The present invention concerns a multifunctional catalyst for the conversion of CO.sub.2 into useful products, such as CO via the reverse water gas shift reaction. The catalyst according to the invention efficiently combined a water sorption functionality with at least one catalytic functionality into a single particle, by having a solid water sorbent impregnated with at least one metal capable of converting CO.sub.2 from a gaseous mixture comprising H.sub.2 and CO.sub.2. The catalyst according to the invention allows for higher selectivity in the conversion of CO.sub.2, at more lenient conditions in terms of temperature and pressure, and improved stability of the catalyst itself. The invention also concerns a process for converting CO.sub.2, utilizing the catalyst and the use of the catalyst in the conversion of CO.sub.2.

This invention describes methods of alkylating isobutane which include a catalytic reaction system comprising a crystalline zeolite catalyst and a rare earth-modified molecular sieve adsorbent (RE—MSA). The crystalline zeolite catalyst comprises sodalite cages and supercages, a Si/Al molar ratio of 20 or less, less than 0.5 weight percent alkali metals; and up to 5 wt% of Pt, Pd and or Ni, and acid-site density (including both Lewis and Brønsted acid sites) of at least 100 .Math.mole/gm. The RE-modified molecular sieve adsorbent (Re—MSA) comprising sodalite cages and supercages, a Si/Al molar ratio of 20 or less, less than 1 wt% of alkali metals, RE (rare earth elements) in the range of 10 to 30 wt% and transition metals selected from groups 9-11 in the range from 2 wt% to 10 wt; and acid-site density of no more than 30 .Math.mole/gm. The invention also includes methods of making RE—MSA.

Improved alkylation catalysts, alkylation methods, and methods of making alkylation catalysts are described. The alkylation method comprises reaction over a solid acid, zeolite-based catalyst and can be conducted for relatively long periods at steady state conditions. The alkylation catalyst comprises a crystalline zeolite structure, a Si/Al molar ratio of 20 or less, less than 0.5 weight percent alkali metals, and further having a characteristic catalyst life property. Some catalysts may contain rare earth elements in the range of 10 to 35 wt %. One method of making a catalyst includes a calcination step following exchange of the rare earth element(s) conducted at a temperature of at least 575° C. to stabilize the resulting structure followed by an deammoniation treatment. An improved method of deammoniation uses low temperature oxidation.

This invention relates to process for producing biphenyl esters, the process comprising: (a) contacting a feed comprising toluene, xylene or mixtures thereof with hydrogen in the presence of a hydroalkylation catalyst to produce a hydroalkylation reaction product comprising (methylcyclohexyl)toluene, wherein the hydroalkylation catalyst comprises: 1) binder present at 40 wt % or less (based upon weight of final catalyst composition), 2) a hydrogenation component present at 0.2 wt % or less (based upon weight of final catalyst composition), and 3) an acidic component comprising a molecular sieve having a twelve membered (or larger) ring pore opening, channel or pocket and a largest pore dimension of 6.0 angstroms or more present at 60 wt % or more, (based upon weight of final catalyst composition); (b) dehydrogenating the hydroalkylation reaction product using a dehydrogenation catalyst to produce a dehydrogenation reaction product comprising a mixture of methyl-substituted biphenyl compounds; (c) contacting at the dehydrogenation reaction product with an oxidizing gas to convert the methyl-substituted biphenyl compounds to biphenyl carboxylic acids; and (d) reacting the biphenyl carboxylic acids with one or more C.sub.1 to C.sub.14 alcohols to produce biphenyl esters.

Disclosed are processes for conversion of a feedstock comprising C.sub.8+ aromatic hydrocarbons to lighter aromatic products in which the feedstock and optionally hydrogen are contacted in the presence of the catalyst composition under conversion conditions effective to dealkylate and transalkylate said C.sub.8+ aromatic hydrocarbons to produce said lighter aromatic products comprising benzene, toluene and xylene. The catalyst composition comprises a zeolite, a first metal, and a second metal, and is treated with a source of sulfur and/or a source of steam.

The present invention relates to a catalyst for isomerization of alkylated aromatics such as mixed xylenes, using xylene isomerization catalyst particles including post-framework modified *BEA zeolite in which zirconium atoms and/or hafnium atoms, optionally in combination with titanium atoms, form a part of a framework of a beta-type zeolite.

The present invention relates to a catalyst for isomerization of alkylated aromatics such as mixed xylenes, using xylene isomerization catalyst particles including post-framework modified USY zeolite in which zirconium atoms and/or titanium atoms and/or hafnium atoms form a part of a framework of an ultra-stable Y-type zeolite.

Improved alkylation catalysts, alkylation methods, and methods of making alkylation catalysts are described. The alkylation method comprises reaction over a solid acid, zeolite-based catalyst and can be conducted for relatively long periods at steady state conditions. The alkylation catalyst comprises a crystalline zeolite structure, a Si/Al molar ratio of 20 or less, less than 0.5 weight percent alkali metals, and further having a characteristic catalyst life property. Some catalysts may contain rare earth elements in the range of 10 to 35 wt %. One method of making a catalyst includes a calcination step following exchange of the rare earth element(s) conducted at a temperature of at least 575° C. to stabilize the resulting structure followed by an deammoniation treatment. An improved method of deammoniation uses low temperature oxidation.

The present invention relates to a catalyst for isomerization of alkylated aromatics such as mixed xylenes, using xylene isomerization catalyst particles including post-framework modified USY zeolite in which zirconium atoms and/or titanium atoms and/or hafnium atoms form a part of a framework of an ultra-stable Y-type zeolite.

A solid acid catalyst has a macropore specific volume of about 0.30-0.50 ml/g, a ratio of macropore specific volume to specific length of catalyst particles of about 1.0-2.5 ml/(g.Math.mm), and a ratio of specific surface area to length of catalyst particles of about 3.40-4.50 m.sup.2/mm. The macropore refers to pores having a diameter of more than 50 nm. An alkylation catalyst is based on the solid acid catalyst and can be used in alkylation reactions. The solid acid catalyst and alkylation catalyst show an improved catalyst service life and/or trimethylpentane selectivity when used in the alkylation of isoparaffins with olefins.