Ni-based Alloys as Protective Layer for a Conventional Solid Oxide Fuel Cell Fed with Biofuels

A possible scenario for the future is the utilization of alternative fuels especially those obtained from renewable sources including those derived from biomass. One of the main implications is regarding the consumer’s ability to use an increasingly diverse selection of energy sources. New business models could be especially important in the stationary power sector as fuel cell-based distributed energy systems become an alternative to backup for centrally generated power. Small fuel cells systems, typically less than 10kW, are under consideration for many applications that traditional electric utilities have not supplied widely. In this area, solid oxide fuel cells (SOFCs) may enable new companies to enter the power-generation business as equipment providers or heat and electricity providers. The most common type of SOFC is composed by cells based on yttrium stabilized zirconia (YSZ) as electrolyte Ni-YSZ as anode and La_0.8Sr_0.2MnO₃ (LSM) or La_0.6Sr_0.4Fe_0.8Co_0.2 (LSFCO) as cathode operating at temperatures above 700 °C using H₂ or syngas (H₂+ CO) produced from a reforming process (internal or external).

Bimetallic Ni-based alloys mixed with gadolinium-doped ceria in order to obtain a composite material with mixed electronic-ionic conductivity utilized as a barrier layer in a conventional anode-supported solid oxide fuel cell may represent a practical solution to provide a mitigation of the degradation reactions occurring during the feeding of biofuels.

In this communication, we report few guidelines for the preparation of catalysts having proper behaviour for the utilization as protective layer. Complete physico-chemical characterization and electrochemical investigation of Ni_0.5M_0.5(M=Cu, Co, Sn, Zn, Fe) will be discussed.

Acknowledgements

The present work was in part carried out within an Agreement between the Italian Ministry of Economic Development (MSE) and National Research Council (CNR) in the framework of a Research Program for the Electric System (sub-activity: Development of materials and components, design, demonstration and optimization of FC systems for co-generative applications) and in part carried out in the framework of the Research Program promoted by the Brazialian “Conselho Nacional de Desenvolvimento Científico e Tecnológico“ entitled “Ciência sem Fronteiras”  processo nº 402180/2012-7.

S. C. Zignani wants to thank CNPq for the grant n. 238319/2012-1.

R. M. Reis wants to thank FAPESP for the grant n. 2014/04100-2.

The authors also acknowledge the Italian Ministry of Research and Education for the financial support of the BIOITSOFC project within the program "PROGRAMMI DI RICERCA SCIENTIFICA DI RILEVANTE INTERESSE NAZIONALE- PRIN PROGRAMMA DI RICERCA - Anno 2010-2011 - prot. 2010KHLKFC"