Nickel–Iron/Gadolinium‐Doped Ceria (CGO) Composite Electrocatalyst as a Protective Layer for a Solid‐Oxide Fuel Cell Anode Fed with Biofuels

Abstract

The performance and reliability of a commercial solid‐oxide fuel cell (SOFC) with the anode coated by a protective catalytic layer is demonstrated. Physico‐chemical and electrochemical characterizations of a Ni–Fe/gadolinium‐doped ceria (CGO) electrocatalyst forming the protective layer are reported. The anode layer was prepared by using a procedure that favors the interaction between Ni and Fe. Power densities approaching 0.3 W cm−2 for the SOFC cell fed with dry organic fuels were obtained. A time test was performed in the presence of a large flow rate of dry organic fuels under operating conditions (0.8 V) showing appropriate fuel flexibility for the device. The resistance to sulfur contamination was verified by feeding increasing amounts of H2S. The cell showed only moderate performance losses until 80 ppm of sulfur contaminant.

The Effect of Ni-Modified LSFCO Promoting Layer on the Gas Produced through Co-Electrolysis of CO2 and H2O at Intermediate Temperatures

“…Furthermore, the addition of a coating layer on the fuel electrode does not imply any strong change in the manufacturing chain of cells and stacks. The use of cermets (i.e., a combination between metallic and ceramic phases) is the preferred approach, owing to the physico-chemical compatibility between these materials and the fuel electrode of solid oxide cells (SOCs) [32][33][34].…”

Lanthanum Ferrites-Based Exsolved Perovskites as Fuel-Flexible Anode for Solid Oxide Fuel Cells

“…An alternative strategy for SOFC systems’ simplification, which has been quite recently adopted, consists of the use of a functional layer coated on the external side of Ni-YSZ anodes [ 32 ]. Due to the favorable electronic properties, Ni alloys in combination with doped ceria electrolyte have been widely investigated to replace bare Ni [ 33 , 34 , 35 ]. The specific advantage relies on a breaking effect of the crystallographic arrangement of Ni atoms, which is responsible for the cracking mechanism of hydrocarbons [ 36 , 37 ].…”

“…This effect has been achieved by the inclusion of a different transition metal, not adsorbing carbon, into the reticular scaffold of Ni. The metals selected for this inclusion were somehow inert toward the cracking reaction (e.g., Cu) [ 33 ] or capable of modifying the surface electronic density and the lattice distances of the regular Ni–Ni crystallographic network (e.g., Co) [ 34 ], or a combination of all these effects (e.g., Fe) [ 35 ]. Then, a further optimization has been achieved by adopting different synthesis methods with the aim of improving the homogeneity of the solid solution and consequently reducing the probability of Ni–Ni bonds’ occurrence on the surface [ 37 ].…”

A Mini Review on Lanthanum Ferrites-based Exsolved Perovskites as Fuel-flexible Anode for Solid Oxide Fuel Cells

“…An alternative strategy for SOFC systems simplification, quite recently adopted, consists on the use of a functional layer coated on the external side of Ni-YSZ anodes [30]. Due to the favourable electronic properties, Ni alloys in combination with doped ceria electrolyte have been widely investigated to replace bare Ni [31][32][33]. The specific advantage relies on a breaking effect of the crystallographic arrangement Ni atoms which is responsible for the cracking mechanism of hydrocarbons [34,35].…”

“…The metals selected for this inclusion were somehow inert towards the cracking reaction (e.g., Cu) [31] or capable to modify the surface electronic density and the lattice distances of the regular Ni-Ni crystallographic network (e.g., Co) [32], or a combination of all these effects (e.g. Fe) [33]. A further optimization has been then achieved by adopting different synthesis methods with the aim to improve the homogeneity of the solid solution and consequently to reduce the probability of Ni-Ni bonds occurrence on the surface [35].…”