Preferential oxidation of CO in a microreactor with a single channel

A silicon microreactor was tested for the preferential oxidation of CO to reduce CO in reformate. Thin-film Pt/Al₂O₃ catalyst was deposited on walls of microreactors with two methods and its activity was evaluated after different pretreatments. The adhesion of the catalyst to the microchannel walls was excellent and fairly uniform. The conversion of CO increased with increasing temperature; however, the activity of the catalyst in all microreactors was low. The activity of catalysts in all microreactors was higher than during the first cycle of testing. Repeated catalyst exposure to higher temperature was an important factor in enhancing the catalyst activity. The microreactors with a highly active catalyst showed a characteristic behavior. The conversion of CO increased with increasing temperature fairly linearly and there was a characteristic temperature at which a steep increase in conversion reaching almost 100% was observed.