Vanadium-Doped Strontium Molybdate with Exsolved Ni Nanoparticles as Anode Material for Solid Oxide Fuel Cells

Abstract

Vanadium-doped strontium molybdate (SVM) has been investigated as a potential anode material for solid oxide fuel cells due to its high electronic conductivity of about 1000 S cm–1 at 800 °C in reducing atmospheres. In this work, NiO is introduced to SVM with the B-site excess design to induce in situ growth of Ni nanoparticles in the anodic operational conditions. The Ni particles are exsolved from the parent oxide phase as clearly demonstrated with various techniques including X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy, and transmission electron microscopy. The exsolved Ni nanoparticles significantly boost the electrocatalytic activity toward fuel oxidation reaction, improving the peak power density by 160% from 0.21 to 0.56 W cm–2 at 800 °C when using H2 as the fuel, meanwhile reducing the total interfacial polarization resistance by 56% from 0.81 to 0.36 Ω cm2. The Ni-exsolved SVM anode also shows excellent catalytic activity toward H2S-containing and hydrocarbon fuels, providing peak power densities of 0.43, 0.36, and 0.22 W cm–2 at 800 °C for H2-50 ppm H2S, syngas, and ethanol, respectively. In addition, the cell with the Ni-exsolved SVM anode presents a stable power output, indicating that the Ni-SVM is a potential SOFC anode electrocatalyst for various fuels.

Redox-Reversible Electrode Material for Direct Hydrocarbon Solid Oxide Fuel Cells

“…As versatile electrochemical energy conversion devices, solid oxide fuel cells (SOFCs) are capable of converting chemical energy stored in the fuel directly into electricity with fuel flexibility, high efficiency, and environmental friendliness, which has recently attracted a great deal of attention worldwide. − SOFCs have a broad spectrum of potential applications such as portable power, backup power, distributed generation systems, and stationary central power systems. The current focus of SOFCs is primarily on the Ni-based anode, which has advantages of excellent electrical conductivity, high catalytic activity, and low cost.…”

“…3 Co 0.1 Fe 1.3 Mo 0.6 O 7−δ in the I4/mmm space group, and the alloy phase is identified as Co−Fe in the Pm3̅ m space group. The presence as well as composition of the alloy phase can be further verified by XPS analyses (Figure…”

NdBaFe2–xCoxO5+δ Double Perovskites with Exsolved Co–Fe Alloy Nanoparticles as Highly Efficient and Stable Anodes for Direct Hydrocarbon Solid Oxide Fuel Cells

“…32 La 0.9 Sr 0.1 Ga 0.8 Mg 0.2 O 3−δ (LSGM) and Ce 0.8 Sm 0.2 O 1.9 (SDC) powders were prepared via glycine nitrate process. 33 The preparation method of the single cell is consistent with the method previously reported by our group. 34 2.2.…”

“…NdBaCo 2/3 Fe 2/3 Cu 2/3 O 5+δ (NBCFC) was prepared by EDTA–citrate complexation in a previous work . La 0.9 Sr 0.1 Ga 0.8 Mg 0.2 O 3−δ (LSGM) and Ce 0.8 Sm 0.2 O 1.9 (SDC) powders were prepared via glycine nitrate process . The preparation method of the single cell is consistent with the method previously reported by our group …”

Vanadium-Enhanced Intramolecular Redox Property of a Transition-Metal Oxide Molecular Wire

“…Tuning the chemical composition of the molecular wire would affect the redox property. V is a unique element with multivalent, stable coordination states and is a commonly used composition of transition-metal oxides for catalysis, , batteries, − and photocatalysis . The unique redox property of V improves the application performance of the materials. , Therefore, expanding the elemental composition of the transition-metal oxide molecular wire and incorporating V into it would tune the intramolecular redox reaction.…”