Copper-Organic Framework-Derived Porous Nanorods for Chemoselective Hydrogenation of Quinoline Compounds at an Aqueous/Oil Interface

Abstract

In this work, a Cu-BTC material was first synthesized by a hydrothermal rota-crystallization method using cupric nitrate and benzene-1,3,5-tricarboxylate (BTC) as raw materials. Compared with a conventional hydrothermal method, this route greatly shortened the synthesis time of Cu-BTC to only 2 h. Cu-BTC was then treated under a N 2 atmosphere at different times and temperatures to obtain the derivative Cu/C-x-t with exceptional hydrophobicity (WCA of 146°), where x represents the pyrolysis temperature and t was the pyrolysis time. The size effect of Cu NPs on carbon played a critical role in promoting the reaction efficiency. The thus-synthesized Cu/C-x-t material acted as an excellent catalyst for the quinoline hydrogenation in an aqueous medium. It was found that the catalytic reactivity of Cu/C attained the highest value at 600 °C for 2 h; the conversion of quinoline reached 95.2 mol % and the selectivity of 1,2,3,4-tetrahydroquinoline (THQ) was >99% under mild aqueous reaction conditions. This could be attributed to the hydrophobic surface structure of Cu/C-600 and the interaction between Cu nanoparticles and the surface C matrix, to form a special aqueous/oil microenvironment on the surface of the catalyst and to accelerate the interfacial reactions.

Selective Hydrogenation of N-Heterocyclic Carboxylate over Nitrogen-Doped Porous Carbon-Supported Nano-Ni

“…It can be clearly seen that when THF was added, the contact angle was close to 0°, indicating that the catalyst was lyophilic, so THF can well wet the catalyst with good wettability. Therefore, the good lipophilicity of the catalyst was beneficial to the dispersion of the catalyst in the solvent THF and the full contact with the substrate, thus promoting the catalytic reaction. − …”

Nanocatalysts Derived from Copper Phyllosilicate for Selective Hydrogenation of Quinoline

“…When methyl or amino groups appeared on the ring (entries 1–3), the conversion reached >98.0% and the selectivity was >96% . These results are due to the fact that the electron-donating groups stabilize the positive charge and favor the selective hydrogenation of the pyridine ring, thus leading to high activity and selectivity . When these groups were substituted with the electron-absorbing chlorine or nitro group (entries 4–6), the activity was relatively low.…”

“…These results are due to the fact that the electron-donating groups stabilize the positive charge and favor the selective hydrogenation of the pyridine ring, thus leading to high activity and selectivity. 61 When these groups were substituted with the electron-absorbing chlorine or nitro group (entries 4−6), the activity was relatively low. The conversion of 5-nitroquinoline was only 65.1%, and 2chloroquine had a conversion of 85.1% under more stringent reaction conditions (120 °C and 6 h); these results are because the fracture of the ring due to the electron-absorbing nitro and chlorine groups is unfavorable for the selective hydrogenation of the pyridine ring.…”

N-doped semi-graphitic C loaded with metallic Co: synthesis parameters and catalytic selective reduction of p-nitrophenol

“…A great number of studies showed that the carbon defects could produce unpaired p electrons, thereby promoting electron transfer and the adsorption of certain substrates, which may be one of the reasons why this material presented good catalytic performance in a series of catalysts. 37 Thermogram curves of Co/CN-x prepared at different pyrolysis temperatures are given in Fig. 6(b).…”