Electro-Catalytic and Fuel Cell Studies in an Internal Reforming Iso-Octane Fed SOFC Using Cu/CeO₂ Composites As Anodic Electrodes

Abstract

The internal reforming of iso-octane is examined in a solid oxide fuel cell of the type Cu-CeO2/YSZ/Pt. The results show that i-C8H18 is efficiently reformed by H2O to syngas over Cu/CeO2 composites, free of carbon deposits. Apart from iso-octane reforming, the products distribution at open circuit conditions is also influenced by the associated i-C8H18 thermal cracking and catalytic decomposition reactions as well as by the reverse water gas shift and methanation reactions. At closed circuit operation, the prevailing reactions are related to the electro-oxidation of H2 and CO and the co-electrolysis of H2O and CO2, at anodic and cathodic polarization conditions, respectively. AC impedance spectroscopy studies revealed that the cell and electrode resistances are substantially decreased with increasing temperature leading consequently to higher maximum power densities (12.6 mW/cm2, 850oC). The diffusion of charged and/or neutral species at the electrode surface is possibly the rate limiting step during fuel cell operation.

Comparison of Cu and Pt point-contact electrodes on proton conducting BaZr0.7Ce0.2Y0.1O3−

“…Cu-Co-CeO 2 anodes have been shown to be both carbon and sulphur tolerant, and are promising candidates for use in biogas and hydrocarbon applications [152,153]. As an inverse catalyst, CeO 2 particles supported by a metallic Cu-Co phase posses many of the characteristics of excellent electrocatalysts, and can be used to promote reactions such as the water-gas shift, methanol synthesis through CO 2 hydrogenation, as well as the steam reforming of methane and other alcohols [154][155][156].…”

Europium-Doped Ceria Nanowires as Anode for Solid Oxide Fuel Cells

“…Therefore, it is essential to develop SOFC materials with higher conductivity and/or catalytic activity at lower working temperatures (Hibino et al, 2000;Brett et al, 2008;Wachsman and Lee, 2011). Recently, ceria related materials have been widely studied as electrode materials for intermediate temperature SOFCs (IT-SOFCs) for their unique conduction and catalytic properties at around 500-800 • C (Marina et al, 1999;Murray et al, 1999;Goodenough, 2003;Al-Musa et al, 2015;Fan et al, 2017). SOFCs require anodes that have high ionic (O 2− ) and electronic conductivities for quick charge transfer at the triplephase-boundary (TPB) and a high catalytic activity for fuel gas oxidation (Jiang and Chan, 2004).…”

A high-performance Ni-CeO 2 /Ni/Ni-Y 2 O 3 ·ZrO 2 three-layer anode for direct iso-octane feeding of solid oxide fuel cells

“…The evaluation of power generation properties using the three-layer anode at the optimal condition of 950°C with an S/C = 3.0 is shown in figure 6 . The power generation using the three-layer anode is as good as that of other excellent SOFCs directly fed iso-octane [ 5 , 7 , 9 – 11 , 13 , 15 , 16 , 18 , 19 , 25 ]. In addition, figure 7 shows EDS images of the three-layer anode of Ni-CeO 2 /Ni/Ni-YSZ after the evaluation of the power generation properties.…”

“…2,2,4-Trimethylpentane (iso-octane, C 8 H 18 ) is easy to handle because it is a liquid at ambient temperature and easily vapourizes and is a major component of gasoline. For this reason, SOFCs that directly supply iso-octane as a fuel have recently been investigated as power sources for mobile devices and vehicles [ 1 – 25 ]. The SOFCs that directly supply iso-octane are generally operated with a steam reforming method, which extracts reactive species of hydrogen (H 2 ) and carbon monoxide (CO) from the fuel during power generation.…”

“…Furthermore, Marnellos et al . demonstrated that the use of Cu-CeO 2 as an anode catalyst improves the power generation performance of the SOFCs directly fed iso-octane as fuel [ 9 , 16 , 24 , 25 ]. However, compared to SOFCs feeding H 2 or low hydrocarbons as fuels, power generation is still lower and carbon deposition is not completely suppressed.…”