Comparison studies of in situ loaded and impregnated silicalite-cobalt oxides

Abstract Data are presented which strongly indicate that cobalt has been incorporated into the framework of Silicalite. Experiments conducted to substantiate this claim are ion exchange, thermogravimetric, ammonia desorption, UV-visible spectrography, and catalytic activity for 2-propanol and hexane decomposition. Propylene is formed from 2-propanol for the hydrogen form of samples in situ loaded for cobalt compositions less than 4%. For hexane decomposition the reactions appear to be dehydrogenation of hexane to hexene and cracking of hexene to propylene followed by further decomposition to methane. The production of methane for samples with Co greater than 1% is high. However, the active sites for the in situ loaded catalyst are very difficult to reduce and appear to be different than the impregnated Co samples.