Recent developments on anodes for direct fuel utilization in SOFC

Abstract

This paper reviews recent work on SOFC anode fabrication at the University of Pennsylvania. In this work, anode fabrication is based on the preparation of a porous YSZ matrix, into which electronic and catalytic components are added by impregnation of the appropriate metal salts. First, the methods used to prepare porous YSZ are described, along with a description of the structures that are obtained. Next, it is demonstrated that cell performance is strongly affected by the methods used to impregnate and pretreat ceria that is added to the porous YSZ. Third, the role of carbonaceous deposits within the anode is discussed. These deposits can lead to improved electronic conductivity that results in improved performance. Finally, the effect of precious-metal dopants, added to ceria to improve the catalytic properties of the anode, is discussed. Pd, Pt, and Rh are shown to give large increases in the performance of the cells, particularly in CH 4 . KeywordsSolid-oxide fuel cell, Direct utilization, n-Butane, Methane, Cu, Yttria-stabilized zirconia, Ceria AbstractThis paper reviews recent work on SOFC anode fabrication at the University of Pennsylvania. In this work, anode fabrication is based on the preparation of a porous YSZ matrix, into which electronic and catalytic components are added by impregnation of the appropriate metal salts. First, the methods used to prepare porous YSZ are described, along with a description of the structures that are obtained. Next, it is demonstrated that cell performance is strongly affected by the methods used to impregnate and pretreat ceria that is added to the porous YSZ. Third, the role of carbonaceous deposits within the anode is discussed. These deposits can lead to improved electronic conductivity that results in improved performance. Finally, the effect of precious-metal dopants, added to ceria to improve the catalytic properties of the anode, is discussed. Pd, Pt, and Rh are shown to give large increases in the performance of the cells, particularly in CH 4 .

A Ceramic-Anode Supported Low Temperature Solid Oxide Fuel Cell

“…The voltage-current curves were recorded by Scribner 890ZV at a scanning rate of 50 mV s −1 . The electrochemical impedance spectra (EIS) were obtained using a Solatron 1260 frequency response analyzer in combination with a Solartron 1287 potentiostat over the frequency range from 0.1 Hz to 10 5 Hz under open-circuit conditions. A scanning electron microscope (SEM, Zeiss) was used to observe the microstructure of the cells.…”

“…7,8 Experimental results have demonstrated that such anode materials are effective in inhibiting carbon deposition or sulfur poisoning. [9][10][11] So far the cell designs are exclusively electrolyte-supported when metal oxide anodes are employed. This design requires relatively thick electrolyte of 300∼500 μm to support the entire cell, leading to significant ohmic resistance.…”

Direct Utilization of Liquid Fuels in SOFC for Portable Applications: Challenges for the Selection of Alternative Anodes

“…Several review papers [104][105][106][107][108][109][110][111] and books [112] have appeared in the last few years on alternative anode materials for SOFC. The review published by Sun and Stimming [113] gives an exhaustive overview of all the anodic compositions considered so far.…”

Influence of composition and Cu impregnation method on the performance of Cu/CeO2/YSZ SOFC anodes

“…In previous studies we have reported on the use of wet impregnation methods for the fabrication of Cu/CeO 2 /YSZ (YSZ = yttria-stabilized zirconia) composite anodes for solid oxide fuel cells (SOFC) [1][2][3][4][5][6][7][8]. In this method of anode fabrication a highly porous YSZ anode matrix is initially prepared by sintering a green YSZ tape which contains pryolyzable pore formers such as graphite.…”