Efficient Fe‐Based Catalysts Prepared by Atomic Layer Deposition for CO ₂ Hydrogenation to Higher Hydrocarbons

In this work, atomic layer deposition (ALD) of Fe is applied for the first time to prepare YZrO x ‐supported catalysts for CO 2 Fischer–Tropsch synthesis (CO 2 ‐FTS). The ALD catalysts promoted via physical mixing with K 2 CO 3 clearly outperformed a catalyst of the same K‐Fe loading but prepared via incipient wetness impregnation (IWI) by achieving higher CO 2 conversion and lower CH 4 selectivity. The best K‐promoted ALD catalyst achieved similar C 2+ ‐hydrocarbon and C 2 ‐C 4 olefin yield and suppression of CH 4 formation as state‐of‐the‐art bulk Fe‐based catalysts, despite its significantly lower Fe content. Spatially resolved characterization of spent catalysts revealed that the superior performance of the K‐promoted ALD catalysts is linked to a higher Fe 5 C 2 content and an improved spatial distribution of Fe 5 C 2 along the catalyst bed. The enhanced formation/stabilization and distribution of Fe 5 C 2 in the ALD catalysts may be related to differences in Fe species morphology, which may interact more significantly with K 2 CO 3 . Additionally, operando DRIFTS measurements revealed different intermediates on the surface of IWI and ALD catalysts possibly involved in CH 4 and higher hydrocarbon formation. We put forward that ALD is an advantageous method for preparing efficient supported Fe‐based catalysts for CO 2 ‐FTS, which offers a new opportunity to explore for selectivity tuning and activity enhancement.