Designing an efficient oxygen evolution reaction (OER) electrocatalysts based on single-atom catalysts is a highly promising option for cost-effective alkaline water electrolyzers. However, the instability of the OOH* intermediate and...

Phase-selective active sites on ordered/disordered titanium dioxide enable exceptional photocatalytic ammonia synthesis

“…S5a-d, † there is a gradual increase of Ti 3+ sites with a simultaneous increase of O D /O L ratio for Li-A o /R d (0.21) and Na-A d /R o (0.46) as a function of reaction time, conrming the generation of Ti 3+ with oxygen vacancies during alkali-metal amine treatment. 22 Furthermore, the absence of all possible impurities like EDA (ethylenediamine), alkali ions (Na + ), and chloride (Cl À ) in the samples which may cause exaggerated and erroneous NH 3 yield was conrmed by N 1s, Na 1s, and Cl 2p XPS spectra, respectively, (Fig. S5e-h †).…”

“…23,36 Importantly, some reported papers claimed that oxygen vacancies introduced on catalysts could behave as active sites for water dissociation and boost HER activity. 22,[37][38][39] Hence, it is necessary to examine the HER activity and selectivity over disordered catalysts in a closed system under the same conditions for the NRR (Fig. 3c and Creating oxygen defects on disordered TiO 2 can harvest visible light, however, the excited electrons which are located at deep trap states are unable to be utilized for the NRR because they cannot be excited and migrated thermally to the CB as well as their states are located well below the N 2 /NH 3 redox potential, which makes them inactive for N 2 xation.…”

Engineering Single Atom Catalysts to Tune Properties for Electrochemical Reduction and Evolution Reactions

“…Lee et al. [ 113 ] synthesized Ru single atom catalysts on Co‐Fe bimetallic alloy substrates encompassed by graphitic carbon (Ru SA CoFe 2 /G) via a sol‐gel micelle encapsulation method done in two steps. Such confinement of Ru SACs and Co‐Fe supports within graphitic carbon largely yielded uniformly dispersed Ru SACs visualized by HADDF‐STEM (Figure 7j), marked via bright spots (sites 1 and 2, red circles, Figure 7k) quantitatively evidenced to represent single Ru atoms (sizes ≈2 Å, Figure 7l).…”

“…These calculation results corroborate experimental activity trends, reconciling simulation energetics and mechanisms to better understand experimental outcomes. Synthesizing Ru SAC CoFe bimetallic alloy supports encapsulated in graphitic carbon (G), Lee et al [ 113 ] aspired to minimize overpotentials for O generating reaction steps in OER. The Co and Fe K‐edge XANES spectra of CoFe 2 /G and Ru SA CoFe 2 /G mirrored that of Ru metal foil, implying CoFe supports are strongly metallic.…”

Novel engineering of ruthenium‐based electrocatalysts for acidic water oxidation: A mini review

“…Atomically dispersed metal‐based heterogeneous catalysts have been put forward in the past several years since Zhang group firstly introduced the terminology “single‐atom catalyst (SAC)” in their work of single Pt atoms anchored on FeO x 67,68 . Recently, employments of Ru single atom for OER in acidic electrolyte are explored 10,47,48,69 . In 2019, Cao et al 47 synthesized the single‐atom Ru catalyst (Ru‐N‐C) via pyrolysis of Ru 3+ adsorbed phosphide carbon nitride under argon atmosphere.…”