Tuning Extrinsic Stability of Rhodium Catalysts in Heterogeneous Hydroformylation

Understanding and mitigating metal leaching in heterogeneous catalysis are crucial for maintaining the stability and efficiency in liquid-phase hydroformylation. Here, we investigated the leaching mechanism of Rh using an ideal model catalyst, Rh 1 /ZnO(100), by combining density functional theory (DFT) calculations with experimental validation. Our findings reveal that Rh leaching is governed by two distinct molecular species, HRh(CO) n * and Rh(CO) n *, and exhibits pronounced temperature dependence. A volcano-shaped leaching trend was observed, peaking at 393 K, beyond which leaching decreased with increasing temperature. This behavior was also observed in other Rh-based catalysts, including Rh and Rh 2 P. Multiple other environmental factors, including CO and H 2 partial pressures and olefin concentration, modulated Rh leaching by altering the thermodynamic and kinetic stability of these species. Through such environmental modulation, Rh leaching was effectively controlled over a wide range, from 89.8% to a negligible level. These insights provide a molecular-level understanding of Rh leaching in hydroformylation and establish a foundation for improving catalyst durability without altering the intrinsic structure, thereby achieving extrinsic stability.