Investigation of catalysts M/CeO2(M = Pt, Rh, or Pd) for purification of CO2derived from oxycombustion in the absence or presence of water

Oxyfuel combustion is a promising technology to produce a CO2-rich flue gas ready suitable for sequestration or valorization. But its storage as well as its further valorization requires to increase the CO(2)purification as a small amount of CO and NOx are produced during combustion. Based on the technology developed for three-way converters, similar systems, i.e., M/CeO(2)where M is Pt, Pd, or Rh, were studied for NO-CO abatement in a gas stream similar to those obtained when an oxyfuel combustion is performed. The results evidenced that the role of the metal nature influences the performances obtained on NO-CO abatement, platinum supported on ceria being the most efficient catalyst. We also measured the impact of the presence of water in the reaction stream on the catalytic activity of these materials. It appears that the presence of water has a beneficial effect on the different reactions due to a water gas shift reaction that increases the reduction of the NO and favors the formation of N-2. The study pointed out that platinum supported on ceria remained the best catalyst, under these wet operating conditions close to industrial ones, for purification of oxyfuel combustion exhausts.

Automated summary

Oxyfuel combustion technology produces CO2-rich flue gas, requiring enhanced CO2 purification efficiency and studying the effect of Pt/CeO2 on NO-CO reduction. Results showed that the presence of water benefits catalytic reactions.