Core–shell structured Li_0.33La_0.56TiO₃ perovskite as a highly efficient and sulfur-tolerant anode for solid-oxide fuel cells

Abstract

Solid oxide fuel cells (SOFCs), which directly convert chemical energy into electricity, have several advantages, such as fuel flexibility and low emissions. Unfortunately, the performance and stability of SOFCs with state-of-the-art Ni-based anodes are sensitive to impurities, such as sulfur, which is a common component of practical fuels, including natural gas and renewable biogas. The development of sulfur-tolerant anode materials is important for successfully operating SOFCs with sulfur-containing practical fuels. In this study, a core-shell architecture was fabricated from solution infiltration and was evaluated as a sulfur-tolerant anode for SOFCs. For the first time, we used a lithium conductive material, Li 0.33 La 0.56 TiO 3 (LLTO, perovskite oxide), as the shell for anodic reactions. The resulting cell delivered higher electrochemical activities than similar cells, with widely used sulfur-tolerant perovskite anodes. In addition, the cell with the core-shell structured anode demonstrated favorable stability over 70 hours' operation when using 1000 ppm H 2 S-H 2 fuel at 800 C. In contrast, the cell with an anode composed of nanoparticles failed after only 5.5 hours under the same operation conditions. This study offers a new strategy for developing highly sulfur tolerant and efficient anodes for SOFCs.

Tuning layer-structured La0.6Sr1.4MnO4+δ into a promising electrode for intermediate-temperature symmetrical solid oxide fuel cells through surface modification

“…[52][53][54] Compared with hydrogen, methane is more preferable as a fuel because it is abundant in nature. For example, it is the main component of natural gas, coal-bed gas and biogas.…”

Recent Advances in Novel Nanostructuring Methods of Perovskite Electrocatalysts for Energy‐Related Applications

“…As is schematically shown in Figure , a general infiltration process consists of three steps: i) fabrication of porous electrode backbone (Figure a), ii) infiltration of an electroactive phase (Figure b), and iii) thermal treatment to form either discrete nanoparticles (Figure c) or a continuous and conformal thin film (Figure d). In some scenarios, core–shell structures can be produced from infiltration . The infiltrate solution, which contains stoichiometric metal precursors mixed with certain complexing agents and surfactants, can be manipulated to allow control over the morphology of the resultant infiltrate/backbone.…”

“…Besides the electrocatalytic activity, the durability and coking/sulfur resistance of the infiltrated perovskite anode are also critical, and rational design is needed to address this issue. Wang et al proposed a core–shell structured anode comprising an catalytically active perovskite‐type Li 0.33 La 0.56 TiO 3 (LLTO) shell coated on a porous and stable Sm 0.2 Ce 0.8 O 1.9 (SDC) core for use in SOFCs operating on H 2 S‐containing fuels . This core–shell structured LLTO anode showed an excellent electrochemical activity for H 2 oxidation and the cell with LLTO thin‐film anode displayed an outstanding operational stability in 1000 ppm H 2 S–H 2 , much superior to that of the SOFC with LLTO nanoparticles infiltrated anode.…”

Room‐Temperature Synthesis of High‐Entropy Perovskite Oxide Nanoparticle Catalysts through Ultrasonication‐Based Method

“…[10] More recently,J iang et al extended the HEMO study to include perovskite-type oxides with six and seven metallice lements. Although there are evidences of sulfur-tolerant and high-surface area conventional perovskites in literature, [15,18,19] their comparative inferior catalytic activity has so far remained the most important limiting factor for their practical application.T he traditional solidstate reaction and solution-mediated processes commonly used for the synthesis of high-entropy materials at somes tage requirec alcination at extreme temperature, which causes nucleationo fn anoclusters and more particleg rowth. Although the particle size distribution of the synthesized perovskites was not reported, several studies have demonstrated that such extreme temperatured uring the synthetic process causes coagulation of grain boundaries, leadingt ot he formation of clumps, and consequent reduction in the available surfacea rea for reactions.…”

“…[16] In 1975, Gallagher et al reported the use of perovskites as potentialr eplacement for noble-metal-based catalystsi na utomotive exhaust systems. Although there are evidences of sulfur-tolerant and high-surface area conventional perovskites in literature, [15,18,19] their comparative inferior catalytic activity has so far remained the most important limiting factor for their practical application.T he traditional solidstate reaction and solution-mediated processes commonly used for the synthesis of high-entropy materials at somes tage requirec alcination at extreme temperature, which causes nucleationo fn anoclusters and more particleg rowth. Although there are evidences of sulfur-tolerant and high-surface area conventional perovskites in literature, [15,18,19] their comparative inferior catalytic activity has so far remained the most important limiting factor for their practical application.T he traditional solidstate reaction and solution-mediated processes commonly used for the synthesis of high-entropy materials at somes tage requirec alcination at extreme temperature, which causes nucleationo fn anoclusters and more particleg rowth.…”