Synthesis and characterization of cobalt modified LTL-type zeolite Original Research Article

Cobalt modified LTL-type zeolite (K-CoL) was hydrothermally synthesized, partially substituting framework aluminum for cobalt atoms. The isomorphous substitution of cobalt into the zeolite structure was confirmed by XRD, TGA, UV–VIS, XPS and chemical analyses. Cobalt ions were removed together with K+ following NH4Cl exchange, indicating Co2+ also to be present as balancing or occluded cations into the channels of K-CoL. The epoxidation of R-(+)-limonene in the presence of a sacrificial aldehyde over K-CoL yields 70.7% cis-1,2-epoxide. Besides, the activity of reused K-CoL was more stable after three consecutive runs than a Co impregnated sample containing the same amount of cobalt as in K-CoL.