Preparation and characterization of Pd loaded Sr-deficient K2NiF4-type (La, Sr)2MnO4 catalysts for NO–CO reaction

Investigation of catalysts M/CeO2 (M = Pt, Rh, or Pd) for purification of CO2 derived 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 CO₂ 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/CeO₂ 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 N₂. 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.

A review of the catalysts used in the reduction of NO by CO for gas purification

The reduction of NO by the CO produced by incomplete combustion in the flue gas can remove CO and NO simultaneously and economically. However, there are some problems and challenges in the industrial application which limit the application of this process. In this work, noble metal catalysts and transition metal catalysts used in the reduction of NO by CO in recent years are systematically reviewed, emphasizing the research progress on Ir-based catalysts and Cu-based catalysts with prospective applications. The effects of catalyst support, additives, pretreatment methods, and physicochemical properties of catalysts on catalytic activity are summarized. In addition, the effects of atmosphere conditions on the catalytic activity are discussed. Several kinds of reaction mechanisms are proposed for noble metal catalysts and transition metal catalysts. Ir-based catalysts have an excellent activity for NO reduction by CO in the presence of O₂. Cu-based bimetallic catalysts show better catalytic performance in the absence of O₂, in that the adsorption and dissociation of NO can occur on both oxygen vacancies and metal sites. Finally, the potential problems existing in the application of the reduction of NO by CO in industrial flue gas are analyzed and some promising solutions are put forward through this review.

Co2+ substituted La2CuO4/LaCoO3 perovskite nanocomposites: synthesis, properties and heterogeneous catalytic performance

Cobalt substituted La₂CuO₄/LaCoO₃ perovskite nanocomposites were prepared using a microwave combustion method.