620-14-4Relevant articles and documents
Alkylation of toluene with ethanol to para-ethyltoluene over MFI zeolites: Comparative study and kinetic modeling
Ogunbadejo, Babatunde A.,Osman, Mogahid S.,Arudra, Palani,Aitani, Abdullah M.,Al-Khattaf, Sulaiman S.
, p. 109 - 117 (2015)
The production of para-ethyltoluene (p-ET) from the alkylation of toluene with ethanol was investigated over three MFI zeolites with varying SiO2/Al2O3 ratio (80, 280, and 2000). The ethylation reaction was conducted in a batch fluidized-bed reactor at a temperature range of 300-400 °C, reaction times of 5-20 s and molar feed ratio of toluene to ethanol at 1:1. Toluene conversion increased with temperature over all the MFI zeolites except for MFI-80, which showed a maximum conversion of 29% at 300°C. The product distribution exhibited ethyltoluenes as major product with a maximum yield of 26% over MFI-80. At 400°C, constant toluene conversion of 14% and 100% ethanol conversion, para-selectivity to p-ET was 100% over MFI-2000 compared with 27% and 48% over MFI-80 and MFI-280, respectively. The high para-selectivity over MFI-2000 is attributed to the combined effects of higher SiO2/Al2O3 ratio, very weak acid sites and larger crystal size (longer diffusion length). The experimental data were analyzed for each MFI zeolite and suitable reaction mechanism for toluene ethylation was proposed based on the Langmuir-Hinshelwood model. The activation energy for the formation of p-ET over MFI-280 and MFI-2000 is 30 kJ/mol and 65 kJ/mol, while the heat of adsorption of ethanol is 19 kJ/mol and 29 kJ/mol, respectively.
Controlling the Lewis Acidity and Polymerizing Effectively Prevent Frustrated Lewis Pairs from Deactivation in the Hydrogenation of Terminal Alkynes
Geng, Jiao,Hu, Xingbang,Liu, Qiang,Wu, Youting,Yang, Liu,Yao, Chenfei
, p. 3685 - 3690 (2021/05/31)
Two strategies were reported to prevent the deactivation of Frustrated Lewis pairs (FLPs) in the hydrogenation of terminal alkynes: reducing the Lewis acidity and polymerizing the Lewis acid. A polymeric Lewis acid (P-BPh3) with high stability was designed and synthesized. Excellent conversion (up to 99%) and selectivity can be achieved in the hydrogenation of terminal alkynes catalyzed by P-BPh3. This catalytic system works quite well for different substrates. In addition, the P-BPh3 can be easily recycled.
Highly selective hydrogenation of aromatic ketones to alcohols in water: effect of PdO and ZrO2
Alsalahi, W.,Trzeciak, A. M.,Tylus, W.
, p. 10386 - 10393 (2021/08/09)
Pd/ZrO2and PdO/ZrO2composites, containing Pd or PdO nanoparticles, were prepared using an original one-step methodology. These nanocomposites catalyze the hydrogenation of acetophenone (AP) at 1 bar and 10 bar of H2in an aqueous solution. Compared to unsupported Pd or PdO nanoparticles, a remarkable increase in their activity was achieved as a result of interaction with zirconia. An unsupported PdO hydrogenated AP mainly to ethylbenzene (EB), while excellent regioselectivity towards 1-phenylethanol (PE) was obtained with PdO/ZrO2and it was preserved during recycling. Similarly, regioselectivity to PE was higher with Pd/ZrO2compared to unsupported Pd NPs. PdO and zirconia resulted in high selectivity to alcohols in the hydrogenation of substituted acetophenones.
Chemoselective Hydrogenation of Olefins Using a Nanostructured Nickel Catalyst
Klarner, Mara,Bieger, Sandra,Drechsler, Markus,Kempe, Rhett
supporting information, p. 2157 - 2161 (2021/05/21)
The selective hydrogenation of functionalized olefins is of great importance in the chemical and pharmaceutical industry. Here, we report on a nanostructured nickel catalyst that enables the selective hydrogenation of purely aliphatic and functionalized olefins under mild conditions. The earth-abundant metal catalyst allows the selective hydrogenation of sterically protected olefins and further tolerates functional groups such as carbonyls, esters, ethers and nitriles. The characterization of our catalyst revealed the formation of surface oxidized metallic nickel nanoparticles stabilized by a N-doped carbon layer on the active carbon support.
