Abstract: A catalyst composition containing one or more binary oxides of palladium and rare earth metal such as Ce, La, Nd, Pr and/or Sm. The catalyst composition is used for the catalytic combustion of gaseous combustion mixtures of oxygen and carbonaceous fuels such as methane, e.g., a natural gas/air combustion mixture. Specific preferred binary oxides may be, for example, M.sub.2 O.sub.3.PdO (e.g., La.sub.2 O.sub.3.PdO) or 2M.sub.2 O.sub.3.PdO, wherein in each case M is La, Nd or Sm. A process of combusting gaseous carbonaceous fuels includes contacting a catalyst as described above under combustion conditions, e.g., 925.degree. C. to 1650.degree. C. and 1 to 20 atmospheres pressure, to carry out sustained combustion of the combustion mixture, including catalytically supported thermal combustion. Regeneration of over-temperatured M.sub.2 O.sub.3.PdO catalyst is also provided for.

Abstract: A catalyst composition containing one or more binary oxides of palladium and rare earth metal such as Ce, La, Nd, Pr and/or Sm. The catalyst composition is used for the catalytic combustion of gaseous combustion mixtures of oxygen and carbonaceous fuels such as methane, e.g., a natural gas/air combustion mixture. Specific preferred binary oxides may be, for example, M.sub.2 O.sub.3.PdO (e.g., La.sub.2 O.sub.3.PdO) or 2M.sub.2 O.sub.3.PdO, wherein in each case M is La, Nd or Sm. A process of combusting gaseous carbonaceous fuels includes contacting a catalyst as described above under combustion conditions, e.g., 925.degree. C. to 1650.degree. C. and 1 to 20 atmospheres pressure, to carry out sustained combustion of the combustion mixture, including catalytically supported thermal combustion. Regeneration of over-temperatured M.sub.2 O.sub.3.PdO catalyst is also provided for.

Abstract: A combustor for supporting the catalytic combustion of a gaseous carbonaceous fuel/air combustion mixture contains a catalyst zone in which is disposed a catalyst body comprising at least a first and a second catalyst member and further contains a downstream zone where homogeneous combustion occurs. Each catalyst member is comprised of a carrier body having a catalyst material deposited thereon. The first carrier is made of a silica-magnesia-alumina material comprised primarily of cordierite, mullite and corundum and the second carrier is made of a ceramic fiber matrix material comprising ceramic (alumina-boron oxide-silica) fibers in a silicon carbide matrix.

Abstract: A catalyst bed (30) for a combustor (18) for supporting the catalytic combustion of a gaseous air/fuel (e.g., methane or natural gas) combustion mixture contains an igniter catalyst member (1) upstream of a promoter catalyst member (2). The catalyst members each comprise carrier monoliths, the igniter catalyst member (1) having an igniter catalyst material deposited thereon and the promoter catalyst member (2) having a promoter catalyst material deposited thereon. The igniter catalyst material is distinguished from the promoter catalyst material in one or more of the following ways: the igniter catalyst material may have (a) a higher catalytic activity for combustion of the air/fuel mixture, (b) a lower catalyst deactivation temperature than the promoter catalyst material, and/or (c) the promoter catalyst regeneration temperature range brackets the upper limit of the regeneration temperature range of the igniter catalyst.

Abstract: A catalyst composition containing one or more binary oxides of palladium and rare earth metal such as Ce, La, Nd, Pr and/or Sm. The catalyst composition is used for the catalytic combustion of gaseous combustion mixtures of oxygen and carbonaceous fuels such as methane, e.g., a natural gas/air combustion mixture. Specific preferred binary oxides may be, for example, M.sub.2 O.sub.3.sup.. PdO (e.g., La.sub.2 O.sub.3.sup.. PdO) or 2M.sub.2 O.sub.3.sup.. PdO, wherein in each case M Is La, Nd or Sm. A process of combusting gaseous carbonaceous fuels includes contacting a catalyst as described above under combustion conditions, e.g., 925.degree. C. to 1650.degree. C. and 1 to 20 atmospheres pressure, to carry out sustained combustion of the combustion mixture, including catalytically supported thermal combustion. Regeneration of over-temperatured M.sub.2 O.sub.3.sup.. PdO catalyst is also provided for.

Abstract: A process for operating a palladium oxide-containing catalytic combustor is useful, e.g., for powering a gas turbine. The palladium oxide is supported on a metal oxide such as alumina, lanthanide metal oxide-modified alumina, ceria, titania or tantalum oxide. The method involves maintaining control of the temperature within the combustor in such a manner as to insure the presence of palladium oxide. By maintaining the temperature below the decomposition onset temperature of palladium oxide (which is catalytically active for catalytic combustion) into metallic palladium (which is catalytically inactive) deactivation of the catalyst is avoided and high catalytic activity is retained. Regeneration of catalyst following inactivation resulting from an over-temperature is accomplished by using a heat soak in a regeneration temperature range which varies depending on the particular metal oxide used to support the palladium oxide.

Abstract: A method for operating a palladium oxide containing catalytic combustor useful, e.g., for powering a gas turbine, wherein the palladium oxide is supported on a metal oxide such as alumina, ceria, titania or tantalum oxide. The method involves maintaining control of the temperature within the combustor in such a manner as to insure the presence of palladium oxide. By maintaining the temperature below about 800.degree. C. decomposition of palladium oxide into metallic palladium is avoided and high catalytic activity is retained. Regeneration of catalyst following inactivation resulting from an over-temperature is accomplished by using a heat soak in a temperature range which varies depending on the metal oxide used to support the palladium oxide.

Abstract: A novel praseodymium-palladium oxide compound has the formula Pr.sub.4 PdO.sub.7. The compound has utility as a catalyst for oxidation of combustion mixtures comprising oxygen (e.g., air) and gaseous carbonaceous fuels such as methane and displays excellent regeneration characteristics after exposure to decomposition-causing temperatures. The compound may be used in a catalyst composition by being coated as a washcoat on a suitable carrier. Catalytic combustion processes are carried out by contacting such combustion mixture with the catalyst under combustion conditions, including catalytically supported thermal combusiton. Regeneration of over-temperatured catalyst is also provided for.

Abstract: A novel praseodymium-palladium oxide compound has the formula Pr.sub.4 PdO.sub.7. The compound has utility as a catalyst for oxidation of combustion mixtures comprising oxygen (e.g., air) and gaseous carbonaceous fuels such as methane and displays excellent regeneration characteristics after exposure to decomposition-causing temperatures. The compound may be used in a catalyst composition by being coated as a washcoat on a suitable carrier. Catalytic combustion processes are carried out by contacting such combustion mixture with the catalyst under combustion conditions, including catalytically supported thermal combustion. Regeneration of over-temperatured catalyst is also provided for.

Abstract: A method for operating a palladium oxide containing catalytic combustor useful, e.g., for powering a gas turbine. The method involves maintaining control of the temperature within the combustor in such a manner as to insure the presence of palladium oxide. By maintaining the temperature below about 800.degree. C. decomposition of palladium oxide into metallic palladium is avoided and high catalytic activity is retained. Regeneration of catalyst following inactivation resulting from an over-temperature is accomplished by using a heat soak in the temperature range of about 530.degree. C.-650.degree. C.