Self-Anticoking of a Cobalt Surface by Subsurface Oxygen in the Fischer-Tropsch Synthesis

Understanding the fundamental processes taking place on Co surfaces during the Fischer-Tropsch (FT) synthesis is of great interest and importance. We herein report a self-anticoking mechanism of a cobalt surface by subsurface oxygen. The active carbidic carbon species for FT synthesis tends to transform into the inactive graphitic carbon species on clean Co(0001) and poisons the Co surface. Subsurface atomic oxygen on Co(0001) can stabilize the active carbidic carbon species and quench the transformation process. These results reveal, to the best of our knowledge, for the first time the reactivity of various surface species on Co surfaces that dynamically maintain a delicate balance to enhance the long-term stability of Co catalysts during FT synthesis.