High-loaded Ni-based catalysts obtained via supercritical antisolvent coprecipitation in transfer hydrogenation of anisole: Influence of the support

Reactivation of Ni‐TiO2 catalysts in hydrogen flow and in supercritical 2‐propanol—Comparative study by electron spin resonance in situ

“…The SAS technique allows to obtain highly loaded systems with rather narrow size distribution. 20 TiO 2 itself tends to recrystallize at high temperatures, as rutile and anatase reflexes can be detected by XRD analysis of calcined samples (Figure S3, SI). To obtain NiO nanoparticles, the third step, which is the reduction in the temperature range of 300-700 C in a hydrogen atmosphere, is mandatory.…”

“…40 Indeed, the study of the results of the kinetic experiments of anisole hydrogenation in the 2-PrOH medium catalyzed by Ni-TiO 2 shows a small discrepancy in the reaction rate of the anisole conversion in the initial stages of the process (see Figure 4), which has been described elsewhere. 20 The reduction of anisole to methoxycyclohexane under the reaction conditions (T = 250 C, P = 71-78 bar) can be simulated by first order kinetics. As can be seen from Figure 4, during the first 20-40 min of the reaction, the reaction rate increases, which corresponds to the increase in the slope of the kinetic curve.…”

“…The synthesis technique is described in detail in the work. 20 The kinetics studies were carried out in a batch reactor (AISI 316L, 285 mL, Parker Autoclave Engineers, USA) previously purged with Ar and filled with the catalyst suspension and 30 mL of 2-PrOH. The reactor configuration allows experiments to be carried out at temperatures up to 450 C and pressures up to 270 bar.…”

“…The liquid samples were analyzed using a Shimadzu GCMS-QP2010 SE chromatomass spectrometer equipped with an autosampler. The details of the kinetics studies can be found in the Supporting Information (SI) S1 and are described in the work of Philippov et al 20 Transmission electron microscope (TEM) studies were conducted using a Themis Z electron microscope (Thermo Fisher Scientific, The Netherlands) equipped with a Ceta 16 CCD sensor and a corrector of spherical aberrations, which provided a maximum lattice resolution of 0.07 nm at an accelerating voltage of 200 kV.…”

“…19 In the work of Shafaghat et al, 15 the authors reported the hydrodeoxygenation of biomass oil by supercritical alcohols in the presence of supported nickel catalysts and showed that the nature of the support greatly influences the catalytic activity. 20 In the work of Shafaghat, supported Ni catalysts were studied under the conditions of bio-oil hydrogenation reaction and during regeneration. It was shown that the irreversible rearrangement of the catalyst takes place after these processes.…”