Catalytic activity of powder and monolith perovskites in methane combustion

Honeycomb monolith perovskite catalysts were prepared from ultradispersed p owders of mixed oxides of rare-earth metals (La-Ce or Dy-Y) and transition metals (Ni, Fe, Mn) by mechanochemical methods. A plasmochemical method was used to obtain La-Ni containing monoliths. The catalytic activity of powde rs and monoliths was compared in the catalytic combustion of methane. The i ntrinsic catalytic properties of the active components (apparent kinetic co nstant and energy of activation) were not significantly affected by the man ufacturing procedure of monoliths in a large range of temperatures. Best pe rformance was exhibited by La-Ni oxides containing monoliths which possess the highest pore volume and fraction of macropores. (C) 1999 Elsevier Scien ce B.V. All rights reserved.