Effect of noble metal addition to alkali-exchanged cryptomelane on the simultaneous soot and VOC combustion activity

摘要

A series of catalysts based on cryptomelane (AMn(8)O(16)) containing different alkali cations (A = H+, Na+, K+ or Rb+) were synthesized, characterized and tested for their soot and VOC combustion activity. The K-OMS material with the lowest work function and highest catalytic activity was then functionalized with 2 wt% noble metal (Ag, Au or Pt) and evaluated for its soot and VOC combustion activity. The results showed the superiority of Ag/K-OMS for soot oxidation (50% soot conversion at 440 degrees C) and that of Pt/K-OMS for hydrocarbon total oxidation (ca. 100% methane conversion at 450 degrees C and propane conversion at 350 degrees C), suggesting that both noble metals are necessary for the simultaneous removal of soot and VOCs.