Solid oxide fuel cells (SOFCs), which can directly convert chemical energy stored in fuels into electric power, represent a useful technology for a more sustainable future. They are particularly attractive given that they can be easily integrated into the currently available fossil fuel infrastructure to realize an ideal clean energy system. However, the widespread use of the SOFC technology is hindered by sulfur poisoning at the anode caused by the sulfur impurities in fossil fuels. Therefore, improving the sulfur tolerance of the anode is critical for developing SOFCs for use with fossil fuels. Herein, a novel, highly active, sulfur‐tolerant anode for intermediate‐temperature SOFCs is prepared via a facile impregnation and limited reaction protocol. During synthesis, Ni nanoparticles, water‐storable BaZr0.4Ce0.4Y0.2O3−
δ (BZCY) perovskite, and amorphous BaO are formed in situ and deposited on the surface of a Sm0.2Ce0.8O1.9 (SDC) scaffold. More specifically, a porous SDC scaffold is impregnated with a well‐designed proton‐conducting perovskite oxide liquid precursor with the nominal composition of Ba(Zr0.4Ce0.4Y0.2)0.8Ni0.2O3−
δ (BZCYN), calcined and reduced in hydrogen. The as‐synthesized hierarchical architecture exhibits high H2 electro‐oxidation activity, excellent operational stability, superior sulfur tolerance, and good thermal cyclability. This work demonstrates the potential of combining nanocatalysts and water‐storable materials in advanced electrocatalysts for SOFCs.
Solid oxide fuel cells (SOFCs) are the most widely used fuel cells due to their excellent fuel flexibility, high efficiency and low emissions. Although the liquid fuels are easier to handle and transport than hydrogen, their direct use in SOFC leads to serious performance deterioration because of the coke formation on the traditional Ni‐based cermet anodes. In this review, the advances in the development of coking resistant anodes and the new liquid fuels such as oxygenated hydrocarbons to solve the problem of coke formation with Ni‐based anodes are summarized. It is concluded that Ni‐based cermets are still the most promising anode materials and some targeted modifications are needed to improve the coking resistance. Several strategies to improve the coking resistance of Ni‐based anodes are highlighted. The aim of this review is to provide some helpful guidance and potential directions for the future design of anodes for SOFCs utilizing liquid oxygenated hydrocarbon fuels directly.
Summary
The use of low‐rank coal in a clean and efficient manner is a major challenge facing the current coal technology. A high‐sulfur coal with 4.5 wt% sulfur is chosen to examine the compatibility of the pristine coal and the purified contrast with a solid oxide fuel cell (SOFC) with nickel cermet anodes. Desulfurization of the pristine coal is performed by molten caustic leaching method with a removal ratio of 80%. Analyses of the physicochemical properties of coal samples indicate that the purified coal has a more favorable structure and higher Boudouard reactivity, which is suitable as a fuel for fuel cells. The assessment of electrochemical performance reveals that the purification treatment not only makes the peak power density of SOFCs improve from 115 to 221 mW cm−2 at 900°C but also extends their durability from 1.7 to 11.2 hours under a current density of 50 mA cm−2 at 850°C with a fuel availability increasing from 6.25% to 40%. The postmortem analyses show that far less deposited carbon and nickel sulfide are observed on the anode surface. The fuel‐based investigation reveals that the purified coal is a promising fuel for direct carbon fuel cells.
Summary
The pomelo peel char (PC) was prepared and used as fuel for solid oxide electrolyte direct carbon fuel cells with nickel‐yttrium stabilized zirconia anode, thin‐film YSZ electrolyte, and La0.8Sr0.2MnO3 cathode. The power densities of fuel cells operating on PC and catalyst‐loaded PC (PCC) fuels achieved 309 and 518 mW cm−2 at 850°C, respectively, which are among the highest power densities reported in the literature on DCFCs. The PC exhibited superior gasification reactivity than coal char due to its unique reticulated foam carbon structure with a homogeneously distributed inherent catalyst. The stability tests at a current density of 50 mA cm−2 and 825°C indicate that the cell using PC fuel operated in a more stable manner than that using PCC, and the fuel availabilities for PC and PCC were 47.25% and 34.71%, respectively. The results suggest that PC is a promising solid carbonaceous fuel for solid oxide electrolyte direct carbon fuel cells based on its adequate gasification reactivity and high compatibility with the fuel cells.
Recent advances in the development of anode materials for solid oxide fuel cells: Solid oxide fuel cells (SOFCs) attracted numerous attentions due to their fuel flexibility, high efficiency and low emissions. Recent advances in the coking‐resistant SOFCs operated on liquid fuels are reviewed with highlights in the design of high‐performance anodes and new liquid oxygenated hydrocarbon fuels. Cover illustrator: Yijun Zhong. More details can be found in the Review by Wei Wang et al. on page 33 in Issue 1, 2019 (10.1002/ente.201700738).
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