Direct Observation of Oxygen Dissociation on Non‐Stoichiometric Metal Oxide Catalysts

Huang, Yi‐Lin; Pellegrinelli, Christopher; Wachsman, Eric D.

doi:10.1002/anie.201607700

Cited by 15 publications

(31 citation statements)

References 41 publications

(11 reference statements)

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“…(All temperatures can be seen in Figure S3 in the Supporting Information.) A detailed description of 1:1 IIE can be found in our previous work . A two-step reaction model involving dissociation and incorporation is used to fit 1:1 IIE results, and the best fit results are shown in lines.…”

Section: Resultsmentioning

confidence: 99%

“…Our study mainly focuses on kinetics of the conversion of gaseous reactants to products, paramount to many energy-conversion applications, to gain insights for the mass transport between gaseous oxygen-containing molecules and oxide catalysts. , The schematic diagram for gas-phase isotopic oxygen exchange is shown in Figure . BSCF powder is used to achieve a high surface area for catalytic reactions to occur.…”

Section: Introductionmentioning

confidence: 99%

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Molecular Reactions of O₂ and CO₂ on Ionically Conducting Catalyst

et al. 2018

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The presence of CO2, an unavoidable component in air and fuel environments, is known to cause severe performance degradation in oxide catalysts. Understanding the interactions between O2, CO2, and ion-conducting oxides is critical to developing energy-conversion devices. Here, surface reaction kinetics of Ba0.5Sr0.5Co0.8Fe0.2O3‑δ (BSCF) with the presence of both O2 and CO2 is determined using gas-phase isotope exchange. BSCF actively reacts with CO2, and the incorporation of oxygen from CO2 to the lattice of BSCF is directly observed as low as 50 °C. Above 200 °C, the reaction between CO2 and the BSCF surface dominates and is independent of the oxygen partial pressure. In addition, CO2 competes with O2 for binding to vacancy sites, forming surface intermediate species. Surprisingly, these surface intermediate species offer oxygen to exchange with oxygen in gaseous O2 and CO2, inhibiting the interactions between O2 and the solid surface. This work provides fundamental insight into functioning oxide catalysts, and the results can be applied to the design of improved oxide catalysts.

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Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Molecular Reactions of O₂ and CO₂ on Ionically Conducting Catalyst

et al. 2018

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“…A common approach to reduce cathode polarization is through decreasing particle sizes to nanodimensions, increasing the surface area and the triple phase boundary (TPB) length, resulting in an increase of active sites to enhance the total conversion rates. Another approach is enhancement of the intrinsic material surface catalytic activity through the mechanistic understanding of the ORR. − Notably, among all the sequential electrochemical ORR mechanistic steps, one major energy loss comes from charge transfer between the solid phases (cathode/electrolyte), limiting the overall SOFC performance improvement from those other approaches. ,, …”

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confidence: 99%

“…To determine the CFL surface reaction kinetics, gas phase isotope exchange ,,, was performed on GDC powder with and without Co addition. Because of mass transfer limitation at high temperature, , gas phase isotope exchange experiments were conducted at a relatively low temperature range. Temperature-programmed isotope exchange (TPX) of GDC and Co-GDC is shown in Figure A.…”

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confidence: 99%

Evolution of Solid Oxide Fuel Cells via Fast Interfacial Oxygen Crossover

Pan¹,

Hussain²,

Huang³

et al. 2019

ACS Appl. Energy Mater.

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While there have been significant breakthroughs in new functional cathodes facilitating the oxygen reduction reaction (ORR) for low-temperature solid oxide fuel cells (LT-SOFCs), sluggish oxygen charge transfer across the cathode/electrolyte heterogeneous interface also hinders overall performance. To promote oxygen ion exchange at the interface, a thin layer of cerium oxide decorated by an amorphous cobalt oxide overcoating was introduced to function as a fast oxygen ion transport pathway at the interface. The peak power density (PPD) of the modified cell achieved 767 mW/cm 2 at a low operation temperature of 550 °C, which is almost 3 times the power output of the unmodified cell. Oxygen isotope exchange confirmed that the oxygen reduction active cobalt oxide nanolayer drastically reduced the energy barrier for oxygen transport across the solid−solid interface. Such interface modification successfully demonstrates an effective route to enable fast ORR and oxygen transport across the cathode/electrolyte interface at low temperature.

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“…3,23 Nanostructured materials presenting Pt in any form (single atoms, small clusters made of tens of Pt atoms or Pt NPs) are especially interesting due to their excellent catalytic properties. 24,25 If the enhanced catalytic performance often observed in non-stoichiometric materials is also considered, 26 exploring new ternary systems derived from the incorporation of Pt species into the Cu 2−x Se crystal lattice becomes particularly attractive, potentially improving the overall catalytic activity of the semiconductor domain. However, Pt reacts with copper chalcogenides forming a segregated phase, either as a pure metal or as a CuPt alloy, and no examples have been so far reported on Pt incorporation into the binary Cu 2−x E semiconductor lattice.…”

Section: Introductionmentioning

confidence: 99%