José Rodrigues is a PhD student of Engineering Design and Advanced manufacturing in the framework of the MIT Portugal Program. His work concerns the development of new catalytic surfaces for application clean combustion systems. He is also a researcher at the Combustion Laboratory at the Center for Innovation, Technology and Policy Research (IN+) in Lisbon, Portugal.
This paper describes the stable catalytic combustion on a micro-channel reactor with catalytic walls for low-emission clean combustion applications and explores the feasibility of using catalytically active metal oxides coated on the micro-channel walls as alternative catalytic metals. By means of a catalytic reaction, combustion products may be tuned towards solely H2O and CO2, with near-zero emission of CO and NOx due to complete combustion at low temperatures, in the range of 853K and 1253K. Alternative catalytically active metals to replace Platinum and Palladium as catalysts for the methane combustion reaction are well known and identified. Nickel and cobalt oxides have proven to be good candidates for methane combustion, with low loss of performance, inexpensive and are abundant minerals. The interest on catalytic combustion for water heating applications has been driven by a number of aspects. Catalytic combustors are more fuel flexible than traditional combustors due to the low dependence on the velocity fields, flame speed and mixture quality. The reaction is flameless and stability depends on heat fluxes on the reacting surface and heat transfer from the reactor. Cobalt oxide (Co3O4) synthesis through cobalt hydroxide electrodeposition flowed by annealing treatment on a stainless-steel plate resulted on a very high specific area, with high potential for high catalytic activity rates.
• The catalytic activity of a Co3O4 film produced by electrodeposition was prepared and tested on a micro-channel reactor towards the combustion of methane.
• Electrodeposited Co3O4 films micrographs reveal nanoblades and nanoblocks of Co3O4 densely distributed, suggesting high specific surface areas.
• The catalytic activity of the films was compared to data available in the literature and proved to be close to state-of-art results for the same reaction. However, given the difference of the experimental conditions, there were discrepancies.
• Routes for improvement of the catalytic activity will be proposed based on the results obtained and the literature review.