Efficient Ru-based scrap waste automotive converter catalysts for the continuous-flow selective hydrogenation of cinnamaldehyde

Abstract

Mechanochemical preparation of a novel catalyst based on Ru-containing scrap catalytic converters for the selective continuous flow hydrogenation of cinnamaldehyde.

Fe‐Co Alloyed Nanoparticles Catalyzing Efficient Hydrogenation of Cinnamaldehyde to Cinnamyl Alcohol in Water

“…Cinnamyl alcohol (COL) is an essential substance/precursor highly demanded by flavoring, perfume, and pharmaceutical industries [1–4] . To date, the industrial production of COL has been carried out exclusively via the selective hydrogenation (SH) of cinnamaldehyde (CAL) in organic solvents [5–7] .…”

“…Cinnamyl alcohol (COL) is an essential substance/precursor highly demanded by flavoring, perfume, and pharmaceutical industries. [1][2][3][4] To date, the industrial production of COL has been carried out exclusively via the selective hydrogenation (SH) of cinnamaldehyde (CAL) in organic solvents. [5][6][7] The efficient utilization of CAL is the most critical issue for COL production because large quantities of CAL can only be obtained in an economically viable manner via extraction processes from the bark of cinnamon and other CALcontaining trees with limited nature reserves.…”

Continuous flow synthesis of menthol via tandem cyclisation–hydrogenation of citronellal catalysed by scrap catalytic converters

“…This behaviour was observed also by Moores et al 34 The slightly increased activity of Fe/SCATs (A) compared to sample D (having same iron content but supported on SiO2), reported in Entry 1, can be explained in terms of higher stability of the iron nanoparticles over the smashed catalytic converters, as recently demonstrated by supporting Ru over SCATs. 36 In addition, as reported in Table 3 Entry 1, SCATs itself showed some activity in the cyclization of citronellal to isopulegols, therefore increasing the final yield to menthols, where instead silica do not have catalytic activity.…”

“…The structure of the SCATs was reported to be composed of a sequence of coats, made of alumina, silica, titania and ceria 35 and offers the possibility to support metal nanoparticles, as demonstrated in a recent work. 36 Iron oxide nanoparticles were then supported on SCATs adapting the microwave-assisted methodology previously described. 34 Washed SCATs (Cartridge 2 in Figure 2B) were directly employed as catalyst for the hydrogenation step, in order to exploit the presence of trace quantities of noble metals in the matrix, potentially highly active for hydrogenation reactions.…”

Recent Progress in Continuous‐Flow Hydrogenation

“…Another work on selective hydrogenation of 64 in continuous flow was reported by Luque and co‐workers . The authors prepared a Ru‐based catalyst (10 % Ru/C) by recycling waste ceramic‐cores of scrap automotive catalytic converters (SCATs) to use as a support.…”