Decarboxylation of Amino Acids to Bioamines over BaHPO4-Buffered Ru-RuO2 Catalysts

Waste protein-derived l-lysine was decarboxylated and hydrogenated to 1,5-pentanediamine (1,5-PDA) with great potential, which is an important feedstock for the production of the nylon PA56 monomer. In this study, a partially coated Ru-RuO2/BaHPO4 catalyst, with a controlled 26.5% surface Ru0 species, was developed from the RuO2/BaCO3 precursor using an encapsulation strategy with in situ generated 1,5-PDA as a gelling agent. As a result, l-lysine was decarboxylated and hydrogenated to 1,5-PDA via an intermediate of lysinal, affording a selectivity of 94.1%, space-time yield of 0.97 g·gcat–1·h–1, and TON of 374.6 at 170 °C. The Ru/RuO2-based catalyst demonstrated strong acid and over-reduction resistance, thereby providing a way to prepare robust catalysts for the synthesis of a wide range of amines from waste protein-derived amino acids.