Atomic Layer Deposition of Iron Sulfide and Its Application as a Catalyst in the Hydrogenation of Azobenzenes

The atomic layer deposition (ALD) of iron sulfide (FeS x ) is reported for the first time. The deposition process employs bis( N , N′ ‐di‐tert‐butylacetamidinato)iron(II) and H 2 S as the reactants and produces fairly pure, smooth, and well‐crystallized FeS x thin films following an ideal self‐limiting ALD growth behavior. The FeS x films can be uniformly and conformally deposited into deep narrow trenches with aspect ratios as high as 10:1, which highlights the broad applicability of this ALD process for engineering the surface of complex 3D nanostructures in general. Highly uniform nanoscale FeS x coatings on porous γ‐Al 2 O 3 powder were also prepared. This compound shows excellent catalytic activity and selectivity in the hydrogenation of azo compounds under mild reaction conditions, demonstrating the promise of ALD FeS x as a catalyst for organic reactions.