Stabilizing Optimal Crystalline Facet of Cobalt Catalysts for Fischer-Tropsch Synthesis.

Developing efficient catalysts with a stable optimal crystalline facet is highly promising yet challenging for the Fischer-Tropsch synthesis (FTS). Here, we demonstrate a coating strategy to fabricate a stable optimal cobalt-facet catalyst. The catalyst (Co@C-SiO2) is composed of a single crystalline core, a wrapped carbon layer, and an amorphous silica shell. The moderate metal-support interaction endowed by carbon, combining the confined effect of the silica shell, protects and maintains the single-crystal structure and optimal crystalline facet of the core, that is, Co(10-11). Due to the unique core-shell nanostructure and optimal cobalt facets, our Co@C-SiO2 catalyst shows a remarkable low methane selectivity (5.3%), high activity (TOF = 4.0 × 10-2 s-1), C5+ selectivity (88.9%), and more importantly, excellent stability (TOS = 168 h) in FTS.