Thermo-Exfoliated Graphite Containing CuO/Cu2(OH)3NO3:(Co2+/Fe3+) Composites: Preparation, Characterization and Catalytic Performance in CO Conversion

Thermo-exfoliated graphite (TEG)/CuO/Cu2(OH)3NO3:(Co/Fe) composites were prepared using a wet impregnation method and subsequent thermal treatment. The physicochemical characterization of the composites was carried out by powder X-ray diffraction (PXRD), scanning electron microscopy (SEM) and Ar temperature-desorption techniques. The catalytic efficiency toward CO conversion to CO2 was examined under atmospheric pressure. Characterization of species adsorbed over the composites taken after the activity tests were performed by means of temperature programmed desorption massspectrometry (TPD MS). (TEG)/CuO/Cu2(OH)3NO3:(Co/Fe) composites show superior performance results if lower temperatures and extra treatment with H2SO4 or HNO3 are used at the preparation stages. The catalytic properties enhancements can be related to the Cu2(OH)3NO3 phase providing reaction centers for the CO conversion. It has been found that prevalence of low-temperature states of desorbed CO2 over high-temperature ones in the TPD MS spectra is characteristic of the most active composite catalysts.