Koordination

Frese, Erich; Graumann, Matthias; Theuvsen, Ludwig

doi:10.1007/978-3-8349-7103-6_6

Cited by 2 publications

(2 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Once an Ir-Ru mixed oxide is formed in the grain boundary, Ru is stabilized in this location as the RuO 2 is entirely miscible in IrO 2 , 53 as opposed to the metallic Ir-Ru system. The presence of an oxygen gas atmosphere drives adsorbate-induced Ru segregation (3) by the strength of the Ru-O bond relative to the Ir-O bond, 54 and the potential formation of volatile RuO 3 species. However, no pronounced Ru surface enrichment can be observed in the thermally oxidized sample.…”

Section: Validation Of Proposed Experimental Protocolmentioning

confidence: 99%

Probing catalytic surfaces by correlative scanning photoemission electron microscopy and atom probe tomography

et al. 2020

View full text Add to dashboard Cite

The chemical composition and the electronic state of the surface of alloys or mixed oxides with enhanced electrocatalytic properties are usually heterogeneous at the nanoscale. The non-uniform distribution of the potential across their surface affects both activity and stability. Studying such heterogeneities at the relevant length scale is crucial for understanding the relationships between structure and catalytic behaviour. Here, we demonstrate an experimental approach combining scanning photoemission electron microscopy and atom probe tomography performed at identical locations to characterise the surface's structure and oxidation states, and the chemical composition of the surface and sub-surface regions. Showcased on an Ir-Ru thermally grown oxide, an efficient catalyst for the anodic oxygen evolution reaction, the complementary techniques yield consistent results in terms of the determined surface oxidation states and local oxide stoichiometry. Significant chemical heterogeneities in the sputter-deposited Ir-Ru alloy thin films govern the oxide's chemistry, observed after thermal oxidation both laterally and vertically. While the oxide grains have a composition of Ir 0.94 Ru 0.06 O 2 , the composition in the grain boundary region varies from Ir 0.70 Ru 0.30 O 2 to Ir 0.40 Ru 0.60 O 2 and eventually to Ir 0.75 Ru 0.25 O 2 from the top surface into the depth. The influence of such compositional non-uniformities on the catalytic performance of the material is discussed, along with possible engineering levers for the synthesis of more stable and reactive mixed oxides. The proposed method provides a framework for investigating materials of interest in the field of electrocatalysis and beyond.

show abstract

Section: Validation Of Proposed Experimental Protocolmentioning

confidence: 99%

Probing catalytic surfaces by correlative scanning photoemission electron microscopy and atom probe tomography

et al. 2020

View full text Add to dashboard Cite

show abstract

“…In this regard, we envision that the protonation steps need to be optimized for an efficient proton capture in order to promote the formation of intermediates and CO. Thus, we propose to introduce TM nanoparticles (NPs), [7] especially Ni NPs, to promote the water dissociation and the formation of adsorbed hydrogen (H ad ) with a suitable binding energy for accelerating the protonation reaction kinetics, [8] a possibility that has never been explored for ECR catalysis.…”

Section: Introductionmentioning

confidence: 99%

Proton Capture Strategy for Enhancing Electrochemical CO₂ Reduction on Atomically Dispersed Metal–Nitrogen Active Sites**

et al. 2021

View full text Add to dashboard Cite

Electrocatalysts play a key role in accelerating the sluggish electrochemical CO 2 reduction (ECR) involving multi-electron and proton transfer. Herein, we develop a proton capture strategy via accelerating the water dissociation reaction catalyzed by transition metal nanoparticles (NPs) adjacent to atomically dispersed Ni-N x active sites (Ni@NiNCM) to accelerate the proton transfer to the latter for boosting the intermediate protonation step, and hence the whole ECR process. For the rst time, the accelerated protonation process is amply demonstrated experimentally. Aberration-corrected scanning transmission electron microscopy and synchrotron radiation X-ray absorption spectroscopy, together with DFT calculations, revealed that the Ni NPs accelerated the adsorbed H (H ad) generation and transfer to the adjacent Ni-N x sites for boosting the intermediate protonation and the overall ECR processes. This proton capture strategy is highly general, which can be extended to the design and preparation of various highperformance catalysts for diverse electrochemical reactions even beyond ECR.

show abstract

Koordination

Cited by 2 publications

References 0 publications

Probing catalytic surfaces by correlative scanning photoemission electron microscopy and atom probe tomography

Probing catalytic surfaces by correlative scanning photoemission electron microscopy and atom probe tomography

Proton Capture Strategy for Enhancing Electrochemical CO₂ Reduction on Atomically Dispersed Metal–Nitrogen Active Sites**

Contact Info

Product

Resources

About

Koordination

Cited by 2 publications

References 0 publications

Probing catalytic surfaces by correlative scanning photoemission electron microscopy and atom probe tomography

Probing catalytic surfaces by correlative scanning photoemission electron microscopy and atom probe tomography

Proton Capture Strategy for Enhancing Electrochemical CO2 Reduction on Atomically Dispersed Metal–Nitrogen Active Sites**

Contact Info

Product

Resources

About

Proton Capture Strategy for Enhancing Electrochemical CO₂ Reduction on Atomically Dispersed Metal–Nitrogen Active Sites**