Continuous synthesis of menthol from citronellal and citral over Ni-beta-zeolite-sepiolite composite catalyst
: Simakova Irina, Mäki-Arvela Päivi, Martinez-Klimov Mark, Muller Joseph, Vajglova Zuzana, Peurla Markus, Eränen Kari, Murzin Dimitry Yu.
Publisher: Elsevier B.V.
: 2022
: Applied Catalysis A: General
: Applied Catalysis A: General
: 118586
: 636
: 0926-860X
: 1873-3875
DOI: https://doi.org/10.1016/j.apcata.2022.118586
: https://doi.org/10.1016/j.apcata.2022.118586
: https://research.utu.fi/converis/portal/detail/Publication/175134876
One-pot continuous synthesis of menthols both from citronellal and citral was investigated over 5 wt% Ni supported on H-Beta-38-sepiolite composite catalyst at 60–70 °C under 10–29 bar hydrogen pressure. A relatively high menthols yield of 53% and 49% and stereoselectivity to menthol of 71–76% and 72–74% were obtained from citronellal and citral respectively at the contact time 4.2 min, 70 °C and 20 bar. Citral conversion noticeably decreased with time-on-stream under 10 and 15 bar of hydrogen pressure accompanied by accumulation of citronellal, the primary hydrogenation product of citral, practically not affecting selectivity to menthol. A substantial amount of defuctionalization products observed during citral conversion, especially at the beginning of the reaction (ca. 1 h), indicated that all intermediates could contribute to formation of menthanes. Ni/H-Beta-38-sepiolite composite material prepared by extrusion was characterized by TEM, SEM, XPS, XRD, ICP-OES, N2 physisorption and FTIR techniques to