Precursor Nuclearity and Ligand Effects in Atomically‐Dispersed Heterogeneous Iron Catalysts for Alkyne Semi‐Hydrogenation

Nanostructuring earth-abundant metals as single atoms or clusters of controlled size on suitable carriers opens new routes to develop high-performing heterogeneous catalysts, but resolving speciation trends remains challenging. Here, we investigate the potential low-nuclearity iron catalysts in continuous liquid-phase semi-hydrogenation various alkynes. The activity depends multiple factors, including nuclearity and ligand sphere metal precursor their evolution upon interaction with mesoporous graphitic carbon nitride scaffold. Density functional theory predicts favorable adsorption precursors scaffold without altering preserving some ligands. Contrary previous observations for palladium exhibit higher than larger clusters. Atomistic simulations suggest a central role residual carbonyl species permitting low-energy paths over these isolated centers.