A process for steam reforming a hydrocarbon feedstock containing one or more nitrogen compounds, including passing a mixture of the hydrocarbon feedstock and steam through a catalyst bed of one or more nickel steam reforming catalysts disposed within a plurality of externally heated tubes in a tubular steam reformer, each tube having an inlet to which the mixture of hydrocarbon and steam is fed, an outlet from which a reformed gas containing hydrogen, carbon monoxide, carbon dioxide, steam, ammonia and methane is recovered. The steam reforming catalyst at least at the outlet of the tubes comprises nickel dispersed over a porous metal oxide surface present as a coating on a non-porous metal or ceramic structure. The nickel content of the metal oxide coating is in the range of 5 to 50% by weight and the thickness of the coating is in the range of 5 to 150 micrometres.

The present invention disclosed an improved process for the preparation of bimetallic core-shell nanoparticles by using facile aqueous phase synthesis strategy and their application in catalysis such as selective hydrogenation of alkynes into alkenes or alkanes and CO hydrogenation to hydrocarbons.

Aspects described herein generally relate to bimetallic structures, syntheses thereof, and uses thereof. In an embodiment, a process for forming a bimetallic nanoframe is provided. The process includes forming a first bimetallic structure by reacting a first precursor comprising platinum (Pt) and a second precursor comprising a Group 8-11 metal (M.sup.2), wherein M.sup.2 is free of Pt; reacting a third precursor comprising Pt with the first bimetallic structure to form a second bimetallic structure, the second bimetallic structure having a higher molar ratio of Pt to Group 8-11 metal than the first bimetallic structure; and introducing the second bimetallic structure with an acid to form the bimetallic nanoframe, the bimetallic nanoframe having a higher molar ratio of Pt to Group 8-11 metal than that of the second bimetallic structure, the bimetallic nanoframe having the formula: (Pt).sub.a(M.sup.2).sub.b, wherein: a is the amount of Pt; b is the amount of M.sup.2.

A catalyst in a calcined state has a specific surface area of 20-50 m.sup.2/g of catalyst, and a specific surface area of nickel metal after reduction of the catalyst of 8 to 11 m.sup.2/g, wherein the average particle size of nickel metal is 3-8 nm, the dispersion of the particles is 10-16%, and the content of nickel is 5-15 wt. % based on the weight of calcined catalyst. A support has a specific surface area of 40-120 m.sup.2/g with a pore volume of the support of 0.2-0.4 cm.sup.3/g, wherein the support is selected from a mixture of zirconium oxide and cerium oxide or magnesium oxide, cerium oxide and the ballast being zirconium oxide. The catalyst further contains a promoter selected from the group consisting of palladium and ruthenium, in an amount of from 0.01 to 0.5 wt. %. The catalyst is prepared by co-precipitation with ammonium hydroxide from a solution containing nickel, cerium and zirconium precursors and distilled water or from a solution containing nickel, cerium, zirconium, and magnesium precursors and distilled water, and having a pH of 8.0-9.0. The process is carried out under agitation at a temperature of 40-45° C. for 1-2 hours, followed by filtration, drying at a temperature of 100-110° C. for 6-8 hours, and calcining at a temperature of 400-650° C. for 4-6 hours. The invention provides a high average conversion of natural/associated gas of at least 90% in an autothermal reforming reaction of natural or associated gas, and a high synthesis gas output of at least 7000 m.sup.3/m.sup.3.sub.cat.Math.h.

Disclosed are a perovskite compound, a method for producing the perovskite compound, a catalyst for a fuel cell including the perovskite compound, and a method for producing the catalyst. The perovskite compound overcomes the low stability of palladium due to its perovskite structural properties. Therefore, the perovskite compound can be used as a catalyst material for a fuel cell. In addition, the use of palladium in the catalyst instead of expensive platinum leads to an improvement in the price competitiveness of fuel cells. The catalyst is highly durable and catalytically active due to its perovskite structure.

A catalyst comprising a noble metal disposed on a support. The noble metal is present in an amount ranging from 0.1 wt % to 10 wt % relative to the total weight of the catalyst. The support comprises at least 50 wt % silicon carbide relative to the total weight of the support. The silicon carbide has a surface area of at least 5 m.sup.2/g. A method for preparing methyl methacrylate from methacrolein and methanol using the catalyst is also disclosed.

Embodiments of the present invention relates to two improved catalysts and associated processes that directly converts carbon dioxide and hydrogen to liquid fuels. The catalytic converter is comprised of two catalysts in series that are operated at the same pressures to directly produce synthetic liquid fuels or synthetic natural gas. The carbon conversion efficiency for CO.sub.2 to liquid fuels is greater than 45%. The fuel is distilled into a premium diesel fuels (approximately 70 volume %) and naphtha (approximately 30 volume %) which are used directly as “drop-in” fuels without requiring any further processing. Any light hydrocarbons that are present with the carbon dioxide are also converted directly to fuels. This process is directly applicable to the conversion of CO.sub.2 collected from ethanol plants, cement plants, power plants, biogas, carbon dioxide/hydrocarbon mixtures from secondary oil recovery, and other carbon dioxide/hydrocarbon streams. The catalyst system is durable, efficient and maintains a relatively constant level of fuel productivity over long periods of time without requiring re-activation or replacement.

A catalyst for production of carboxylic acid ester, containing: catalyst particles containing at least one element selected from the group consisting of nickel, cobalt, palladium, lead, platinum, ruthenium, gold, silver, and copper; and a support supporting the catalyst particles, wherein the catalyst for production of carboxylic acid ester has half-width Wa of pore distribution of 10 nm or less, the half-width Wa being calculated using BJH method from an adsorption isotherm obtained by nitrogen adsorption.

Aspects described herein generally relate to bimetallic structures, syntheses thereof, and uses thereof. In an embodiment, a process for forming a bimetallic nanoframe is provided. The process includes forming a first bimetallic structure by reacting a first precursor comprising platinum (Pt) and a second precursor comprising a Group 8-11 metal (M.sup.2), wherein M.sup.2 is free of Pt; reacting a third precursor comprising Pt with the first bimetallic structure to form a second bimetallic structure, the second bimetallic structure having a higher molar ratio of Pt to Group 8-11 metal than the first bimetallic structure; and introducing the second bimetallic structure with an acid to form the bimetallic nanoframe, the bimetallic nanoframe having a higher molar ratio of Pt to Group 8-11 metal than that of the second bimetallic structure, the bimetallic nanoframe having the formula: (Pt).sub.a(M.sup.2).sub.b, wherein: a is the amount of Pt; b is the amount of M.sup.2.

Methods for preparing ceria-zirconia (CZO) materials calcined with precious group metals (PGM) include calcining a CZO material with PGM. The calcined CZO/PGM catalyst is reduced at a temperature of ≥1000° C. to ≤1100° C. for a time of ≥0.5 hour to 1 hour to form a (CZO/PGM)-pyrochlore catalyst. The (CZO/PGM)-pyrochlore catalyst exhibits superior oxygen storage capacity characteristics as a three-way catalyst in vehicle exhaust gas systems.