Vol.:(0123456789) 1 3 Catalysis Letters https://doi.org/10.1007/s10562-019-02759-x Mixed Oxides of Hydrotalcites as Catalysts for Nopol Epoxidation Diana L. Hoyos‑Castaño 1  · Edwin Alarcón 1  · Aída Luz Villa 1 Received: 14 December 2018 / Accepted: 24 March 2019 © Springer Science+Business Media, LLC, part of Springer Nature 2019 Abstract Mixed oxides catalysts derived from Mg/Al hydrotalcite-type materials with molar ratios of 1, 2, 3 and 4 were synthesized, characterized and tested in nopol epoxidation. A combined oxidant of hydrogen peroxide and acetonitrile was used in the presence of acetone and water as solvents. Catalysts were characterized by X-ray difraction (XRD), N 2 adsorption, scanning electron microscopy (SEM), atomic absorption spectrophotometry (AAS), basicity by CO 2 -TPD, and infrared spectroscopy (FTIR). SEM analysis showed in all materials irregular non-homogeneous aggregates. Basicity of mixed oxides increased with Mg/Al ratio. The efect of temperature and basicity of the catalysts on the catalytic activity was analyzed. The best conversion and selectivity were obtained (60 °C, 2 h) over the most basic catalyst HT4C (mixed oxide Mg/Al = 4), with 99% conversion, epoxide selectivity of 38% and a selectivity of 36% to a campholenic aldehyde analogue compound, which duplicate the activity reported over a heterogeneous catalyst based on askanite–bentonite solid starting from nopol epoxide. In terms of TOF the most active catalyst, which also combines an acceptable conversion, was mixed oxide HT3C (mixed oxide Mg/Al = 3). Graphical Abstract R O R O Campholenic aldehyde (R= H) R nopol (R= CH 2 OH) α-pinene (R= H) Campholenic aldehyde derived from nopol (R= CH 2 OH) [O] [O] Isomerization Mg/Al mixed oxide 60 °C, 2 h 74% yield oxidation products Keywords Hydrotalcite-type-materials · Hydrogen peroxide · Nopol epoxide · Campholenic aldehyde analogue Extended author information available on the last page of the article