A formic acid decomposition catalyst system includes metal-ligand complexes having formula 1: ##STR00001##
wherein M is a transition metal; R.sub.1, R.sub.2 are independently C.sub.1-6 alkyl groups; o is 1, 2, 3, or 4; R.sub.3 are independently hydrogen, C.sub.1-6 alkyl groups, OR.sub.14, NO.sub.2, or halogen; R.sub.4, R.sub.5, R.sub.6, R.sub.7, R.sub.8, R.sub.9, R.sub.10, R.sub.11, R.sub.12, R.sub.13, are independently hydrogen or C.sub.1-6 alkyl groups; R.sub.14 is a C.sub.1-6 alkyl group; and X.sup. is a negatively charge counter ion.

The present invention relates to a method for producing hydrogen, in which hydrogen is generated from a formate using a metal catalyst in the presence of a solvent by a two-phase system reaction in which the solvent is present in a state where an organic phase and an aqueous phase are separated.

A process is presented for the management of sulfur on a catalyst. The catalyst is a dehydrogenation catalyst, and sulfur accumulates during the dehydrogenation process. Sulfur compounds are stripped from the spent catalyst and the catalyst is cooled before the regeneration process. The process includes controlling the amount of sulfur that needs to be removed from the catalyst before regeneration.

A process is presented for the management of sulfur on a catalyst. The catalyst is a dehydrogenation catalyst, and sulfur accumulates during the dehydrogenation process. Sulfur compounds are stripped from the spent catalyst and the catalyst is cooled before the regeneration process. The process includes controlling the amount of sulfur that needs to be removed from the catalyst before regeneration.

A heterogeneous catalyst comprising a metal-containing polymer matrix covalently bonded to a support material and a method of making and using such catalysts. The metal-containing polymer matrix comprises metal nano-particles encapsulated in a polymer matrix, e.g., a siloxane. In one aspect, the metal-containing polymer matrix can be bonded to the support material via a hydrophobic group attached to the support material. The catalyst can be recovered after being used in a metal catalyzed reaction and exhibit excellent catalytic activity upon reuse in subsequent reactions.

The present disclosure provides that a catalyst exhibits excellent catalytic activity in both a hydrogenation involving a hydrogen-storing body containing an aromatic compound, and a dehydrogenation involving a hydrogen-supplying body containing a hydrogen derivative of the aromatic compound, wherein the catalyst contains a nanocrystalline composite having two or more accumulated flake-like nanocrystalline pieces in a connected state, the flake-like nanocrystalline pieces each having a main surface and an end surface, and in that the nanocrystalline composite is configured such that, when two adjacent nanocrystalline pieces are viewed, an end surface of at least one of the nanocrystalline pieces is connected.

The present invention relates to an anti-coking catalyst having a physical property of reducing coke formation, which comprises a solid acid catalyst containing gadolinium (Gd) on the surface, a preparation method thereof, and a use thereof. The preparation method includes a first step of determining the amount of gadolinium (Gd) or a Gd-providing precursor to be used relative to the total weight of the solid acid catalyst, which reduces the coking of a specific solid acid catalyst below a specific level under a specific reaction condition; and a second step of preparing a Gd-containing solid acid catalyst using the amount determined in the first step.

The catalyst according to the present invention is a catalyst in which an appropriate weight ratio of gadolinium is supported on the surface of a pure solid acid substance or solid acid substance on which a specific metal is supported. Therefore, the production of coke on the catalyst surface is inhibited while maintaining the activity of the solid acid catalyst in a hydrocarbon conversion reaction, and as a result, the catalyst of the present invention exhibits an effect of improving its lifespan.

An oxidation catalyst includes a nickel-containing material, a manganese-containing material and a bromine-containing material, wherein the molar number of the element bromine (Br) in the oxidation catalyst to the total molar number of the element nickel (Ni) and the element manganese (Mn) in the oxidation catalyst substantially ranges from 0.01 to 7.5.

Provided is a method for preparing levulinic acid using a solid acid catalyst in the presence of an ethylene glycol-based compound. The levulinic acid according to the present invention can be prepared by using a linear or cyclic ethylene glycol-based compound as a solvent and preparing the levulinic acid from fructose in the presence of the solid acid catalyst at a reaction temperature of 100 to 200 C., thereby reducing the dependency on petroleum in response to greenhouse gas emission regulations. Also, a high yield of levulinic acid can be obtained from fructose, and the solvent and the catalyst can be efficiently separated, collected, and reused after the reaction has completed.

The invention relates to novel metal complexes useful as catalysts in redox reactions (such as, hydrogen (H.sub.2) production). In particular, the invention provides novel transition metal (e.g., cobalt (Co) or nickel (Ni)) complexes, in which the transition metal is coupled with N,N-Bis(2-pyridinylmethyl)-2,2-Bipyridine-6-methanamine (DPA-Bpy), 6-((bis(pyridin-2-ylmethyl)amino)methyl)-N,N-dimethyl-2,2-bipyridin-6-amine (DPA-ABpy), N,N-bis((isoquinolin-1-yl)methyl)(6-(pyridin-2-yl)pyridin-2-yl)methanamine (DIQ-Bpy), or a derivative thereof. The invention also relates to a method of producing H.sub.2 from an aqueous solution by using the metal complex as a catalyst. In certain embodiments, the invention provides a metal complex of the formulae as described herein.