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.

A method of converting nitrogen oxides in a gas to nitrogen by contacting the nitrogen oxides with a nitrogenous reducing agent in the presence of a zeolite catalyst containing at least one transition metal, wherein the zeolite is a small pore zeolite containing a maximum ring size of eight tetrahedral atoms, wherein the at least one transition metal is selected from the group consisting of Cr, Mn, Fe, Co, Ce, Ni, Cu, Zn, Ga, Mo, Ru, Rh, Pd, Ag, In, Sn, Re, Ir and Pt.

Methods for cracking a hydrocarbon feed stream include contacting a hydrocarbon feed stream with a catalyst system in a catalytic cracking unit having a flowing gas stream to obtain a cracking product containing light olefins. The catalyst system includes at least a base catalyst. The base catalyst includes a pentasil zeolite. The pentasil zeolite includes from 0.01% to 5% by mass lithium atoms, as calculated on an oxide basis, based on the total mass of the pentasil zeolite. The flowing gas stream comprises hydrogen and, optionally, at least one additional carrier gas.

A fibrous hierarchical zeolite includes a framework comprising aluminum atoms, silicon atoms, and oxygen atoms, the framework further comprising a plurality of micropores and a plurality of mesopores. The framework comprises no Brønsted acid activity.

A method for preparing a core-shell structure photocatalytic material includes: obtaining a titanyl sulfate solution by mixing and reacting sulfuric acid and metatitanic acid; obtaining a mixed solution by adding a porous material having a hydrophilic surface into the titanyl sulfate solution; adding an alkali into the mixed solution to obtain a precipitation product by reacting the alkali with the titanyl sulfate coated on the surface of the porous material; and filtering, washing, drying and calcining the precipitation product to obtaining a core-shell structure photocatalytic material with the porous material as a core and a mesoporous quantum titanium oxide as a shell.

A method for preparing a core-shell structure photocatalytic material includes: obtaining a titanyl sulfate solution by mixing and reacting sulfuric acid and metatitanic acid; obtaining a mixed solution by adding a porous material having a hydrophilic surface into the titanyl sulfate solution; adding an alkali into the mixed solution to obtain a precipitation product by reacting the alkali with the titanyl sulfate coated on the surface of the porous material; and filtering, washing, drying and calcining the precipitation product to obtaining a core-shell structure photocatalytic material with the porous material as a core and a mesoporous quantum titanium oxide as a shell.

Provided herein is a catalytic article including a catalytic coating disposed on a substrate, wherein the catalytic coating comprises a bottom coating on the substrate and a top coating layer on the bottom coating layer, one such coating layer containing a platinum group metal on a refractory metal oxide support and the other such coating layer containing a ceria-containing molecular sieve. Such catalytic articles are effective toward treating exhaust gas streams of internal combustion engines and exhibit outstanding resistance to sulfur.

Disclosed are catalysts comprised of platinum and gold. The catalysts are generally useful for the selective oxidation of compositions comprised of a primary alcohol group and at least one secondary alcohol group wherein at least the primary alcohol group is converted to a carboxyl group. More particularly, the catalysts are supported catalysts including particles comprising gold and particles comprising platinum, wherein the molar ratio of platinum to gold is in the range of about 100:1 to about 1:4, the platinum is essentially present as Pt(0) and the platinum-containing particles are of a size in the range of about 2 to about 50 nm. Also disclosed are methods for the oxidative chemocatalytic conversion of carbohydrates to carboxylic acids or derivatives thereof. Additionally, methods are disclosed for the selective oxidation of glucose to glucaric acid or derivatives thereof using catalysts comprising platinum and gold. Further, methods are disclosed for the production of such catalysts.

Disclosed are catalysts comprised of platinum and gold. The catalysts are generally useful for the selective oxidation of compositions comprised of a primary alcohol group and at least one secondary alcohol group wherein at least the primary alcohol group is converted to a carboxyl group. More particularly, the catalysts are supported catalysts including particles comprising gold and particles comprising platinum, wherein the molar ratio of platinum to gold is in the range of about 100:1 to about 1:4, the platinum is essentially present as Pt(0) and the platinum-containing particles are of a size in the range of about 2 to about 50 nm. Also disclosed are methods for the oxidative chemocatalytic conversion of carbohydrates to carboxylic acids or derivatives thereof. Additionally, methods are disclosed for the selective oxidation of glucose to glucaric acid or derivatives thereof using catalysts comprising platinum and gold. Further, methods are disclosed for the production of such catalysts.

Disclosed in the present invention is a tail gas treatment catalyst. The catalyst consists of a carrier, a first catalyst, and a second catalyst. The first catalyst and the second catalyst are provided on both ends of the carrier. The first catalyst can purify pollutants in tail gas. The second catalyst can purify a byproduct, ammonia, obtained by the purification by the first catalyst and pollutants that are not completely purified by the first catalyst. The second catalyst is of a double-layer structure; the lower layer consists of an oxygen storage material, aluminum oxide, and a second active component; the second active component is a composition of Pt and Pd, or a composition of Ce, Fe, Ni and Cu; the upper layer consists of a molecular sieve and a third active component; the third active component is Cu or a composition of Cu and Fe. The tail gas treatment catalyst of the present invention has high purification treatment efficiency, and can significantly reduce the emissions of CH.sub.4, CO, and NO.sub.x in the tail gas, especially reduce the content of the byproduct, NH.sub.3, so that the tail gas can meet China VI emission standards.