The present invention discloses a catalyst for in-situ CO2 capture and coupling reduction with biomass oxidation, a preparation method therefor and an application thereof. The catalyst is applied to the coupling reaction of photocatalytic CO2 reduction and biomass oxidation. The preparation of the catalyst is to synthesize layered double hydroxides (LDHs) containing CO32− between layers by using coprecipitation method, hydrothermal method, sol-gel method and the like, wherein the chemical formula is [M1-x2+Mx3+(OH)2]x+(An−)x/n.Math.mH2O, which has a thickness of 20-30 nm and an average particle diameter of 60-90 nm. Then metal ion vacancy defects are produced on LDHs laminate by using a NaOH/KOH selective etching to obtain the corresponding catalyst. The catalyst is used in photocatalytic reaction, characterized in that CO32− is continuously consumed in the reaction process, and the catalyst can absorb CO2 in the air for recovery after the reaction, and can be repeatedly used to continuously consume CO2 in the air, thus realizing the direct capture and effective utilization of CO2.

The invention concerns a process for the preparation of a catalyst for carrying out hydrogenation reactions in hydrotreatment and hydrocracking processes. Said catalyst is prepared from at least one mononuclear precursor based on molybdenum (Mo), in its monomeric or dimeric form, having at least one Mo═O or Mo—OR bond or at least one Mo═S or Mo—SR bond where [R=C.sub.xH.sub.y where x≧1 and (x−1)≦y≦(2x+1) or R=Si(OR′).sub.3 or R=Si(R′).sub.3 where R′=C.sub.x′H.sub.y′ where x′≧1 and (x′−1)≦y′≦(2x′+1)], and optionally from at least one promoter element from group VIII. Said precursors are deposited onto an oxide support which is suitable for the process in which it is used, said catalyst being dried at a temperature of less than 200° C. then advantageously being sulphurized before being deployed in said process.

The object of the present invention is to provide an exhaust gas purifying catalyst that can achieve high purification performance while suppressing H.sub.2S emissions. The object is solved by an exhaust gas purifying catalyst in which the top layer of a catalyst coating layer comprises a ceria-zirconia composite oxide having a pyrochlore-type ordered array structure, in which the ceria-zirconia composite oxide contains at least one additional element selected from the group consisting of praseodymium, lanthanum, and yttrium at 0.5 to 5.0 mol % in relation to the total cation amount, and the molar ratio of (cerium+additional element):(zirconium) is within the range from 43:57 to 48:52.

A process to synthesize a catalyst performing Water-Gas shift reaction at a temperature more than 300° C. using a precursor having general formula [(Cu, Zn).sub.1−x (Al, M).sub.x (OH).sub.2].sup.x+ (A.sup.n−.sub.x/n).kH.sub.2O with M=Al, La, Ga or In, A=CO.sub.3, 0.33<x<0.5, 1<n<3.

The exhaust gas purifying catalyst presented here includes a substrate and a catalyst coat layer formed on the surface of the substrate. The catalyst coat layer is formed in a laminate structure having two layers, with a first layer being nearer to the surface of the substrate and a second layer being relatively further from this surface. The second layer includes a carrier and a noble metal supported on the carrier. The first layer is a noble metal-free layer that does not contain a noble metal but does contain an OSC material having oxygen storage capacity.

The invention concerns a synthesis process of a compound of the following formula (I) or one of the salts thereof,

##STR00001## wherein R represents a COOH, CH.sub.2OH or CHO group, comprising the step according to which the but-3-ene-1,2-diol (BDO) is subjected to an oxidation in the presence of a catalyst, said catalyst comprising an active phase based on at least one noble metal selected from palladium, gold, silver, platinum, rhodium, osmium, ruthenium and iridium, and a support containing alkaline sites.

The invention also concerns the application of this reaction to the preparation of bioavailable compounds of methionine used, in particular, in animal nutrition.

A method for selectively chemically reducing CO.sub.2 to form CO includes providing a catalyst, and contacting H.sub.2 and CO.sub.2 with the catalyst to chemically reduce CO.sub.2 to form CO. The catalyst includes a metal oxide having a chemical formula of Fe.sub.xCo.sub.yMn(.sub.1-x-y)O.sub.z, in which 0.7≤x≤0.95, 0.01≤y≤0.25, and z is an oxidation coordination number.

Disclosed is a process for the preparation of 1,3,3,3-tetrafluoropropene, comprising: (a) a compound having the formula CF.sub.3-xCl.sub.xCHClCHF.sub.2-yCl.sub.y and in the presence of a compound catalyst, undergoes, through n serially-connected reactors, gas-phase fluorination with hydrogen fluoride, producing 1,2,3-trichloro-1,1,3-trifluoropropane, and 1,2-dichloro-1,1,3,3-tetrafluoropropane; in said formula, x=1, 2 or 3; y=1 or 2, and 3≦x+y≦5; (b) 1,2,3-trichloro-1,1,3-trifluoropropane, and 1,2-dichloro-1,1,3,3-tetrafluoropropane undergo, in the presence of a dehalogenation catalyst, gas-phase dehalogenation with hydrogen, producing 3-chloro-1,3,3-trifluoropropene, and 1,1,3,3-tetrafluoropropene; (c) 3-chloro-1,3,3-trifluoropropene and 1,1,3,3-tetrafluoropropene undergo, in the presence of a fluorination catalyst, gas-phase fluorination with hydrogen fluoride, producing 1,3,3,3-tetrafluoropropene. The present invention is primarily used to produce 1,3,3,3-tetrafluoropropene.

Pyrochlore-based solid mixed oxide materials suitable for use in catalysing a hydrocarbon reforming reaction are disclosed, as well as methods of preparing the materials, and their uses in hydrocarbon reforming processes. The materials contain a catalytic quantity of inexpensive nickel and exhibit catalytic properties in dry reforming reactions that are comparable—if not better—than those observed using expensive noble metal-containing catalysts. Moreover, the Pyrochlore-based solid mixed oxide materials can be used in low temperature dry reforming reactions, where other catalysts would become deactivated due to coking. Accordingly, the catalytic materials represent a sizeable development in the industrial-scale reforming of hydrocarbons.

A method of forming a bismuth-based catalyst can include mixing an inorganic alkali compound, a bismuth source compound, a transition metal precursor, and a reducing agent in an aqueous solution to form a bismuth precursor liquid. The bismuth precursor liquid can be hydrothermally reacted at a conversion temperature for a conversion time to produce the bismuth-based catalyst.