Abstract: Provided are improved carbon monoxide removal articles and processes for treating hydrogen gas streams to achieve very low threshold levels of carbon monoxide. The articles have a substrate with an inlet end, an outlet end, a length extending between the inlet end to the outlet end, wall elements and a plurality of cells defined by the wall elements. A first layer is deposited on the wall elements from the inlet end and extending at least partially toward the outlet end. The first layer has a preferential carbon monoxide oxidation catalyst. A second layer contains a methanation catalyst, and is deposited on at least part of the first layer from the outlet end. The second layer has a length that is about 10-70% of the substrate length.

Abstract: Provided are improved carbon monoxide removal articles and processes for treating hydrogen gas streams to achieve very low threshold levels of carbon monoxide. The articles have a substrate with an inlet end, an outlet end, a length extending between the inlet end to the outlet end, wall elements and a plurality of cells defined by the wall elements. A first layer is deposited on the wall elements from the inlet end and extending at least partially toward the outlet end. The first layer has a preferential carbon monoxide oxidation catalyst. A second layer contains a methanation catalyst, and is deposited on at least part of the first layer from the outlet end. The second layer has a length that is about 10–70% of the substrate length.

Abstract: A hydrocarbon gas such as methane and LPG is desulfurized in the presence of oxygen and an oxidation catalyst to convert sulfur compounds in the gas to sulfur oxides. The sulfur oxides are then trapped downstream of the oxidation by an adsorbent. The amount of oxygen added to the hydrocarbon gas to promote oxidation is such that the sulfur compounds are selectively oxidized and the oxidation of the hydrocarbon gas is minimized to reduce hydrogen formation.

Abstract: Provided is a fuel cell having a selective CO oxidation catalyst with an electronically conductive, particulate support dispersed on a gas diffusion membrane, and a membrane electrode assembly. Also provided is a method of supplying a purified reformate gas to a membrane electrode assembly. The method includes contacting a reformate gas comprising H2 and CO with a gas diffusion membrane while simultaneously adding an oxidant to the reformate gas to convert at least some of the CO to CO2 to form the purified reformate gas. Dispersed on the gas diffusion membrane is a selective CO oxidation catalyst with an electronically conductive, particulate support. The purified reformate gas is then passed to the membrane electrode assembly.

Abstract: The invention provides processes for selectively oxidizing carbon monoxide from an input gas stream that contains carbon monoxide, oxygen and hydrogen. The process includes the step of contacting the input gas stream with a preferential oxidation catalyst. The preferential oxidation catalysts are copper-based catalysts containing low concentrations of platinum group metals. In some embodiments, the processes of the invention are conducted using preferential oxidation catalysts having an oxide support on which is dispersed copper or an oxide thereof, a platinum group metal and a reducible metal oxide. In other embodiments, the processes of the invention are conducted with a preferential oxidation catalysts having a cerium oxide support on which is dispersed copper or an oxide thereof and a platinum group metal.

Abstract: A hydrocarbon gas such as methane and LPG is desulfurized in the presence of oxygen and an oxidation catalyst to convert sulfur compounds in the gas to sulfur oxides. The sulfur oxides are then trapped downstream of the oxidation by an adsorbent. The amount of oxygen added to the hydrocarbon gas to promote oxidation is such that the sulfur compounds are selectively oxidized and the oxidation of the hydrocarbon gas is minimized to reduce hydrogen formation.

Abstract: Provided are improved carbon monoxide removal articles and processes for treating hydrogen gas streams to achieve very low threshold levels of carbon monoxide. The articles have a substrate with an inlet end, an outlet end, a length extending between the inlet end to the outlet end, wall elements and a plurality of cells defined by the wall elements. A first layer is deposited on the wall elements from the inlet end and extending at least partially toward the outlet end. The first layer has a preferential carbon monoxide oxidation catalyst. A second layer contains a methanation catalyst, and is deposited on at least part of the first layer from the outlet end. The second layer has a length that is about 10-70% of the substrate length.

Abstract: A sulfur sorber for the reduction of gaseous sulfur compounds, e.g., H2S, in a gas stream The sulfur sorber, e.g., zinc oxide, is present in the form of one or more layers on the surface of a monolith carrier, e.g., cordierite. The layers have a total thickness of at least 3 g/in3 of the carrier. Preferably, the sorber is present in the form of at least three layers on the surface of the monolith carrier.

