HOMOGENEOUS CATALYSIS OF THE WATER GAS SHIFT REACTION: IR, ¹H- AND 13C-NMR IN SITU STUDIES ON CATALYTIC IRIDIUM SYSTEMS
Author
Pardey,A.J.
Moreno,M.A.
Ortega,M.C.
Mendez,B.
Rivas,A.B.
Moya,S.A.
Villagra,D.
Lutz,M.
Abstract
Reported here are the in situ FT-IR and 13C-NMR spectroscopic studies of the complex cis-[Ir(CO)2(py)2](PF6 ) (py = pyridine) dissolved in 80% aqueous pyridine used as a precursor in the homogeneous catalysis of the water gas shift reaction (WGSR, CO + H2O Æ CO2 + H2). These spectroscopy studies reveal the presence of aminocarbonyliridium complexes with linear and bridging carbonyls groups as reaction intermediates. The WGSR catalysis by Ir4(CO)12 complex dissolved in 80% of aqueous 4-picoline or pyridine under 1.9 atm of CO at 100 C and the FT-IR and ¹H-NMR in situ studies of the pyridine promoted disproportionation of Ir4(CO)12, are also described