Fischer-Tropsch (FT) synthesis was carried out using 3D-printed stainless steel (SS) microreactors, containing channels of dimensions 500 mu m x 500 mu m x 2.7 cm, to study the effect of Fe, Ru, and Ni on Co-MCM-41 catalyst. The mono and bimetallic cobalt-based catalysts: 15 % Co-MCM-41, 10 %Co5% Ru MCM-41, 10 %Co 5%Ni MCM41, and 10 %Co 5%Fe MCM-41 were synthesized using one-pot hydrothermal method and characterized by SEMEDX, TEM, TPR, FTIR, XPS, and low and wide angle XRD techniques. All the catalysts exhibited high surface area without the loss of ordered mesoporous structure as confirmed by large BET surface areas (400-1000 m(2)/g) and low angle XRD data. The metal nanoparticles were in the range of 35-50 nm and well dispersed in a hexagonal matrix of MCM-41. TPR data indicate that all other metal oxides except that of cobalt can be reduced with H-2 below 600 degrees C. Cobalt is present most likely as cobalt silicates that can only be reduced with H-2 at a temperature over 650 degrees C. The microchannels of SS reactor were uniformly coated by dip coating a slurry of the catalyst with polyvinyl alcohol (PVA). The catalytic performance for FT synthesis was carried out in the SS microreactor at atmospheric pressure in the temperature range of 180-300 degrees C with H-2/CO molar ratio of 3. Incorporation of the second metal in the Co-MCM-41 framework and the operating temperature had a significant effect on CO conversion and selectivity towards C1-C4 alkanes in FT synthesis. While the highest CO conversion of 74 % was obtained for CoFe-MCM-41 at 240 degrees C, the highest selectivity towards butane (11 %) and propane (39 %) was observed for CoRu-MCM-41 at 240 degrees C and CoFe-MCM-41 at 210 degrees C, respectively. The rate of deactivation of the catalysts-followed the order: CoRu-MCM-41 > CoNi-MCM-41 > Co-MCM-41 > CoFe-MCM-41, indicating that CoFe-MCM-41 is the most suitable catalyst for F-T synthesis in terms of long term stability.