Generation of roughness and deposition of alumina in metallic microchannels

FLAVIA DURAN; PABLO BELZUNCE; LUIS E. CADÚS

San Sebastian

Congreso; ICOSCAR5; 2016

For mobile and portable applications of fuel cell technology, there is a need for compact hydrogen supply systems. Micro-structured reactors bear a number of advantages compared to conventional technology such as fixed catalyst beds. The pressure drop is significantly lowered owing o the laminar flow regime. Heat and mass transfer are improved in microchannels as well [1-3]. Taking into account their mechanical and thermal properties, steels and aluminum are the most frequently used as substrate for monoliths and microchannels reactors. Most of the coated metallic surface prepared without pre-treatment showed poor adherence. In order to improve the adherence between the catalyst coating and the substrate alloy, in austenitic steel such as AISI 304, the oxidation of austenitic stainless steels was employed. This corrosion process can headway under extremereaction conditions. In this work, to prevent this inconvenient, a small layer thickness of Al2O3 is formed onto the microchannels. By this way it should be possible stop the corrosion process and preserve macroroughness that promotes the mechanical anchoring of the catalyst particles.