Fischer-Tropsch Synthesis on ALD-Synthesized Catalysts

Development of a cost-effective distributed/mobile gas-to-liquids technology for producing synthetic crude oil that can be moved from well-to-well as gas depletes, is an attractive alternative to flaring.  Cobalt catalysts were prepared on porous Al₂O₃ supports by atomic layer deposition (ALD).  Some of these catalysts had CO reaction rates per g of Co in Fischer-Tropsch synthesis (FTS) that were three times those reported for Co catalysts prepared by incipient wetness. The FTS reacts CO and H₂ to form hydrocarbon liquids that can used as synthetic fuels. The rate of FTS depended on the number of ALD cycles, and catalysts prepared with one cycle had activities equivalent to incipient wetness Co catalysts; the highest reaction rate per g of catalyst was obtained for catalysts prepared using four ALD cycles. Cobalt catalysts prepared by ALD retained adsorbed ligands that appeared to be stable for at least eight months at room temperature.