Nickel- and/or iron-based ceria-supported catalysts for CO oxidation in combustion exhaust gases

We present a series of Ni, Fe, and mixed NiFe-based catalysts, deposited onto ceria prepared with either soft templated (with CTAB) or hard templated (with SBA-15) syntheses. The prepared materials were thoroughly characterized with SEM, HRTEM, EDX, ICP-MS, PXRD, and N2 adsorption techniques, to fully comprehend their physicochemical properties. All catalysts were then tested for carbon monoxide oxidation reaction at different temperatures, aiming to reach temperature and feed composition conditions typical of combustion exhausts from industrial and power plants (350-400 ◦C, in the presence of competitive species such as CO2 and H2O in the feed). Advanced reaction tests highlighted outstanding materials (especially NiFe catalyst deposited onto hard templated ceria), displaying catalytic performances able to compete with those typical of noble metal–based catalysts. Such catalysts were further investigated by means of Raman, NEXAFS, H2-TPR, and CO-FTIR, unraveling their surface and reduction properties, which make them excellent candidates for replacing more costly noble metal-based catalysts currently employed for CO oxidation reaction.