Selective Formation of Hägg Iron Carbide with g‐C 3 N 4 as a Sacrificial Support for Highly Active Fischer–Tropsch Synthesis

The Fischer–Tropsch synthesis (FTS) is a feasible pathway to chemicals and fuels from underutilized resources like coal, natural gas, biomass, and shale gas, instead of the current petroleum‐based production. Owing to its high activity and low price, the iron‐based catalysts are widely used in FTS, yet catalysts with higher activity and better selectivity should be developed for widespread applications. Herein, we report a unique strategy to synthesize an efficient iron catalyst for FTS by applying a graphitic carbon nitride (g‐C 3 N 4 ) as a sacrificial support. The iron catalyst on g‐C 3 N 4 is effectively reduced to a state that is rapidly and selectively converted to highly crystalline and pure Hägg carbide (χ‐Fe 5 C 2 ) phase during the FTS reaction. The obtained catalyst exhibits outstanding CO conversion, and high selectivity for C 5+ products, outperforming most of the recently reported carbon‐based iron catalysts.