Cascade transformations of (±)-citronellal to menthol over extruded Ru-MCM-41 catalysts in a continuous reactor

Abstract

Cascade transformations of ()-citronellal in a continuous mode was investigated over a bifunctional shaped ruthenium catalyst bearing metal clusters of the size 7 - 13 nm. Four types of Ru/H-MCM-41...

Diffusion measurements of hydrocarbons in H-MCM-41 extrudates with pulsed-field gradient nuclear magnetic resonance spectroscopy

“…These operations resulted in a partial blockage of the micropore mouths, lower micropore volumes and grain boundary interactions between H-MCM-41 and the Bindzil binder. This is in line with the literature 7,20–22,27–33 and SEM analysis (Fig. 3).…”

“…Extrusion in practice is done from suspensions containing various additives (binders, porogens, rheology improvers, peptizers, etc). The strategy for catalyst preparation by extrusion, adopted by the authors previously, 20 included along other recipes, preparation of a mechanical mixture of the binder and the catalytic phase by mechanical mixing, drying, calcination and grinding. This final mixture in a powder form, which already experienced mechanical impact leading to alteration of physico-chemical properties, underwent extrusion.…”

“…Extrudates were prepared using the weight ratio of the catalyst/water/methylcellulose of 33/65/2 as a suspension for extrusion and catalyst shaping. 20,21 The extrudates were shaped in the one-screw extrusion device (TBL-2, Tianjin Tianda Beiyang Chemical Co. Ltd., China) into the cylindrical shapes with a diameter of 1.5 mm. After drying (at 110 °C for 7 h) and calcination (at 500 °C for 4 h), the extrudates were cut to a length of ca.…”

Continuous Flow Hydrogenation of Flavorings and Fragrances Using 3D-Printed Catalytic Static Mixers

“…We focused our studies on six model compounds: vinyl acetate, coumarin, (−)-isopulegol, cinnamaldehyde, citronellal, and linalool, with some consideration of the fragrances eugenol, estragole, and benzaldehyde. The hydrogenation reactions of vinyl acetate, coumarin, − cinnamaldehyde, − citronellal, , and (−)-isopulegol , have been previously realized in continuous flow, but, to the best of our knowledge, never over additively manufactured catalysts or catalyst supports. We tested the hydrogenation of these six molecules over five sets of CSMs coated with one of four different metal catalyst species, namely palladium, platinum, ruthenium, and nickel.…”

Heterogeneous Catalytic Conversion of Citronellal into Isopulegol and Menthol: Literature Review

“…In addition, for the hydrogenation step, the study from Nie et al, 2006 showed an increasing Ni loading from the Ni/BEA (Fatimah et al, 2015) catalysts that leads to faster hydrogenation and selectivity to produce menthol in a one-pot conversion. Particularly, the hydrogenation rate was insigni cantly in uenced by the increasing particle size, for example, in the Ru-deposited material on MCM-41 (Vajglová et al, 2020) , and Pt-Ga-MCM-41 (Balu et al, 2010) . The nanoparticles formed from active metals demonstrated a highly stable catalytic activity, as represented by better reusability (Balu et al, 2010;Fatimah et al, 2019).…”