1. The physicochemical and catalytic properties of clay extrudates in cyclization of citronellal
- Author
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Zuzana Vajglová, Jouko Peltonen, Markus Peurla, Päivi Mäki-Arvela, Alexander Efimov, Dmitry Yu. Murzin, Leena Hupa, Kari Eränen, Irina L. Simakova, Stiina Tolvanen, Narendra Kumar, Tampere University, and Materials Science and Environmental Engineering
- Subjects
Cyclohexane ,Process Chemistry and Technology ,Sepiolite ,215 Chemical engineering ,Catalysis ,chemistry.chemical_compound ,chemistry ,Physisorption ,Yield (chemistry) ,Bentonite ,Citronellal ,Brønsted–Lowry acid–base theory ,Nuclear chemistry - Abstract
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. publishedVersion
- Published
- 2022