Stable hetero-metal doped Co-based catalysts prepared by electrodeposition method for low temperature combustion of toluene

Abstract

A series of hetero-metal (Ni, Mn, and Cu) doped Co-based catalysts were prepared by a unipolar pulse electro-deposition (UPED) method and applied for the catalytic combustion of toluene. It is found that hetero-metal doping significantly influenced the morphology and surface elemental compositions of Co-based catalysts, and the increase in the contents of Ni and Mn elements made a negative influence on the catalyst structure. H2-TPR and O2-TPD analysis results suggested that the hetero-metal doping enhanced the low temperature reducibility and resulted in the formation of lattice defects, which were favorable to generate more easily reducible species and facilitate the oxygen mobility, thereby improved the performance for the catalytic combustion of toluene. Especially, the Co-Cu/NF catalyst performed the best catalytic activity with the lowest toluene conversion temperature of T90 at 248 °C, which should be contributed by its low-temperature reducibility, increased surface and lattice oxygen species, and high content of active Co3+ species promoted by the interaction of the mixed metal oxides. Moreover, the Co-Cu/NF also performed excellent catalytic stability and high selectivity to CO2 in the presence and absence of water vapor for the catalytic combustion of toluene for a long term.