Co-MCM-41 and Ni-MCM-41 derived catalysts are good catalysts for the synthesis of SWNT. Co-MCM-41 is the first catalysts tested for this reaction, for which the physical and chemical properties were already well characterized. The conversion of CO at different temperatures and with different pretreatments was studied. Co incorporated MCM-41 had a higher stability than the impregnated catalyst, which can be explained by the anchoring effect of small metallic Co clusters to the unreduced Co in the MCM-41 framework. The catalytic reaction using Ni-MCM-41 showed much higher reactivity than Co-MCM-41 under the same conditions. The reaction order of CO of incorporated and impregnated Co and Ni-MCM-41 showed totally different results: the incorporated one preparation was positive and the impregnated one was negative order. Metal particles formed from Co-MCM-41 and Ni-MCM-41 were decorated with silica or occluded in the silica matrix weakening CO chemisorption. This is an abstract of a paper presented at the AIChE Annual Meeting and Fall Showcase (Cincinnati, OH 1/04/2005).