Nickel-ceria infiltrated Nb-doped SrTiO3 for low temperature SOFC anodes and analysis on gas diffusion impedance

Hussain, A. Mohammed; Høgh, Jens Valdemar Thorvald; Jacobsen, Torben; Bonanos, Nikolaos

doi:10.1016/j.ijhydene.2011.11.087

Cited by 70 publications

(33 citation statements)

References 31 publications

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“…By adding 3% H 2 O in pure H 2 gas flow, arc 4 became indistinguishable. A similar process has been identified as a gas diffusion limitation on Ni–ceria infiltrated STN symmetrical cells, of which resistance decreased substantially upon increased H 2 O content, particularly in the low pH 2 O range. , With negligible thermal activation but strong pH 2 and pH 2 O dependence, the corresponding process of arc 4 seems to be related to the gas diffusion limitation as well …”

Section: Resultsmentioning

confidence: 60%

Insight into the Electrochemical Processes of the Titanate Electrode with in Situ Ni Exsolution for Solid Oxide Cells

Zhang

Tao

et al. 2019

ACS Appl. Energy Mater.

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Perovskite-type titanate with in situ exsolution is one promising electrode material for solid oxide cells because of its distinct properties to resist redox operation, carbon deposition, and sulfur contamination. However, lacking a mechanistic understanding of the electrochemical processes significantly hinders further optimization of the exsolved titanate electrode for its practical application. In this study, the in situ growth of Ni nanoparticles and its effect on the electrode processes was investigated on the Ni-doped Sr0.94Ti0.9Nb0.1O3‑δ electrode for solid oxide cells. Four individual electrode processes were distinguished and determined by equivalent circuit modeling and distribution of relaxation times analysis of the electrochemical impedance data. Correlated with in situ and ex situ characterizations, it is revealed that the electrochemical processes were dominated by the surface reaction process, which was substantially activated by the exsolution of Ni nanoparticles by providing catalytically active sites and accelerating the rate of H2/H2O dissociative adsorption.

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Section: Resultsmentioning

confidence: 60%

Insight into the Electrochemical Processes of the Titanate Electrode with in Situ Ni Exsolution for Solid Oxide Cells

Zhang

Tao

et al. 2019

ACS Appl. Energy Mater.

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“…As titanate-based electrodes exhibit insufficient activity towards anodic reactions, an increasing number of research works have focused on the enhancement of their electrochemical performance. Improved electrochemical activity was reported for Y-doped SrTiO 3 anodes infiltrated with Ni [ 35 , 36 , 37 , 38 ], Ru combined with ceria [ 27 ], or nano-sized Pd catalyst [ 39 ], as well as for (Sr,La)TiO 3 and Sr(Ti,Nb)O 3 anodes infiltrated with Ni [ 40 ], Pd and ceria [ 41 , 42 ], or doped ceria and Cu [ 43 ]. More recently, the exsolution of catalytically active nanoparticles initially dissolved in the crystal lattice of a host oxide attracted great attention as an alternative strategy to enhance the activity of oxide-based electrodes.…”

Section: Introductionmentioning

confidence: 99%

Development of Ni-Sr(V,Ti)O3-δ Fuel Electrodes for Solid Oxide Fuel Cells

2021

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A series of strontium titanates-vanadates (STVN) with nominal cation composition Sr1-xTi1-y-zVyNizO3-δ (x = 0–0.04, y = 0.20–0.40 and z = 0.02–0.12) were prepared by a solid-state reaction route in 10% H2–N2 atmosphere and characterized under reducing conditions as potential fuel electrode materials for solid oxide fuel cells. Detailed phase evolution studies using XRD and SEM/EDS demonstrated that firing at temperatures as high as 1200 °C is required to eliminate undesirable secondary phases. Under such conditions, nickel tends to segregate as a metallic phase and is unlikely to incorporate into the perovskite lattice. Ceramic samples sintered at 1500 °C exhibited temperature-activated electrical conductivity that showed a weak p(O2) dependence and increased with vanadium content, reaching a maximum of ~17 S/cm at 1000 °C. STVN ceramics showed moderate thermal expansion coefficients (12.5–14.3 ppm/K at 25–1100 °C) compatible with that of yttria-stabilized zirconia (8YSZ). Porous STVN electrodes on 8YSZ solid electrolytes were fabricated at 1100 °C and studied using electrochemical impedance spectroscopy at 700–900 °C in an atmosphere of diluted humidified H2 under zero DC conditions. As-prepared STVN electrodes demonstrated comparatively poor electrochemical performance, which was attributed to insufficient intrinsic electrocatalytic activity and agglomeration of metallic nickel during the high-temperature synthetic procedure. Incorporation of an oxygen-ion-conducting Ce0.9Gd0.1O2-δ phase (20–30 wt.%) and nano-sized Ni as electrocatalyst (≥1 wt.%) into the porous electrode structure via infiltration resulted in a substantial improvement in electrochemical activity and reduction of electrode polarization resistance by 6–8 times at 900 °C and ≥ one order of magnitude at 800 °C.

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“…[ 16,17 ] Importantly, the lower degree of sintering (i.e., high surface areas) of the electrocatalysts is retained at the lower operating temperature of SOFCs, enabling overall higher cell performance and stability. [ 18,19 ] Thus, improving the catalytic performance at intermediate temperatures (500 °C–750 °C) is one possible means to enhance the overall SOFC performance. In the present work, we studied the feasibility of running the reforming reaction over NiMo/CZ catalysts at high fuel flow rates and a lower operating temperature of 700 °C.…”

Section: Introductionmentioning

confidence: 99%

Partial Oxidation of Isooctane over Ru‐Promoted Nickel–Molybdenum/Cerium–Zirconium Oxide Catalyst at an Intermediate Temperature for Internal Reforming Solid Oxide Fuel Cell Applications

et al. 2021

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In previous work, nickel–molybdenum (NiMo) nanoparticles supported on cerium–zirconium oxide (CZ) catalyst showed excellent catalytic activity and stability for liquid fuel reforming with an improved coking resistance compared with Ni/CZ. Lowering the temperature of solid oxide fuel cells (SOFCs) below 700 °C is vital, because they can reduce the material costs and thermal stresses of SOFCs. However, the performance of NiMo/CZ is insufficient when operated at temperatures below 750 °C. This work aims to improve the activity and coking resistance of NiMo/CZ at a temperature of 700 °C by adding a minimal amount (0.1 wt%) of Ru. The Ru‐promoted sample shows a high reforming activity for partial oxidation of isooctane at 700 °C. The X‐ray diffraction (XRD) and STEM indicate a smaller Ni crystallite size for NiMoRu/CZ catalyst, which would decrease its tendency to facilitate coke formation. The tubular SOFC with the NiMoRu/CZ as its internal reforming catalyst displays good power density output and performance stability at 200 mA cm−2.

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Nickel-ceria infiltrated Nb-doped SrTiO3 for low temperature SOFC anodes and analysis on gas diffusion impedance

Cited by 70 publications

References 31 publications

Insight into the Electrochemical Processes of the Titanate Electrode with in Situ Ni Exsolution for Solid Oxide Cells

Insight into the Electrochemical Processes of the Titanate Electrode with in Situ Ni Exsolution for Solid Oxide Cells

Development of Ni-Sr(V,Ti)O3-δ Fuel Electrodes for Solid Oxide Fuel Cells

Partial Oxidation of Isooctane over Ru‐Promoted Nickel–Molybdenum/Cerium–Zirconium Oxide Catalyst at an Intermediate Temperature for Internal Reforming Solid Oxide Fuel Cell Applications

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