In-situ constructed Co@BOx/h-BN catalysts with Lewis acid sites and SMSI for efficient and recyclable olefin hydroformylation

Heterogeneous Co-based catalysts are increasingly sought-after in economical and sustainable hydroformylation process, however, their widespread application is hindered by low catalytic activity and severe metal leaching. Here, through the high-temperature pyrolysis-reduction of ZIF-67 and melamine diborate, we construct an in situ boron-doped, electron-deficient support and establish a Strong Metal-Support Interaction (SMSI). This strategy facilitates the adsorption of C=C bonds, thereby enhancing catalytic activity, while also inhibiting Co leaching to ensure catalyst stability. The resulting composite features Co nanoparticles, encapsulated by boron oxide (BO x ) overlayers and supported on porous hexagonal boron nitride ( h -BN). Furthermore, we demonstrate that the size of these Co nanoparticles can be finely tuned by regulating the synthetic conditions. In the hydroformylation of 1-octene, Co@BO x / h -BN- 900- 4(1:1) exhibits outstanding catalytic performance with 99.9% 1-octene conversion and 95.0% aldehyde selectivity under optimum conditions, ascribing to electron-deficient boron and robust SMSI. Boron acts as Lewis acid site favoring the adsorption of C=C bond, which can be proved by the test of adding Lewis base into the hydroformylation of 1-octene, there is strong inhibition on the reaction and thus dramatically lowering aldehyde selectivity even though a small quantity of triethylamine. SMSI induced by encapsulation of BO x overlayers not only suppresses agglomeration and leaching of Co nanoparticles but also generates electron-deficient Co δ+ species facilitating CO adsorption, leading to the catalyst’s high activity and selectivity, as well as high stability in a long-lasting test. This work provides meaningful insights into transition metal catalysts optimized by electron-deficient support and SMSI for olefin hydroformylation.