The conversion of α-pinene to cis-pinane from buzai232's blog

The conversion of α-pinene to cis-pinane

The concept of a solid catalyst coated with a thin ionic liquid layer (SCILL) was applied to the stereoselective hydrogenation of α-pinene. Nickel, a non-noble metal, was supported on a discarded fluid catalytic cracking catalyst (DF3C) and then modified with different loadings of the ionic liquid 1-ethanol-3-methylimidazolium tetrafluoroborate ([C2OHmim][BF4]). The resulting catalysts showed a range of conversions and selectivities for the hydrogenation of α-pinene. The SCILL catalysts afforded cis-pinane with high selectivity and their activity depended on the ionic liquid loading. For an ionic liquid loading of 10 wt%, although the catalytic activity was suppressed, the selectivity and conversion could reach above 98% and 99%, respectively. In addition, the catalyst remained stable after 13 runs and the activity was almost unchanged with the conversion maintained at approximately 99%. Thus, the ionic liquid layer not only improved the selectivity for cis-pinane but also protected the active site of the catalyst and prolonged the service lifetime of the catalyst. The SCILL catalytic system provides an example of an ionic liquid catalytic system which eliminates organic solvents from the catalytic process.Get more news about cis pinane,you can vist our website!

As a natural, green, and renewable product, α-pinene has drawn great interest for applications in the pharmaceutical, bioenergy, fine chemistry, and flavouring industries.1 There are two kinds of hydrogenation products of α-pinene, namely, cis-pinane and trans-pinane, and among these two products, cis-pinane is more desirable since the content of cis-pinane in raw materials should be greater than 90% to reduce by-products and simplify post-treatments. There is a need to design and identify more effective catalysts for the selective hydrogenation of α-pinene to improve the yield of cis-pinane. To date, various studies have focused on hydrogenation of α-pinene, including a report by Hou et al. on Ru nanoparticles in aqueous micellar microreactors as catalysts with a high selectivity for cis-pinane under mild conditions.2 Milewska et al. studied biphasic hydrogenation of α-pinene over Pd/C under a high pressure of carbon dioxide.3 Deliy et al. reported that hydrogenation and isomerization of pinenes occur simultaneously on Ru/C, Rh/C, Pt/C, and Ir/C catalysts.4 Selka et al. achieved excellent catalytic activity and selectivity based on their studies into hydrogenation of α-pinene over Pd-based catalysts on different supports; however, the reusability of these catalysts was poor.1 Simakova et al. investigated the hydrogenation of α-pinene over 4 wt% palladium on carbon (Pd/C) as a catalyst with n-octane as a solvent.5 Tanielyan et al. used ethanol as solvent in their studies of pinene hydrogenation over anchored Wilkinson catalyst.6 However, noble metal catalysts and organic solvents are expensive, environmentally unfriendly, and the lack of reusability of these catalysts poses major challenges.
Discarded fluid catalytic cracking catalyst (DF3C) is a kind of industrial waste product from petroleum refining processes. DF3C contains heavy metals such as iron, nickel, and vanadium, which were contained in the heavy oil subjected to the reactions. A large amount of DF3C is produced every year, the majority of which is sent to landfill, risking environmental pollution, from heavy metals seeping into groundwater.7 Recently, attention has been paid to recovering DF3C, and it has been applied as a catalyst for cracking of waste plastics,8 a source of heavy metals,7 and rare earth elements.11,12 DF3C is mainly composed of Al2O3, SiO2, and residual nickel, with a rich pore structure and large specific surface area; hence, DF3C might act as an effective active metal carrier.