Synthesis, characterization and photocatalytic reactivities of Mo-MCM-41 mesoporous molecular sieves: Effect of the Mo content on the local structures of Mo-oxides

• Published in: Journal of catalysis Vol. 235; no. 2; pp. 272 - 278
• Main Authors: Higashimoto, Shinya, Hu, Yun, Tsumura, Rie, Iino, Kiyoshi, Matsuoka, Masaya, Yamashita, Hiromi, Shul, Yong Gun, Che, Michel, Anpo, Masakazu
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier Inc 25-10-2005; Elsevier; Elsevier BV
• Subjects: Catalysis; Chemistry; Colloidal state and disperse state; Exact sciences and technology; General and physical chemistry; Local structure of Mo-oxides; Mo-MCM-41; NO reduction; Photocatalysis; Photochemistry; Physical chemistry of induced reactions (with radiations, particles and ultrasonics); Porous materials; Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry; CO; NO reduction; Photocatalysis; Mo-MCM-41; Local structure of Mo-oxides; Characterization; Heterogeneous catalysis; Local structure; Synthesis; Oxides; Transition metal; Chemical reactivity; Porous material; Molybdenum; Mesoporosity; Molecular sieve
• ISSN: 0021-9517; 1090-2694
• DOI: 10.1016/j.jcat.2005.08.009

A series of Mo-MCM-41 mesoporous molecular sieves of varying Mo content were synthesized and the local structures of their active sites characterized by means of XRD, UV–vis, photoluminescence, and XAFS measurements. Mo-MCM-41 was found to possess three different types of Mo-oxide species, the concentrations of which were dependent on the Mo content: a highly dispersed tetra-coordinated monomeric molybdate, a tetra-coordinated dimeric and/or oligomeric molybdate, and a hexa-coordinated polymeric molybdate. Moreover, the tetra-coordinated molybdate species was observed to play a major role in the photocatalytic reduction of NO in the presence of CO to form N
2 and CO
2.