Amorphous Silica/NaNbO Crystal Heterophase Junction-Supported Ru Catalyst with Optimized Surface and Electron Structure for Highly Efficient Hydrogenation of α-Pinene.

The development of hydrogenation catalysts with high performance and stability could decrease the byproducts and simplify the follow-up process in the industrial process. Optimizing supported catalysts through support improvement is a feasible approach to balance effectiveness and cost. In view of this, cubic perovskite NaNbO was modified with organosiloxane to form a heterophase junction support consisting of amorphous silica and NaNbO crystal. On the basis of this, the supported Ru catalyst displayed superior performance for α-pinene hydrogenation with almost complete conversion, -pinane selectivity, and good stability. The relationship between the structure and performance of the catalyst was systematically investigated by comprehensive experiments and multiple characterization technologies. Due to the formation of the heterophase junction, the surface hydrophobicity, specific surface area, and electron properties of the catalyst were optimized, leading to the good dispersity of the catalyst in the hydrogenation mixture and excellent adsorption and charge transfer ability, which should account for the unique performance of the catalyst, as confirmed by a series of experiments, characterizations, and DFT calculations. This work proposes an effective approach to optimize the surface structure and electronic properties of the catalysts through constructing crystallized and amorphous heterophase junction support, which is theoretically significant for the design and development of cost-effective heterogeneous hydrogenation catalysts.