In-situ constructed Ru–RuOx heterointerface driving lysine decarboxylation via hydrogenation–decarbonylation tandem catalysis

Diamine synthesis from amino acids offers an economical and green route to high-value nylon monomers, yet developing highly efficient and stable catalysts remains challenging. This study developed a RuO x /TiO 2 catalyst that in-situ forms a Ru-RuO x heterointerface during the reaction, in which excellent 1,5-pentanediamine (PDA) yield (up to 69.8%) and productivity (63.5 h −1 ) for converting L-lysine achieved under 200 °C and 2 MPa H 2 , significantly outperforming other Ru-based catalysts supported on various carriers. Characterizations revealed that the strong RuO x -TiO 2 interaction suppresses partial reduction of RuO x , forming a Ru-RuO x interface—where Ru activates and dissociates H 2 while hydrogenating carboxyl groups to aldehydes, and RuO x catalyzes alcohol dehydrogenation, ultimately leading to PDA via aldehyde decarbonylation. Crucially, an optimal Ru-RuO x ratio is key to achieving both high yield and reaction rate. This work provides a novel strategy for developing catalysts for bio-based nylon monomers.