The Nature of the cobalt salts affects the catalytic properties of promoted VPO

LAURA CORNAGLIA, CARLOS CARRARA, JUAN PETUNCHI, EDUARDO LOMBARDO

STUDIES IN SURFACE SCIENCE AND CATALYSIS

Elsevier

Año: 2000 vol. 130 p. 1727 - 1732

0039-3037

 obalt-impregnated VPO catalysts containing 2 and 4% of the metal by weight were prepared using two different cobalt salts. The catalytic tests showed that cobalt impregnation significantly increased the overall activity. The use of cobalt acetylacetonate led to a more selective high loading catalyst. To investigate the origin of the cobalt effect, the solids were characterized using XRD, Raman Spectroscopy, FTIR and XPS. No structural effects were detected through XRD. After several hundred hours on stream, the only phase detected inall cases was V(IV) vanadyl pyrophosphate. The surface oxidation state of vanadium was V(IV). The Co 2p XPspectrum has an intense shoulder at 788 eV, indicating that Co(II) species are present.