Structure and catalytic performance of Mo dimer oxy-carbide species in NaYsupercages

Mo dimer oxy-carbide species were synthesized in the supercage of NaY zeoli te by adsorption of Mo(CO)(6) vapor at saturation, followed by thermal deco mposition in vacuum. TPD, EXAFS,: XPS and XRF data revealed that a Mo dimer was attached in a supercage by a saturation adsorption-thermal decompositi on at 573 K and that up to four Mo dimers in a supercage were stepwisely fo rmed without aggregation after four cycles, The Mo dimer oxy-carbide specie s exhibited a unique methanol decomposition reaction to produce CH4, CO2, a nd H-2 in an approximate ratio of 1 : 1 : 2. This reaction was characterist ic of the Mo dimer oxy-carbide species and was never observed fbr other Mo species such as oxidized and reduced Mo species in NaY supercages. (C) 2000 Elsevier Science B.V. All rights reserved.