The present paper deals with the study on complete removal of CO in H-2-rich gas stream through CO-SMET over Ru-based catalysts supported on gamma-Al2O3 and CeO2 carriers. All the catalysts, loaded with 3% Ru, were prepared by a conventional impregnation method and their CO removal performance was determined at the powder level in a fixed bed micro reactor. The 3% Ru-gamma Al2O3 catalyst showed the best performance; consequently, it was deposited on microchannel metal plates reactor. With a catalyst load on the microchannel plates of 5 mg cm(-2) the performance was poor as complete CO conversion was not reached and also CO2 methanation was present. Increasing Ru load to 5%, the performance further worsened, the CO conversion decreased and higher amount of methane was produced. The catalytic activity on microchannel metal plates reactor was improved with the 3% Ru-gamma Al2O3 catalyst by doubling the its load on the surface (10 mg cm(-2)); the residual CO concentration decreased to about 100-150 ppmv at 310 degrees C, but a large amount of methane was formed also by the CO2 methanation, thus reducing catalyst selectivity. (C) 2010 Elsevier B.V. All rights reserved.