Synergistic RhFe Single-Atom Alloy and Nanoalloy Sites for Highly Efficient and Robust Heterogeneous Hydroformylation

Transforming homogeneous olefin hydroformylation into a robust heterogeneous process is hindered by Rh leaching and CO-induced suppression of H2 activation. Here, we report a dual-site RhFeSAA+NA/hydroxyapatite (HAP) catalyst featuring spatially differentiated RhFe single-atom alloy (SAA) and nanoalloy (NA) sites that overcomes the fundamental conflict between CO tolerance and reactivity. This cooperative architecture delivers >99% conversion and selectivity for styrenic and α-olefins (C6-C10) at 60 °C, and a TOF of 30,225.9 h-1 for propene hydroformylation at 110 °C with excellent antileaching ability. Mechanistic and operando studies reveal that the RhFe nanoalloy sites remain robust under CO-rich conditions to facilitate H2 dissociation, while neighboring single-atom alloy sites mediate the catalytic cycle. Hydrogen spillover from NA sites reconstructs the defect-rich Fe-HAP interface, creating a phosphate hydroxyl microenvironment that stabilizes interfacial CO and provides a local reservoir for carbonyl insertion. These findings demonstrate that dual-site catalysis coupled with interfacial engineering can bypass competitive adsorption in complex multisubstrate transformations.