Solid Oxide Fuel Cell Anode Materials for Direct Hydrocarbon Utilization

Abstract

Solid oxide fuel cells (SOFC) are highly efficient energy conversion devices with the advantage of directly utilizing hydrocarbon fuels. Starting with a short introduction about the fuel challenges and early achievements in this field, this review paper focuses on advances in oxygen‐ion conducting electrolyte‐based SOFC during the last 15 years. Robust anodes immune to carbon deposition are a prerequisite for direct hydrocarbon SOFC. In this paper, direct hydrocarbon SOFC anode materials are classified into three general categories: Ni‐cermet, Cu‐cermet, and oxide‐based anodes. Oxide anodes are further classified in terms of their crystalline structures, namely fluorite, rutile, tungsten bronze, pyrochlore, perovskite, and double perovskite. Achievements and recent advances on these SOFC anodes are reviewed and discussed. The concluding remarks summarize the pros and cons of direct hydrocarbon SOFC anode materials along with the perspective of future research trends.

Carbon Deposition and Sulfur Poisoning in SrFe0.75Mo0.25O3-δand SrFe0.5Mn0.25Mo0.25O3-δElectrode Materials for Symmetrical SOFCs

“…Also, the considered nonhydrogen fuels usually contain sulfur (in a form of H 2 S), which can irreversibly poison Ni-YSZ cermet anodes. [1][2][3] It may be stated that construction of robust SOFCs with fuel versatility relies upon a development of the anode materials with improved tolerance towards carbon deposition and sulfur poisoning. Mo-containing perovskitetype oxides have shown promise in this respect.…”

“…In the case of well-established Ni-YSZ cermet anode, the performance degradation upon coking arises mainly from a decrease in length of the Triple Phase Boundary (TPB) on the anode, which limits the number of catalytic sites needed for fuel oxidation. 1,2 Furthermore, the deposited carbon may expand and destroy mechanical integrity of the electrode. Also, the considered nonhydrogen fuels usually contain sulfur (in a form of H 2 S), which can irreversibly poison Ni-YSZ cermet anodes.…”

“…Versatile fuel utilization can be an essential factor for future development and commercial adoption of SOFC technology in power generation, for instance, from biogas used as a renewable energy source. 1,2 One of the main challenges with SOFCs running directly on carbon containing fuels, such as syngas, methane/biogas or other hydrocarbons, is carbon deposition occurring on the anode, which results in a significant, and sometimes detrimental decrease of the performance. In the case of well-established Ni-YSZ cermet anode, the performance degradation upon coking arises mainly from a decrease in length of the Triple Phase Boundary (TPB) on the anode, which limits the number of catalytic sites needed for fuel oxidation.…”

Conductivity and redox stability of new double perovskite oxide Sr1.6K0.4Fe1+x Mo1−x O6−δ (x = 0.2, 0.4, 0.6)

“…Carbon deposition on the Ni-based anode when hydrocarbon fuels are used in the SOFCs is a challenge [1,2]. Therefore, it is desired to develop new anode, particularly redox stable anode for SOFCs [3][4][5][6][7][8][9][10]. Double perovskite Sr 2 (TM)MoO 6-d (TM = Mn, Mg, Fe, Co, Ni, Cu, Zn) as potential anode materials for SOFCs has been the subject of a substantial body of research [3,5,8,9,11], and good fuel cell performance has been achieved for Sr 2 MgMoO 6-d [5], Sr 2 MnMoO 6-d [5], Sr 2 CoMoO 6-d [12] and Sr 2 FeMoO 6-d [13] anodes; of these compounds, only Sr 2 MgMoO 6-d (SMMO) has been proven to be redox stable [14].…”

Meso-Scale Phase-Field Modeling of Microstructural Evolution in Solid Oxide Fuel Cells

“…With up to 60% energy efficiency and a life expectancy of 40,000 hours, the SOFC has emerged as an ideal candidate to meet the energy challenges of the modern world. [1][2][3] However, the commercialization of SOFC is hindered due to its high operating temperature, manufacturing cost, and structural instability. [4][5][6] Structural evolution of SOFC often leads to the structural failure and shortening of SOFC lifetime.…”