Polycarbonyl species in Pt/H-ZSM-5:: FTIR spectroscopic study of 12CO-13CO co-adsorption

In this work, we report on the formation of several non-classical carbonyls of platinum produced after CO adsorption on Pt/H-ZSM-5. These are: (i) two kinds of Pt3+(CO)(2) dicarbonyls (v(s) at 2212 cm(-1) and v(as) at 2176 cm(-1); v(s) at 2196 cm(-1) and v(as) at ca. 2155 cm(-1)), which are decomposed without producing monocarbonyls; (ii) Pt2+-Co (2150 cm(-1)), which form dicarbonyls at high CO coverages; (iii) Pt+(CO)(3) complexes (2161, 2153 and 2110 cm(-1)) which easily lose one CO ligand even at room temperature, being thus converted to Pt+(CO)2 (2122 and 2092 cm(-1)). The latter are thermally decomposed without producing monocarbonyls. In addition, carbonyls of metallic platinum have been found. (C) 2005 Elsevier B.V. All rights reserved.