In this work, the effect of pretreatment conditions (10% H2/Ar flow rate 25 mL/min and 400 °C, 3 h or 600 °C, 17 h) on the catalytic performance of 1 wt.% Pd/γ-Al2O3 has been evaluated for hydrogenation of 2-methyl-3-butyn-2-ol in continuous-flow mode. Two palladium catalysts have been tested under different conditions of pressure and temperature and characterized using various physicochemical techniques. The catalytic performance of red(400 °C)-Pd/γ-Al2O3 and red(600 °C)-Pd/γ-Al2O3 are affected by the coexistence of several related factors like the competition between PdH and PdCx formation during the reaction, structure sensitivity, hydrogen spillover to the alumina support and presence or absence of Pd–Al species. High-temperature reduction leads to formation of Pd–Al species in addition to pure Pd. The Pd–Al species which reveal unique electronic properties by decreasing the Pdδ− surface concentration via electron transfer from Pd to Al, leading to a weaker Pd–Alkyl bonding, additionally assisted by the hydrogen spillover, are the sites of improved semi-hydrogenation of 2-methyl-3-butyn-2-ol towards 2-methyl-3-buten-2-ol (97%)—an important intermediate for vitamin A synthesis.

Herein, the catalytic performance of palladium nanoparticles grafted on the polymeric TSNH2 (Tentagel-S-NH2) resin was investigated for continuous-flow liquid-phase hydrogenation of two industrially relevant chemicals: 2-methyl-3-butyn-2-ol and nitrocyclohexane. We investigated the effect of process parameters such as temperature and pressure on PdTSNH2 activity and selectivity. Depending on the reaction conditions, well-dispersed PdNPs with average size of about 2 nm have shown very high flexibility in terms selectivity toward the desired products: 2-methyl-3-buten-2-ol or 2-methyl-2-butanol in the case of 2-methyl-3-butyn-2-ol hydrogenation and cyclohexanone oxime or cyclohexylamine as the main product in the case of nitrocyclohexane conversion. The optimal reaction conditions for 2-methyl-3-buten-2-ol formation were estimated at 25 °C and 5 bar, and in the case of cyclohexanone oxime formation at 40 °C and 10 bar. We demonstrated the general trend in the catalytic performance of 2.2 wt% Pd grafted on Tentagel-S-NH2. Independently of the hydrogenated substrate, the increase in conversion leads to decreased selectivity to 2-methyl-3-buten-2-ol and cyclohexanone oxime at the expense of increasing the selectivity to 2-methyl-2-butanol or cyclohexylamine. Graphic abstract

A novel, eco‐friendly method for the activation of lignin by controlled oxidation was studied. The results obtained for six acidic imidazolium ionic liquids containing the hydrogen sulfate anion were compared. The key goal of this research was to increase the content of carbonyl groups in the lignin structure because these may play the main role in the transport of protons and electrons in active materials for electrochemical applications. By means of a variety of analytical techniques (FTIR, 13C CP/MAS NMR, and X‐ray photoelectron spectroscopy; selected reactions to determine the presence of carbonyl groups; SEM; zeta‐potential analysis; thermogravimetric analysis/differential thermogravimetric analysis; and porous structure analysis), it was determined that the product obtained after treatment with 3‐cyclohexyloxymethy‐1‐methylimidazolium hydrogen sulfate had favorable properties, in terms of the target application. Electrochemical tests proved that the obtained materials could be used as anodes in lithium batteries. The results show that the activation of lignin with ionic liquids can increase its capacity and maintain stability.