Abstract: A process for the reduction of gaseous sulfur compounds in gaseous streams. The gaseous stream is contacted with a sorber, e.g., zinc oxide, which is capable of sorbing the sulfur compounds under sulfur sorbing conditions. The sorber is present in the form of one or more layers on the surface of a monolith carrier, e.g., cordierite. The layers of the sorber have a total thickness of at least 3 g/in3 of the carrier. The process is especially useful for the removal of gaseous sulfur compounds such as H2S from gaseous streams.

Abstract: The invention provides copper-based preferential oxidation catalysts containing low concentrations of platinum group metals. In some embodiments, the catalysts of the invention have an oxide support on which is dispersed copper or an oxide thereof, a platinum group metal and a reducible metal oxide. In other embodiments, the catalysts have a cerium oxide support on which is dispersed copper or an oxide thereof and a platinum group metal. The catalysts serve as effective preferential oxidation catalyst that selectively oxidize carbon monoxide with minimal consumption of hydrogen. In some embodiments the catalysts of the invention are able to achieve levels of carbon monoxide below 10 ppm in output gas streams containing hydrogen operating with wide temperature ranges. The invention also provides apparatus, such as fuel processors, that supply hydrogen to a fuel cell, that incorporate the preferential oxidation catalysts.

Abstract: Provided is a ruthenium-based catalyst having from about 1 to 10 wt. % of a ruthenium component and at least about 0.5 wt. % of zinc oxide. In one embodiment of the catalyst, zinc oxide itself serves as a support on which the ruthenium is dispersed. In another embodiment, the ruthenium component and the zinc oxide are dispersed on a refractory oxide support other than zinc oxide. In a process aspect, the ruthenium-based catalyst can serve as a preferential oxidation catalyst in processes for removing carbon monoxide from an input gas stream containing carbon monoxide, hydrogen and oxygen. The invention also provides articles wherein multi-stage preferential oxidation processes for removal of carbon monoxide from hydrogen streams can be conducted.

Abstract: The invention provides processes for selectively oxidizing carbon monoxide from an input gas stream that contains carbon monoxide, oxygen and hydrogen. The process includes the step of contacting the input gas stream with a preferential oxidation catalyst. The preferential oxidation catalysts are copper-based catalysts containing low concentrations of platinum group metals. In some embodiments, the processes of the invention are conducted using preferential oxidation catalysts having an oxide support on which is dispersed copper or an oxide thereof, a platinum group metal and a reducible metal oxide. In other embodiments, the processes of the invention are conducted with a preferential oxidation catalysts having a cerium oxide support on which is dispersed copper or an oxide thereof and a platinum group metal.

Abstract: A process for the reduction of gaseous sulfur compounds in gaseous streams. The gaseous stream is contacted with a sorber, e.g., zinc oxide, which is cable of sorbing the sulfur compounds under sulfur sorbing conditions. The sorber is present in the form of one or more layers on the surface of a monolith carrier, e.g., cordierite. The layers of the sorber have a total thickness of at least 3 g/in3 of the carrier. The process is especially useful for the removal of gaseous sulfur compounds such as H2S from gaseous streams.

Abstract: A method to remove sulfur compounds from a gas having up to about 30 percent propylene. The gas is contacted with a zeolite compound at greater than 75° C. The zeolite compound comprises less than 5 percent water. Useful zeolites include X, Y and faujasite. The zeolite can ion exchanged with ions such as zinc ion.

Abstract: Provided is a trap and method for removing hydrogen sulfide from a gas stream. The hydrogen sulfide trap includes a monolith substrate on which is disposed zinc oxide, and a second metal or oxide thereof. In some aspects, the hydrogen sulfide trap is advantageously incorporated into systems for producing hydrogen for PEM fuel cells.

Abstract: A composition for abatement of airborne pollution by volatile organic compounds (“VOCs”) has an upstream composition which contains a protective adsorbent, e.g., Y zeolite, which is effective for adsorbing large VOC molecules, e.g., toluene, and a protective oxidation catalyst intimately intermingled therewith. The downstream composition contains a second adsorbent, e.g., a silver-containing ZSM-5, which is effective for adsorbing relatively smaller VOC molecules, e.g., propylene, and a second oxidation catalyst intimately intermingled therewith. Oxidation of VOCs while they are still retained on the adsorbents is promoted at temperatures lower than would be required if the VOCs were desorbed into the gaseous phase. Apparatus is provided including a first contact member (24) coated with the upstream composition and positioned upstream of a second contact member (32) coated with the downstream composition.