Effect of titania support on Fischer-Tropsch synthesis using cobalt, iron, and ruthenium catalysts in silicon-microchannel microreactor

Abstract Syngas conversion into hydrocarbons using Fischer Tropsch (F-T) Synthesis was carried out to investigate the effect of TiO2 support on catalytic performance using 12% by weight of metal -12Co-TiO2, 12Fe-TiO2 and 12Ru-TiO2 in silicon (Si) microchannel microreactor (50 μm wide x100 μm deep) at different reaction temperatures and 1 atm. A modified closed channel infiltration (mCCI) method was used for successful uniform coating of the sol-gel catalyst layer in the micro-channels of Si-microrecators. Temperature Program Reduction profiles with H2 showed interaction of TiO2 with each metal to be significantly different; TPR of Fe-TiO2 and Co-TiO2 indicated a significant strong metal (Co and Fe) support interaction (SMSI), while that of Ru-TiO2 suggested a weaker metal-support interaction. The XRD studies of the catalysts suggest that unlike Fe- and Co-TiO2, Ru-TiO2 consists of mixed anatase and rutile phases of TiO2. The absence of rutile phase in Co-TiO2 and Fe-TiO2 had a profound effect on F-T activity in the range of 150 °C to 300 °C for CO conversion and hydrocarbon selectivity at 1 atm and decreased the stability of these two catalysts. The overall stability and reactivity was in the order: 12%Ru-TiO2>> 12%Fe-TiO2 > 12%Co-TiO2. These results are distinctly different from our previous studies with silica sol-gel in microreactor where a reverse trend was observed.