The disclosure relates to a single-atom-based catalyst system with total-length control of single-atom catalytic sites. The single-atom-based catalyst system comprises at least one catalyst structure comprising a first assembly of a plurality of single-atom-catalyst superparticles. The single-atom-catalyst superparticles comprise a second assembly of a plurality of single-atom-catalyst nanoparticles. The single-atom-based catalyst system has controlled porosity and spatial distribution of active single-atom catalysts from the atomic scale to the macroscopic scale. This abstract is intended as a scanning tool for purposes of searching in the particular art and is not intended to be limiting of the present disclosure.

A process for preparing a silver-containing catalyst for the selective oxidation of ethylene to ethylene oxide including the steps of: (a) providing a multimodal support, (b) preparing an impregnation solution comprising a silver component, (c) impregnating, at least once, the multimodal support of step (a) with the silver-containing impregnation solution of step (b) to form an impregnated support; (d) subjecting the impregnated multimodal support from step (c) to a removal means, such as a centrifuge, at least once, for a time sufficient to remove impregnated silver impregnation solution from the multimodal support and to control the amount of silver in the pores of the multimodal support by selectively removing impregnated silver impregnation solution from a set of larger pores in the multimodal support; (e) roasting, at least once, the multimodal support after the step (d); (f) optionally, repeating the impregnation step (c), (g) optionally, repeating the centrifugation step (d), and (h) optionally, repeating the calcination step (e).

A process for preparing a silver-containing catalyst for the selective oxidation of ethylene to ethylene oxide including the steps of: (a) providing a multimodal support, (b) preparing an impregnation solution comprising a silver component, (c) impregnating, at least once, the multimodal support of step (a) with the silver-containing impregnation solution of step (b) to form an impregnated support; (d) subjecting the impregnated multimodal support from step (c) to a removal means, such as a centrifuge, at least once, for a time sufficient to remove impregnated silver impregnation solution from the multimodal support and to control the amount of silver in the pores of the multimodal support by selectively removing impregnated silver impregnation solution from a set of larger pores in the multimodal support; (e) roasting, at least once, the multimodal support after the step (d); (f) optionally, repeating the impregnation step (c), (g) optionally, repeating the centrifugation step (d), and (h) optionally, repeating the calcination step (e).

A method for activating a chromia-based catalyst for fluorination and/or hydrofluorination comprises the steps of: a) optionally drying the catalyst at a temperature of from 100° C. to 400° C.; b) treating the catalyst with a composition comprising HF at a temperature of from 100° C. to about 500° C.; c) treating the catalyst with a composition comprising an oxidant and optionally HF at a temperature of from about 100° C. to about 500° C.

A method for activating a chromia-based catalyst for fluorination and/or hydrofluorination comprises the steps of: a) optionally drying the catalyst at a temperature of from 100° C. to 400° C.; b) treating the catalyst with a composition comprising HF at a temperature of from 100° C. to about 500° C.; c) treating the catalyst with a composition comprising an oxidant and optionally HF at a temperature of from about 100° C. to about 500° C.

The present invention relates to a selective catalytic reduction catalyst for the treatment of an exhaust gas of a diesel engine comprising (i) a flow-through substrate comprising an inlet end, an outlet end, a substrate axial length extending from the inlet end to the outlet end and a plurality of passages defined by internal walls of the flow-through substrate extending therethrough; (II) a coating disposed on the surface of the internal walls of the substrate, where-in the surface defines the interface between the passages and the internal walls, wherein the coating comprises a vanadium oxide supported on an oxidic material comprising titania, and further comprises a mixed oxide of vanadium and one or more of iron, erbium, bismuth, cerium, europium, gadolinium, holmium, lanthanum, lutetium, neodymium, praseodymium, promethium, samarium, scandium, terbium, thulium, ytterbium, yttrium, molybdenum, tungsten, manganese, cobalt, nickel, copper, aluminum and antimony.

The present invention relates to a carbon-based precious metal-transition metal composite catalyst and a preparation method therefor, and more particularly, to a catalyst synthesis method in which, when preparing a high-content precious metal-transition metal composite catalyst, a catalyst having uniform particles and composition can be prepared, and cyclohexane dimethanol (CHDM) is efficiently produced by the hydrogenation reaction of cyclohexane dicarboxylic acid (CHDA) in an aqueous solution. Provided is a method for preparing a carbon-based precious metal-transition metal composite catalyst, wherein, in the carbon-based precious metal-transition metal composite catalyst, the precious metal is included in an amount of 10-20 parts by weight, and the transition metal is included in an amount of 10-20 parts by weight based on 100 parts by weight of the composite catalyst, and thus a total amount of the precious metal-transition metal is 20-40 parts by weight based on 100 parts by weight of the composite catalyst.

A method of manufacturing a catalyst material includes the steps of: providing a body having an open-porous foam structure and comprising at least a first metal or alloy; providing particles, each of which particles comprising at least a second metal or alloy; distributing the particles on the body; forming a structural connection between each of at least a subset of the particles and the body; and forming an oxide film on at least the subset of the particles and the body, wherein the oxide film has a catalytically active surface.

A catalyst for the carbonylation of dimethyl ether to methyl acetate. The catalyst comprises a zeolite, such as a mordenite zeolite, at least one Group IB metal, such as copper, and/or at least one Group VIII metal, such as iron, and at least one Group IIB metal, such as zinc. Such a catalyst with combined metals provides enhanced catalytic activity, improved stability, and improved selectivity to methyl acetate, and does not require a halogen promoter, as compared to a metal-free or copper only zeolite.

A catalyst for the carbonylation of dimethyl ether to methyl acetate. The catalyst comprises a zeolite, such as a mordenite zeolite, at least one Group IB metal, such as copper, and/or at least one Group VIII metal, such as iron, and at least one Group IIB metal, such as zinc. Such a catalyst with combined metals provides enhanced catalytic activity, improved stability, and improved selectivity to methyl acetate, and does not require a halogen promoter, as compared to a metal-free or copper only zeolite.