Surface texture and physicochemical characterization of mesoporous carbon – wrapped Pd–Fe catalysts for low-temperature CO catalytic oxidation
In this paper, mesoporous carbon (meso-C) with three-dimensional mesoporous channels was synthesized through a nanocasting route using three-dimensional mesoporous silica KIT-6 as the template. Mesoporous carbon wrapped Pd–Fe nanocomposite catalysts were synthesized by the co-precipitation method. The effects of the experimental conditions, such as pH value, Fe loading content and calcination temperature, on CO oxidation were studied in detail. The prepared Pd–Fe/meso-C catalysts showed excellent catalytic activity after optimizing the experimental conditions. The surface tetravalent Pd content, existing forms of Fe species, surface chemical adsorbed oxygen concentration, and pore channels of mesoporous carbon played vital roles in achieving the highest performance for the Pd–Fe/meso-C catalyst. The reaction pathway was conjectured according to the XPS analysis of the Pd–Fe/meso-C catalysts for CO oxidation, which maybe adhered to the Langmuir–Hinshelwood + redox mechanism. The effect of moisture on CO conversion was investigated, and the superior Pd–Fe/meso-C catalyst could maintain its activity beyond 12 h. This catalyst also showed excellent activity compared to the reported values in the existing literature.