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

Tuning the Interaction between Pd and MgAl2O4 To Enhance the Dehydrogenation Activity and Selectivity of Dodecahydro-N-ethylcarbazole

“…According to the above analysis, the size of Pd particles distributed on the surface of the Pd/MgAl 2 O 4 –973 K catalyst was the smallest. The dehydrogenation reaction was a structure-sensitive reaction, and the size of active metal particles had a strong effect on the dehydrogenation reaction. , Pd/MgAl 2 O 4 –973 K had the medium acidic site density and the strongest acidic site intensity for the same metal loading, which may make the Pd particles in the catalyst more dispersed and the synergy effect between metal sites and acid sites stronger, thus promoting the dehydrogenation reaction. , In addition, the Pd/MgAl 2 O 4 –973 K catalyst had the highest content of highly reactive Pd 0 , which was consistent with the phenomenon reported in previous reports. , However, some reports had revealed that the catalytic activity of Pd-based catalysts for dehydrogenation reactions could be improved by partially positively charged Pd because this state of Pd was more conducive to the adsorption and desorption of hydrogen storage carriers and dehydrogenation products. − At the same time, the easy desorption of dehydrogenation products made their residence time at active sites shorter and less likely to undergo further dealkylation reactions due to too long contact time with the active sites, while providing more active sites for the dehydrogenation reaction to promote the dehydrogenation reaction. In addition, Bai and co-workers prepared a catalyst (S15-Si-O) 2 Pd in which Pd was completely in the oxidation state and almost did not catalyze the occurrence of 12H-NEC dehydrogenation .…”

“…32,35 In addition, the Pd/MgAl 2 O 4 −973 K catalyst had the highest content of highly reactive Pd 0 , which was consistent with the phenomenon reported in previous reports. 19,41 However, some reports had revealed that the catalytic activity of Pd-based catalysts for dehydrogenation reactions could be improved by partially positively charged Pd because this state of Pd was more conducive to the adsorption and desorption of hydrogen storage carriers and dehydrogenation products. 42−44 At the same time, the easy desorption of dehydrogenation products made their residence time at active sites shorter and less likely to undergo further dealkylation reactions due to too long contact time with the active sites, while providing more active sites for the dehydrogenation reaction to promote the dehydrogenation reaction.…”

Intrinsic Kinetics of Dibenzyltoluene Hydrogenation over a Supported Ni Catalyst for Green Hydrogen Storage

“…Typical LOHCs can be divided into aromatic compounds and heterocyclic compounds (mainly nitrogen-containing heterocycles), the former mainly includes toluene/methylcyclohexane, − dibenzyltoluene (DBT)/perhydro-dibenzyltoluene (18H-DBT), − benzyltoluene (BT)/perhydro-benzyltoluene (12H-BT), ,− while the latter primarily involves N-ethylcarbazole (NEC)/dodecahydro-N-ethylcarbazole (12H-NEC), − N-propylcarbazole (NPC)/dodecahydro-N-propylcarbazole (12H-NPC), , methylindole (MID)/octahydro-methylindole (8H-MID), − et al Among them, the DBT/18H-DBT system has excellent technical availability with a high hydrogen storage density of 0.91 kg·L –1 , good physical properties and thermal stability (see Table S1 (SI)). ,,, Apart from this, good cyclic performance − and high-purity hydrogen release , have been experimentally verified in DBT/18H-DBT system, and it was first commercialized by Hydrogenious LOHC Technologies (Germany) and the containerized dehydrogenation units are being developed to supply hydrogen to hydrogen filling stations in Europe . However, high viscosity and high dehydrogenation reaction temperature are not negligible issues for this system in practical applications.…”

Ultrasound-assisted synthesis of graphene@MXene hybrid: A novel and promising material for electrochemical sensing

“…In recent years, ultrasound-assisted synthesis method has been considered to be a kind of simple, green, low-cost and promising technology for preparing various functional nanomaterials. During the sonication process, plenty of cavitation bubbles were generated and then collapsed in the liquid environment, the collapsed cavitation bubbles can result in instantaneous high temperature and high pressure, which make it possible to actuate certain physical/chemical reaction and obtain the nanomaterials with different morphology and composition [29] . For example, Ru nanoparticles decorated NiFe layered double hydroxide with excellent hydrogenation catalytic activity [30] , cyclodextrin metal–organic framework with superior antibacterial activity [31] , platinum-cobalt modified carbon-encapsulated polyaniline with substantial oxygen reduction reaction activity [32] and so on have been successfully obtained through ultrasound-assisted synthesis methods.…”