Performance of mix‐impregnated CeO₂‐Ni/YSZ Anodes for Direct Oxidation of Methane in Solid Oxide Fuel Cells

Abstract

CeO2‐Ni/YSZ anodes for methane direct oxidation were prepared by the vacuum mix‐impregnation method. By this method, NiO and CeO2 are obtained from nitrate decomposition and high temperature sintering is avoided, which is different from the preparation of conventional Ni‐yttria‐stabilised zirconia(YSZ) anodes. Impregnating CeO2 into the anode can improve the cell performance, especially, when CH4 is used as fuel. The investigation indicated that CeO2‐Ni/YSZ anodes calcined at higher temperature exhibited better stability than those calcined at lower temperature. Under the testing temperature of 1,073 K, the anode calcined at 1,073 K exhibited the best performance. The maximum power density of a cell with a 10 wt.‐%CeO2‐25 wt.‐%Ni anode calcined at 1,073 K reached 480 mW cm–2 after running on CH4 for 5 h. At the same time, high discharge current favoured cell operation on CH4 when using these anodes. No obvious carbon was found on the CeO2‐Ni anode after testing in CH4 as revealed from SEM and corresponding linear EDS analysis. In addition, cell performance decreased at the beginning of discharge testing which was attributed to the anode microstructure change observed with SEM.

A new nickel–ceria composite for direct-methane solid oxide fuel cells

“…Zhou et al have reported a Y and Yb doubly doped CeO 2 -based anode for direct methane SOFCs with good operating stability [21]. La 2 O 3 and CeO 2 were also proved to be good promoters on Ni-based anodes for methane-fueled SOFCs; these two materials improved the operating stability and coking resistance [22,23]. Another effective and simple way to improve the coking resistance and cell performance when operating on methane fuel is to deposit a catalyst layer over the Ni-based anode [24,25].…”

Carbon deposition behaviour in metal-infiltrated gadolinia doped ceria electrodes for simulated biogas upgrading in solid oxide electrolysis cells

“…Since carbon is a light element, it may prove difficult to separate the carbon that formed during the experiment from the contaminative carbon using EDX analysis. [60] However, the correlation between the Raman data and the microscopy analysis allows assigning the filamentous structures in Fig. 5c and 5d to carbon deposits with reasonable confidence.…”

In situ Raman spectroscopic analysis of the coking resistance mechanism on SrZr0.95Y0.05O3−x surface for solid oxide fuel cell anodes

“…The spectroscopic evidence implies that the -CO 3 groups can potentially be used for carbon removal repeatedly, which can contribute to long-term coking resistance toward hydrocarbon fuels. Interestingly, the coking resistance mechanism of SZY is different from that of Ni-based anode modified by other metal [9][10][11][12][13][14][15][16][17][18] or CeO 2 -based oxide [19][20][21][22][23][24]. The suppression of carbon deposition on Au-, Cu-, or Sn-modified anodes is attributed to the lower catalytic activity for hydrocarbon decomposition or weakened adsorption energy of C on Ni [1,[45][46][47].…”

“…However, the addition of other gases requires extra energy, resulting in a reduction of total energy efficiency. The second strategy is the introduction of an anode catalyst layer (e.g., Ru-CeO 2 [6,7] or Cu 1.3 Mn 1.7 O 4 [8]) or the incorporation of a metal or oxide, such as Au [9,10], Cu [11][12][13][14], Sn [15][16][17][18], CeO 2 [19,20], Y 2 O 3 -or Sm-doped CeO 2 [21][22][23][24], CaO [25], or BaO [26], respectively. These anode catalyst layers or Ni-based anodes modified by metal or oxide incorporation can promote hydrocarbon reforming or removal of deposited carbon, resulting in the enhancement of coking resistance while maintaining high energy efficiency.…”