Decomposition of Pt anionic carbonyl complexes in X zeolites. Reactivity of Pto in the NO + CO reaction. Comparison with the vacuum decomposed [Pt(NH3)4]2+ complex

Abstract Pt carbonyls were created via reaction of Pt tetraamine complexes in KX and NaX zeolites with CO. The anionic [Pt 3 (CO) 6 ] 2− n Chini complexes formed inside the zeolites were thermally decomposed in vacuum and the residual carbon was combusted under low oxygen pressure followed by hydrogen reduction. Transmission electron micrographs pointed to the formation of Pt o clusters of about 2 nm in size. Carbon deposits, if not removed by oxidation, limited the NO reduction by CO. The decomposition products of anionic carbonyl complexes were compared with those of cationic Pt tetraamine complexes, and the shift of the temperature of ammonia evolution was shown to be one of the proofs of carbonyl formation.