Novel N-interstitial re-cluster catalysts supported on HZSM-5 for direct phenol synthesis from benzene and molecular oxygen

INOR 872

Mizuki Tada, mtada@chem.s.u-tokyo.ac.jp, Rajaram Bal, Takehiko Sasaki, Yohei Uemura, and Yasuhiro Iwasawa, iwasawa@chem.s.u-tokyo.ac.jp. Department of Chemistry, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan
We have prepared N-interstitial Re-cluster catalysts supported on HZSM-5 by CVD of methyltrioxorhenium and subsequent treatment with ammonia, which are highly selective for direct phenol synthesis from benzene with molecular oxygen. Ammonia reduced Re7+ species and produced active N-interstitial Re clusters in the zeolite framework. The catalytic phenol synthesis proceeds with selectivity of 94%, which is the highest selectivity thus far. The catalytic reaction mechamism of the benzene oxidation and the role of ammonia for the catalysis are also demonstrated by means of XPS, XAFS, and DFT calculations. The N-interstitial Re clusters converted to Re7+ monomers, which were inactive for the selective oxidation, after the reaction with benzene and molecular oxygen. The formed inactive Re monomers smoothly converted to the active Re clusters by ammonia during the catalytic reaction.
 

Inorganic Catalysts
8:30 AM-11:50 AM, Wednesday, 13 September 2006 Moscone Center -- Room 302, Oral

Division of Inorganic Chemistry

The 232nd ACS National Meeting, San Francisco, CA, September 10-14, 2006