The present invention provides a carbon nitride-based photocatalyst and a preparation method thereof. The photocatalyst is prepared by reaction of melem with 3,3,4,4-benzophenonetetracarboxylic dianhydride. The photocatalyst according to an embodiment of the present invention achieves energy level matching in structure between the melem structure and the 3,3,4,4-benzophenonetetracarboxylic dianhydride, reduces a singlet-triplet energy gap (E.sub.ST), promotes an intersystem crossing process, thereby enhancing the singlet oxygen production and improving the selective photocatalytic oxidation ability.

The subject invention pertains to a method of halogenating phenols, yielding a range of halogenated phenols with enantiomeric ratio of up to 99.5:0.5. In certain embodiments, the subject invention pertains to a method of asymmetric halogenation of bisphenol, yielding a range of chiral bisphenol ligands. The novel chiral bisphenols are potent privileged catalyst cores that can be applied to the preparation of ligands for various catalytic asymmetric reactions. The catalyst library can easily be accessed because late-stage modification of the scaffold can readily be executed through cross-coupling of the halogen handles on the bisphenols.

Proposed is a catalyst system specifically for the rearrangement of epoxides into allyl alcohols comprising or consisting of (a) a salt of formula (I) XY (I) in which X represents Zn.sup.2+ and/or Co.sup.2+ and Y represents an anion selected from the group formed from laurate, palmitate, stearate, picolinate, glycinate, gluconate, naphthenate, 2-hexyldecanoate, 2-octyldodecanoate, cyclohexane butyrate and mixtures thereof, and (b) at least one aminophenol.

A process for the selective hydrogenation of polyunsaturated compounds containing at least 2 carbon atoms per molecule, contained in a hydrocarbon feedstock having a final boiling point below or equal to 300 C. in the presence of a catalyst comprising an alumina support and an active phase comprising nickel, said active phase not comprising a metal from Group VIB, said catalyst being prepared by a process comprising at least: i) a step of bringing said support into contact with at least one solution containing at least one nickel precursor; ii) a step of bringing said support into contact with at least one solution containing at least one organic compound comprising at least one carboxylic acid function; iii) a step of drying said impregnated support at a temperature below 250 C.;
steps i) and ii) being carried out separately, in any order.

A hydroprocessing catalyst or catalyst precursor has been developed. The catalyst is a unique transition metal tungsten oxy-hydroxide material. The hydroprocessing using the transition metal tungsten oxy-hydroxide material or the decomposition product thereof may include hydrodenitrification, hydrodesulfurization, hydrodemetallation, hydrodesilication, hydrodearomatization, hydroisomerization, hydrotreating, hydrofining, and hydrocracking.

The invention has as its object a catalyst that comprises a substrate based on alumina or silica or silica-alumina, at least one element from group VIII, at least one element from group VIB, and at least one additive that is selected from among 2-acetylbutyrolactone and/or its hydrolysis products, 2-(2-hydroxyethyl)-3-oxobutanoic acid, and 3-hydroxy-2-(2-hydroxyethyl)-2-butenoic acid. The invention also relates to the method for preparation of said catalyst and its use in a method for hydrotreatment and/or hydrocracking.

The subject invention pertains to a method of halogenating phenols, yielding a range of halogenated phenols with enantiomeric ratio of up to 99.5:0.5. In certain embodiments, the subject invention pertains to a method of asymmetric halogenation of bisphenol, yielding a range of chiral bisphenol ligands. The novel chiral bisphenols are potent privileged catalyst cores that can be applied to the preparation of ligands for various catalytic asymmetric reactions. The catalyst library can easily be accessed because late-stage modification of the scaffold can readily be executed through cross-coupling of the halogen handles on the bisphenols.

The invention has as its object a catalyst that comprises a substrate based on alumina or silica or silica-alumina, at least one element from group VIII, at least one element from group VIB, and an organic compound of formula (I)

##STR00001##

in which R1, R2, R3, R4 and R5 are selected from among a hydrogen atom, or a hydroxyl radical, or a hydrocarbon radical that comprises from 1 to 12 carbon atoms that can also comprise at least one oxygen atom, and R6 is selected from a hydrogen atom, a hydrocarbon radical that comprises from 1 to 12 carbon atoms that can also comprise at least one oxygen atom, a methacryloyl radical, an acryloyl radical or an acetyl radical. The invention also relates to the method for preparation of said catalyst and its use in a method for hydrotreatment and/or hydrocracking.

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.

A redox composition includes a carbohydrate material and a catalytic molar amount of an organic compound positioned in catalytic relationship with the carbohydrate material to catalyze oxidation of the carbohydrate material in an environment in which the carbohydrate material would not otherwise oxidize.