Search

Binary Ni–Cu heterogeneous catalysts are known to demonstrate excellent activity in conventional hydrogenation of phenolic compounds, and Cu addition facilitates hydrodeoxygenation (HDO). In this study, we aimed to show the effect of Cu on the specific catalytic activity and selectivity of Ni–Cu catalysts in transfer hydrogenation, in which 2-PrOH was used as a solvent and an H donor. Catalytic transformations of anisole were studied in sub- and supercritical alcohol at 150 and 250 °C. The catalysts were prepared using an environmentally friendly supercritical antisolvent coprecipitation method, which makes it possible to obtain well-dispersed particles (less than 7 nm) at high metal loading (up to 50 wt.%). When copper is added, deactivation of the catalyst in transformations of anisole, including HDO, is observed. The experimental data and the appropriate kinetic analysis demonstrate that there is a decrease in the rate of anisole conversion accompanied by an increase in the concentration of acetone formed during the dehydrogenation of 2-PrOH. [ABSTRACT FROM AUTHOR]

• Ni/Al 2 O 3 and Ni-Co/Al 2 O 3 showed high activity in transfer hydrogenation of phenolics. • Ni/Al 2 O 3 primarily promotes hydrodearomatization of phenolic compounds. • The addition of Co to Ni facilitates hydrodeoxygenation of anisole and guaicol. The study investigated the transfer hydrogenation of guaiacol, anisole, phenol, and positional isomers of dimethoxybenezene using 2-PrOH as the H-donor over Ni, Co, and Ni-Co catalysts. The catalysts, which contained 5 wt% metal, were prepared by the deposition-precipitation method. The results showed that the catalysts had developed a pore structure and fine metal particles. The Ni and Ni-Co catalysts demonstrated exceptional activity in the transfer hydrogenation of phenolic compounds with a substrate to metal molar ratio of 100 to 1. Furthermore, the addition of Co to Ni significantly impacted the selectivity of transfer hydrogenation promoting hydrodeoxygenation of anisole and guaiacol. [Display omitted] [ABSTRACT FROM AUTHOR]

Transfer hydrogenation of anisole in 2-PrOH has been studied as a model reaction for lignocellulose processing. The reaction was studied over high-loaded Ni-based catalysts synthesized via supercritical antisolvent precipitation of a Ni precursor and sols of four oxides: Al 2 O 3 , SiO 2 , TiO 2 , and ZrO 2. It was demonstrated that the oxide support significantly affects the structure of the catalysts, their activity, and selectivity. The best performance in the transfer hydrodeoxygenation of anisole was shown by Ni supported on alumina at 250 °C, which was explained by the highest dispersion of Ni0 particles in this catalyst and by the highest concentration of acid centers. [Display omitted] • Well-dispersed high-loaded Ni catalysts were synthesized by SAS method. • Obtained catalysts show excellent activity in transfer hydrogenation of anisole. • Acid sites and the smaller Ni particles facilitate hydrodeoxygenation of anisole. [ABSTRACT FROM AUTHOR]