Ultrasound-excited hydrogen radical from NiFe layered double hydroxide for preparation of ultrafine supported Ru nanocatalysts in hydrogen storage of N-ethylcarbazole

• Published in: Ultrasonics sonochemistry 2021-12, Vol.81, p.105840-105840, Article 105840
• Main Authors: Liu, Xiaoran, Shi, Jiaming, Bai, Xuefeng, Wu, Wei
• Format: Article
• Language: English
• Subjects: Hydrogen storage; N-ethylcarbazole; NiFe layered double hydroxide; Short Communication; Ultrafine Ru nanoparticles; Ultrasound-excited
• ISSN: 1350-4177; 1873-2828
• DOI: 10.1016/j.ultsonch.2021.105840

[Display omitted] •Highly active Ru/NiFe-LDH is prepared by ultrasound-assisted reduction method.•–OH on the NiFe-LDH is excited into H radicals (H) as reductant via ultrasound.•Ultrafine Ru NPs show excellent catalytic performance for NEC hydrogenation.•The complexation of Ru with O-contained groups on NiFe-LDH improves its stability. Highly active Ru nanoparticles (Ru NPs) supported on NiFe layered double hydroxide (Ru/NiFe-LDH) are prepared easily using ultrasound-assisted reduction method without chemical reductants and stabilizers. The plentiful hydroxyls on NiFe-LDH are excited into hydrogen radicals (H) under the action of ultrasound for reducing Ru3+ to Ru0. Ru NPs with an average particle size of 1.26 nm highly disperse on the mesopore-like surface of NiFe-LDH, which improve the catalytic performance for N-ethylcarbazole (NEC) hydrogenation. The experimental results show that 5Ru/NiFe-LDH-300–60 exhibits the best catalytic performance with 100% conversion of NEC, 98.88% yield of dodecahydro-N-ethylcarbazole (12H-NEC) and 5.77 wt% mass hydrogen storage capacity under the reaction conditions of 110 ℃, 6 MPa and mRu:mNEC = 0.15 wt% for 80 min. The kinetics study shows that the apparent activation energy is only 25.15 kJ/mol, which is the lowest in the reported literatures. Ru complexes with O-contained groups on NiFe-LDH, improving the catalytic stability in NEC hydrogenation.