A novel Ru@GIS catalyst via interzeolite transformation for nylon 5X key monomer cadaverine synthesis

fL -lysine decarboxylation with zeolite-confined ruthenium (Ru) nanoparticle is a green and potential route to produce the new nylon 5X material key monomer cadaverine due to the low cost and overcapacity of L -lysine. Effect of zeolite frame -structure on decarboxylation performance is still an issue for effective synthesis of cadaverine. Through an inter-zeolite transformation strategy with Ru@FAU as crystal seed, Ru@GIS was synthesized and evaluated in L -lysine decarboxylation to clarify effect of channel size. FAU and GIS eutectic morphology (FAU/GIS) was also obtained by adjusting concentration of citric acid and crystallization time. Ru@GIS performed much better than Ru@FAU in L -lysine decarboxylation at 10 min with cadaverine productivity of 1120 g/L/h/mmol cat., which was triple than that in Ru@FAU (480.3 g/L/h/mmol cat.). Isothermal kinetics showed that conversion of L -lysine exhibited a typical characteristic of a first -order reaction with Ru@FAU and Ru@GIS. Abundant oxygen vacancies in Ru@GIS were supposed to play a vital role in stabilizing intermediate 2,6-diamino-1-hexanal, facilitating generation of target product cadaverine. The limited space in GIS can effectively inhibit side -reactions of cadaverine. The efficient performance of Ru@GIS provides a new route for efficient synthesis of nylon 5X key monomer cadaverine.