Zeolite catalysts and systems and methods for preparing and using zeolite catalysts having the CHA crystal structure are disclosed. The catalysts can be used to remove nitrogen oxides from a gaseous medium across a broad temperature range and exhibit hydrothermal stable at high reaction temperatures. The zeolite catalysts include a zeolite carrier having a silica to alumina ratio from about 15:1 to about 256:1 and a copper to alumina ratio from about 0.25:1 to about 1:1.

The present invention is directed to the preparation of a cobalt containing catalyst, a precipitate as an intermediate product, a Fischer-Tropsch catalyst and a process for producing normally gaseous, normally liquid and optionally normally solid hydrocarbons from synthesis gas. The precipitate and catalyst comprise crystalline Co(OH)(CO3)0.5, the crystals are needle shaped and have a surface area of at least 80 m.sup.2/g dry precipitate.

Disclosed are a chemochromic nanoparticle, a method for manufacturing the chemochromic nanoparticle, and a hydrogen sensor comprising the chemochromic nanoparticle. In particular, the chemochromic nanoparticle has a core-shell structure such that the chemochromic nanoparticle and comprises a core comprising a hydrated or non-hydrated transition metal oxide; and a shell comprising a transition metal catalyst.

A Fe.sub.43.4Pt.sub.52.3Cu.sub.4.3 heterogeneous phase structure polyhedron nanoparticle, a preparing method and an application as an efficient fuel cell oxygen reduction catalyst are provided. The Fe.sub.43.4Pt.sub.52.3Cu.sub.4.3 heterogeneous phase structure polyhedron nanoparticle, includes: three elements of Fe, Pt and Cu; wherein the Fe.sub.43.4Pt.sub.52.3Cu.sub.4.3 heterogeneous phase structure polyhedron nanoparticle has a heterogeneous phase structure in which face-centered cubic and face-centered tetragonal coexist; wherein the heterogeneous phase structure is a face-centered tetragonal phase shell and face-centered cubic core with a high crystal plane index; a surface of the polyhedron nanoparticle has 1 to 2 atomic layers of enriched with Pt; a diameter distribution of the nanoparticles is at a range of 4.5 to 14.5 nm, and an average size is 8.4 nm. In the invention, hexadecylamine, iron acetylacetonate, copper acetylacetonate, platinum acetylacetonate, and 1,2-hexadecanediol are uniformly mixed, and oleylamine and oleic acid are added, condensed refluxed at 320-330 C.

In some aspects and embodiments, the present application provides a wide range of porous 1-D polymeric graphitic carbon-nitride materials that are atomically doped with binary metals in different morphologies. In some embodiments, the graphitic carbon-nitride materials can be prepared with high mass production from inexpensive and natural abundant precursors. In some embodiments, the materials were used successfully for the oxidation of CO to CO.sub.2 under ambient reaction temperature in addition to the reduction of CO.sub.2 into hydrocarbons. In some embodiments, the materials can be used for practical and large-scale gas conversion for household or industrial applications.

A nitrous oxide (N.sub.2O) removal catalyst composition for treating an exhaust stream of an internal combustion engine is provided, containing a platinum group metal (PGM) component on a metal oxide-based support, wherein the N.sub.2O removal catalyst composition is in a substantially reduced form, such that it has an oxygen deficiency of about 0.05 mmol oxygen atoms/g or greater, and wherein the N.sub.2O removal catalyst composition provides effective removal of at least a portion of N.sub.2O from the exhaust stream under lean conditions at a temperature of about 350 C. or lower. N.sub.2O removal catalytic articles, systems, and methods are also provided for removing at least a portion of N.sub.2O from an exhaust stream under lean, low temperature conditions.

A method for preparing copper-solver and copper-gold porous microsheets with specific pore sizes, the method including the steps of providing a solution of copper microsheets and adding a silver or gold solution under controlled temperature, the reaction conditions can be changed to determine pore sizes.

A multicomponent photocatalyst includes a reactive component optically, electronically, or thermally coupled to a plasmonic material. A method of performing a catalytic reaction includes loading a multicomponent photocatalyst including a reactive component optically, electronically, or thermally coupled to a plasmonic material into a reaction chamber; introducing molecular reactants into the reaction chamber; and illuminating the reaction chamber with a light source.

Disclosed is a process for converting methane into value-added compounds. In this process, a gas mixture containing hydrogen as well as high-concentration acetylene formed through methane pyrolysis (e.g. non-oxidative coupling of methane) is selectively hydrogenated in the presence of a bimetallic supported catalyst. This process obtains ethylene from acetylene in the gas mixture while unreacted methane and hydrogen are recovered as byproducts and/or additionally recycled.

The invention is directed to a CO to CO.sub.2 combustion promoter comprising microsphere sized porous silica and/or alumina comprising particles further comprising on or more Group VIII noble metals wherein the noble metal is distributed in the particle as an eggshell such that a higher content of noble metal is present in the outer region of the particle as compared to the content of noble metal in the center of the particle.