Improvement of solid oxide fuel cell performance by a core‐shell structured catalyst using low concentration coal bed methane fuel

Abstract

A core-shell structured catalyst Ni-BaO-CeO 2 @SiO 2 (@NBC; 7.87% Ni content) with high catalytic activity and thermal stability is prepared and utilized for partial oxidation of methane. The catalyst is introduced into the Ni-8 mol% Ystabilized ZrO 2 anode of a conventional solid oxide fuel cell (CC) by direct spraying (denoted as P-@NBC//CC) and indirect loading as an independent catalyst layer (denoted as Y-@NBC//CC) to improve the coking resistance and cell stability when low concentration coal bed methane is used. At 800 C, the maximum power density of P-@NBC//CC and Y-@NBC//CC increases bỹ 26.8% and 32.8%, respectively, over that of CC (0.63 W cm −2 ). At a discharge current of 0.16 A at 800 C, the voltage of CC drops to 0 V after 16 hours. In contrast, the voltage of P-@NBC//CC decreases from 0.8 to 0.6 V within 30 hours, and that of Y-@NBC//CC decreases from 0.8 to 0.7 V over 180 hours.The manner of loading of the catalyst layer has a significant effect on the cell stability. The indirect loading mode as an independent catalyst layer has an advantage over the direct spraying method. The postmortem microstructure of the cell reveals that direct spray loading on the anode surface allows the catalyst particles to penetrate into the anode layer and blocks the anode pores, resulting in a lower porosity and higher diffusion resistance. K E Y W O R D Scatalyst layer, coking resistance, methane containing fuels, solid oxide fuel cell

Review and Outlook on the Utilization of Low-Concentration Coalbed Methane for Power Generation by Solid Oxide Fuel Cells

“…The effects of different factors, including gas composition, temperature, current density, and loading mode of the catalytic layer, on the cell performance of the SOFC utilizing low-concentration CBM were analyzed through a large number of experiments. ,, In addition to CH 4 , there is a certain amount of other gas components in low-concentration CBM, such as oxygen, nitrogen, etc. Some studies have found that O 2 in low-concentration CBM can alleviate carbon formation in the SOFC anodes through oxidation reactions; however, it is generally important not to have more than 5% oxygen in fuels, because excessive oxygen content can cause non-electrochemical oxidation and Ni oxidation, , which will lead to a decline in the cell performance.…”

Utilization of Thermocatalysts in Solid Oxide Fuel Cells (SOFCs) Fed with Hydrogen-Rich Fuels: A Mini-Review

“…The DIR-SOFC anode possessed a lower porosity and higher diffusion resistance due to the blockage of anode pores caused by penetrated catalyst particles. 62 However, Fu et al analyzed the differences in electrical performance and temperature distribution between DIR-SOFC and IIR-SOFC by exampling methane-fueled SOFC via experiments and numerical simulations. 63 The results showed that the IIR-SOFC just changed the location of methane reforming as compared to the DIR-SOFC, and the total amounts of H 2 and CO produced were almost the same in these two modes.…”

“…Yan et al pointed out that the loading modes of the thermocatalyst significantly affected the SOFC stability. The DIR-SOFC anode possessed a lower porosity and higher diffusion resistance due to the blockage of anode pores caused by penetrated catalyst particles . However, Fu et al analyzed the differences in electrical performance and temperature distribution between DIR-SOFC and IIR-SOFC by exampling methane-fueled SOFC via experiments and numerical simulations .…”

Features of the electrochemical reaction of hydrogen oxidation on the composite SrFeO 3 ‐based anode for a protonic ceramic fuel cell

“…Ni‐ceramic composites are traditionally applied as anodes for SOFCs and PCFCs 19‐23 . They exhibit good electrochemical performance and catalytic activity toward hydrogen oxidation reaction.…”

“…Ni-ceramic composites are traditionally applied as anodes for SOFCs and PCFCs. [19][20][21][22][23] They exhibit good electrochemical performance and catalytic activity toward hydrogen oxidation reaction. However, these anodes have several disadvantages, such as degradation in the atmosphere with high water content.…”