Cooperative catalysis of palladium nanoparticles and cobalt oxide support for formylation of aryl iodides under syngas atmosphere

Formylation of aryl iodides proceeded effectively in the presence of palladium nanoparticles on cobalt oxide under a syngas atmosphere to afford aldehydes up to 91% yield. A cooperative effect between palladium nanoparticles and cobalt species derived from the support was integral to efficient transformation. Both palladium and cobalt were revealed to exist as zero valent metals after H₂ treatment from X-ray absorption near edge structure and X-ray diffraction spectra. The catalyst could be reused at least 7 times without significant loss of activity.