Study of propene metathesis on MoO3−x/Al2O3 catalysts; effect of diazomethane decomposition

✍ Scribed by M. Ghazi; W. M. H. Sachtler

• Publisher: Elsevier Science
• Year: 2010
• Tongue: English
• Weight: 414 KB
• Volume: 109
• Category: Article
• ISSN: 0165-0513
• DOI: 10.1002/recl.19901090209

✦ Synopsis

Abstract

Propene metathesis has been studied at 295 K and 1 atm in He or in H~2~ with MoO~3−x~/Al~2~O~3~ catalysts which were reduced at 673 K. Some catalysts were modified by exposing them to diazomethane vapor prior to testing. The diazomethane was synthesized shortly before use; it was stored by dissolving its vapor in di‐n‐butyl phthalate. Metathesis of the unmodified catalysts revealed an induction period during which the activity increased; this period is markedly shorter in H~2~ than in He. In He, metathesis is the sole reaction, in H~2~ it is accompanied by a prevailing hydrogenolysis. No induction period is visible for catalysts modified with diazomethane in accordance with the assumption that surface carbenes are reaction intermediates. The activity is, however, lowered by this treatment, as catalyst deactivation is enhanced by the pretreatment with diazomethane.