The physicochemical and catalytic properties of clay extrudates in cyclization of citronellal
: Vajglová Zuzana, Simakova Irina L., Eränen Kari, Mäki-Arvela Päivi, Kumar Narendra, Peurla Markus, Tolvanen Stiina, Efimov Alexander, Hupa Leena, Peltonen Jouko, Murzin Dmitry Y.
Publisher: Elsevier B.V.
: 2022
Applied Catalysis A: General
: Applied Catalysis A: General
: 118426
: 629
: 0926-860X
DOI: https://doi.org/10.1016/j.apcata.2021.118426
: https://www.sciencedirect.com/science/article/pii/S0926860X21004403
: https://research.utu.fi/converis/portal/detail/Publication/174612428
Four clay materials, namely, bentonite, bleaching earth, attapulgite and sepiolite, were shaped into the cylindrical body by extrusion. Clays were characterized in depth by TEM, SEM-EDX, N2 physisorption, pyridine FTIR, pH measurements, contact angle measurements, 27Al MAS NMR, and the crush test. Catalytic properties were investigated in the citronellal cyclization as a model reaction. The reaction was performed in the trickle-bed reactor at 70 °C, 10 bar of Ar with 0.086 M initial citronellal concentration in cyclohexane. The best results were obtained over attapulgite with isopulegols yield of 24% and stereoselectivity to the desired isopulegol isomer of 61%. Attapulgite had the highest meso-to-micropore volume ratio, the highest basicity, a low Brønsted-to-Lewis acid sites ratio, and the lowest amount of Brønsted acid sites compared to other extrudates. In addition, same clay exhibited the highest mechanical strength of extrudates.