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

Abstract

Graphical abstract

Elaborately tailored NiCo2O4 for highly efficient overall water splitting and urea electrolysis

“…S15d and e †), the Ru 3p and Ru 3d peaks are shifted to lower bonding energy, indicating that the oxidative Ru species are mainly reduced into Ru 0 throughout the HER process. 57 Consequently, it is believed that metallic Ru is the primarily active sites for HER. (The surface and in situ embedded nanoneedle arrays Ru-NiCo 2 O 4 with an appropriate amount and highly-dispersed Ru nanoparticles can serve as the primary HER active site.)…”

Ultrasonic-assisted preparation of ultrafine Pd nanocatalysts loaded on Cl−-intercalated MgAl layered double hydroxides for the catalytic dehydrogenation of dodecahydro-N-ethylcarbazole

“…The collapse of cavitation bubbles will produce high temperature, high pressure and so on of special physical and chemical changes, which provides favorable conditions for the rapid synthesis of nanomaterials with uniform particle size distributions. Liu [43] prepared RuNPs loaded on NiFe-LDHs by ultrasonic-assisted reduction, showing excellent catalytic activity in NEC hydrogenation. The surface hydroxyl groups of the carrier were excited into •H under ultrasound to reduce Ru 3+ .…”

Ultrasound-assisted green synthesis of Ru supported on LDH-CNT composites as an efficient catalyst for N-ethylcarbazole hydrogenation

“…Previous studies have found that when using the ultrasound-assisted reduction method to prepare Ru-based catalysts supported on LDH, if the ultrasonic power is too low or the ultrasonic time is too short, the generated energy is not enough to excite the —OH groups on the surface of LDH to produce enough •H, resulting in incomplete reduction of Ru 3+ . However, too high ultrasonic power and too long ultrasonic time can easily cause Ru NPs to agglomerate, leading to a decrease in the number of exposed active sites [36] . Therefore, the selection of ultrasonic preparation conditions is necessary.…”

“…This extraordinary high-energy environment provides a special platform for the growth of novel nanostructures [33] , [34] . Our previous study found that under ultrasonic conditions, the hydroxyl groups on the surface of LDH were excited to generate highly reducing hydrogen radicals (•H), which successfully reduced the supported noble metal cations [35] , [36] . Compared with the traditional chemical reduction method, this method does not require the addition of chemical reducing agents and stabilizers, and the obtained metal nanoparticles are smaller and highly dispersed.…”