The present invention provides a process for preparing 2,3,3,3-tetrafluoropropene from 1,1,1,2,3-pentachloropropane and/or 1,1,2,2,3-pentachloropropane, comprising the following steps: (a) catalytic reaction of 1,1,1,2,3-pentachloropropane and/or 1,1,2,2,3-pentachloropropane with HF into a reaction mixture comprising HCl, 2-chloro-3,3,3-trifluoropropene, 2,3,3,3-tetrafluoropropene, unreacted HF, and optionally 1,1,1,2,2-pentafluoropropane; (b) separating the reaction mixture into a first stream comprising HCl and 2,3,3,3-tetrafluoropropene and a second stream comprising HF, 2-chloro-3,3,3-trifluoropropene and optionally 1,1,1,2,2-pentafluoropropane; (c) catalytic reaction of the second stream into a reaction mixture comprising 2,3,3,3-tetrafluoropropene, HCl, unreacted 2-chloro-3,3,3-trifluoropropene, unreacted HF and optionally 1,1,1,2,2-pentafluoropropane and (d) feeding the reaction mixture of step (c) directly without separation to step (a).

A method of preparing butadiene that includes supplying butene, oxygen, nitrogen, and steam into a reactor filled with a metal oxide catalyst, and performing an oxidative dehydrogenation reaction at a temperature of 300 to 450 C. as a reaction step; after the reaction step, maintaining supplying the butene, oxygen, nitrogen, and steam within a range within which the flow rate change of the butene, oxygen, nitrogen, and steam is less than 40%, or stopping supplying the butene, and cooling the reactor to a temperature range of 200 C. or lower and higher than 70 C. as a first cooling step; and after the first cooling step, stopping supplying the butene, oxygen, nitrogen, and steam or stopping at least supplying the butene, and cooling the reactor to a temperature of 70 C. or lower as a second cooling step.

The present invention relates to a Cu-based catalyst, a preparation process thereof and its use as the dehydrogenation catalyst in producing a hydroxyketone compound such as acetoin. Said Cu-based catalyst contains copper, at least one auxiliary metal selected from metal of Group IIA, non-noble metal of Group VIII, metal of Group VIB, metal of Group VIIB, metal of Group IIB and lanthanide metal of periodic table of elements, and an alkali metal, and further contains at least one ketone additive selected from a ketone represented by formula (II) and a ketone represented by formula (II). Said Cu-based catalyst shows a high the acetoin selectivity as the dehydrogenation catalyst for producing acetoin.

R1-C(O)CH(OH)R2(II)

R1-C(O)CH(O)R2(II)

In formulae (II) and (II), each group is defined as in the description.

An exhaust purifying apparatus is provided, that can be manufactured at low manufacturing costs and is capable exhibiting high exhaust purifying performance. The exhaust purifying apparatus includes an exhaust passage, and an exhaust purifying member disposed in the exhaust passage. The exhaust purifying member is made of stainless steel. The surface of the stainless steel material is not covered with a catalyst coat containing a catalyst component, so that the surface of the stainless steel material is brought into contact with exhaust. The exhaust purifying member is made of precipitation hardening stainless steel and/or austenitic stainless steel.

A catalyst including between 50.0 and 99.8 percent by weight of iron, between 0 and 5.0 percent by weight of a first additive, between 0 and 10 percent by weight of a second additive, and a carrier. The first additive is ruthenium, platinum, copper, cobalt, zinc, or a metal oxide thereof. The second additive is lanthanum oxide, cerium oxide, magnesium oxide, aluminum oxide, silicon dioxide, potassium oxide, manganese oxide, or zirconium oxide.

A catalyst including between 50.0 and 99.8 percent by weight of iron, between 0 and 5.0 percent by weight of a first additive, between 0 and 10 percent by weight of a second additive, and a carrier. The first additive is ruthenium, platinum, copper, cobalt, zinc, or a metal oxide thereof. The second additive is lanthanum oxide, cerium oxide, magnesium oxide, aluminum oxide, silicon dioxide, potassium oxide, manganese oxide, or zirconium oxide.

The present disclosure discloses a porous ammonia synthesis catalyst, its preparation method and use, which are suitable for catalyzing ammonia synthesis reaction by using nitrogen and hydrogen as raw materials. The porous ammonia synthesis catalyst is a novel ammonia synthesis catalyst material prepared by taking metal coordination compound as template, uniformly dispersing the metal coordination compound in silica gel through a sol-gel method, then carrying out hydrothermal aging, and finally controlling calcination conditions. Compared with traditional synthetic ammonia catalysts, the porous ammonia synthesis catalyst has uniform pore distribution, easily regulated pore size, large specific surface area, easily regulated aggregation degree of metal active centers, particle size, distribution, structure and composition, high ammonia synthesis catalytic efficiency, ammonia synthesis catalysis under mild reaction conditions, high stability, low catalyst preparation cost, which can completely replace existing ammonia synthesis industrial catalysts.

Methods, compositions, and articles of manufacture for alkane activation with single- or bi-metallic catalysts on crystalline mixed oxide supports.

The invention provides a catalyst comprising iron oxide, nickel, ceria or palladium supported on stainless steel foam. The catalyst is effective in oxidising aromatic compounds such as toluene and o-cresol and, advantageously, is particularly effective when the oxidation is carried out at elevated temperatures that correspond to temperatures attained in areas of the aircraft where cabin air is recirculated.

A method is described of producing a catalyst-containing composite oxygen ion membrane and a catalyst-containing composite oxygen ion membrane in which a porous fuel oxidation layer and a dense separation layer and optionally, a porous surface exchange layer are formed on a porous support from mixtures of (Ln.sub.1?xA.sub.x).sub.wCr.sub.1?yB.sub.yO.sub.3?? and a doped zirconia. Adding certain catalyst metals into the fuel oxidation layer not only enhances the initial oxygen flux, but also reduces the degradation rate of the oxygen flux over long-term operation. One of the possible reasons for the improved flux and stability is that the addition of the catalyst metal reduces the chemical reaction between the (Ln.sub.1?xA.sub.x).sub.wCr.sub.1?yB.sub.yO.sub.3?? and the zirconia phases during membrane fabrication and operation, as indicated by the X-ray diffraction results.