Catalytic Cooperation between MoO 3 and Sb204 in N-Ethyl Formamide Dehydration

BING ZHOU; EDGARDO SHAM; TADEUSZ MACHEJ; PATRICK BERTRAND; PATRICIO RUIZ,; B. DELMON

JOURNAL OF CATALYSIS

ACADEMIC PRESS INC ELSEVIER SCIENCE

Lugar: Amsterdam; Año: 1991 vol. 132 p. 157 - 182

0021-9517

Catalysts containing M003 and a-Sb204 with different "architectures" were prepared by different methods: mixing of separately prepared pure oxides, impregnation of M003 by Sb204 or vice versa. We report results obtained in the oxygen-aided dehydration of N-ethyl formamide catalyzed by these solids. A strong synergy between Mo and Sb is always observed. Extensive characterization of the catalysts before and after catalytic test, by X-ray diffraction, Electron Microscopy, Analytical Electron Microscope, XPS, and Ion Scattering Spectroscopy excludes the formation of mixed oxides or solid solutions as well as mutual contamination. Rather, the artificial contamination created by impregnation with a precursor of the other oxide exhibits a strong tendency to disappear. The catalytic synergy persists after the contamination has disappeared. The origin of the observed synergy is attributed to a remote control mechanism, namely spillover oxygen produced by ct-Sb204 creates and/or regenerates active and selective sites on MOO3.