Heterogeneous hydroformylation of alkenes through formic acid path

Hydroformylation is an important industrial route to aldehyde, yet it typically relies on pressurized syngas and homogeneous catalysts that complicate separation and recycling. Formic acid (FA) is an attractive liquid surrogate for CO/H₂. However, coupling FA decomposition chemistry with hydroformylation in a single, recyclable solid-catalyst platform remains challenging because multiple competing decomposition pathways must be controlled. Here, we show that a bifunctional Ru/ZSM-5 model catalyst couples FA activation with the hydroformylation of 1-hexene under solvent- and ligand-free conditions, and we benchmark its catalytic performance using a Ru-normalized production rate. Propionic anhydride acts as a promoter that markedly increases aldehyde productivity (up to ∼11-fold under the reported conditions) without significantly altering linear/branched selectivity. Isotopic labeling with H13COOH confirms that the aldehyde carbonyl carbon originates exclusively from FA, providing direct evidence for FA-to-aldehyde carbon transfer in a heterogeneous reaction setting. Temperature-programmed FA decomposition and in situ infrared spectroscopy support a bifunctional picture in which ZSM-5 favors CO-forming dehydration while Ru promotes H₂-forming dehydrogenation, enabling the in situ generation of syngas equivalents compatible with aldehyde formation.