An endothermic catalytic dehydrogenation process conducted in gas phase in system including a reactor with a catalyst bed including an inorganic catalytic material and a first inert material including the steps of: feeding a first stream having an alkane of the formulae I C.sub.nH.sub.2n+1R.sup.1 with n?3 and R.sup.1?H or aryl to be dehydrogenated into the reactor, and simultaneously or subsequently feeding a second stream including a mixture of an inert gas and a reactive gas selected from the group of alkanes of the formulae II C.sub.mH.sub.2m+2 with m?2, or alkenes of the formulae III C.sub.mH.sub.2m with .sub.m?2. The alkane to be dehydrogenated of formulae I in first stream has at least one more carbon atom than the alkane of formulae II and alkene of formulae III in the second stream.

A molecular sieve having the framework structure of ZSM-5 is described comprising crystals having an external surface area in excess of 100 m.sup.2/g (as determined by the t-plot method for nitrogen physisorption) and a unique X-ray diffraction pattern.

A molecular sieve having the framework structure of ZSM-5 is described comprising crystals having an external surface area in excess of 100 m.sup.2/g (as determined by the t-plot method for nitrogen physisorption) and a unique X-ray diffraction pattern.

Disclosed herein are processes for tandem alkene dehydrogenation/alkene dimerization using an iridium pincer complex catalyst on a support comprising magnesium silicates (e.g., Florisil). The reaction process comprises providing an iridium pincer complex bound to a solid support comprising magnesium silicates; providing a gaseous alkane feedstock comprising at least one alkane; and contacting the gaseous alkane feedstock with the iridium pincer complex bound to the solid support in the presence of a hydrogen acceptor to form dimerized alkenes. The processes disclosed herein can accomplish facile, low-temperature tandem transfer dehydrogenation of alkanes and dimerization of alkenes with unprecedented TONs at a reasonable rate of conversion.

Disclosed herein are processes for tandem alkene dehydrogenation/alkene dimerization using an iridium pincer complex catalyst on a support comprising magnesium silicates (e.g., Florisil). The reaction process comprises providing an iridium pincer complex bound to a solid support comprising magnesium silicates; providing a gaseous alkane feedstock comprising at least one alkane; and contacting the gaseous alkane feedstock with the iridium pincer complex bound to the solid support in the presence of a hydrogen acceptor to form dimerized alkenes. The processes disclosed herein can accomplish facile, low-temperature tandem transfer dehydrogenation of alkanes and dimerization of alkenes with unprecedented TONs at a reasonable rate of conversion.

Described herein are methods useful for preparing alkylaromatics.

Described herein are methods useful for preparing alkylaromatics.

The object of the invention is to specify a process for dehydrogenating alkanes in which such feedstock mixtures may be used having a high proportion of olefins, i.e. approximately 1% by weight to 10% by weight. Specifically, alkenes having two to five carbon atoms should be generated from alkanes having the same chain length and therefore the number of carbon atoms should not be changed by the dehydrogenation. The process is intended to be feasible on an industrial scale. A basic concept of the invention consists of hydrogenating alkenes present in the feedstock mixture to the corresponding alkanes before they come into contact with the dehydrogenation catalyst. An undesired coke deposit is thus avoided. The hydrogenation is effected by minimal addition of hydrogen (80% to 120% of the stoichiometrically required amount). The hydrogenation is effected either over a hydrogenation catalyst specifically provided therefor, which differs from the dehydrogenation catalyst, or over the dehydrogenation catalyst itself.

The object of the invention is to specify a process for dehydrogenating alkanes in which such feedstock mixtures may be used having a high proportion of olefins, i.e. approximately 1% by weight to 10% by weight. Specifically, alkenes having two to five carbon atoms should be generated from alkanes having the same chain length and therefore the number of carbon atoms should not be changed by the dehydrogenation. The process is intended to be feasible on an industrial scale. A basic concept of the invention consists of hydrogenating alkenes present in the feedstock mixture to the corresponding alkanes before they come into contact with the dehydrogenation catalyst. An undesired coke deposit is thus avoided. The hydrogenation is effected by minimal addition of hydrogen (80% to 120% of the stoichiometrically required amount). The hydrogenation is effected either over a hydrogenation catalyst specifically provided therefor, which differs from the dehydrogenation catalyst, or over the dehydrogenation catalyst itself.

Disclosed herein are processes for tandem alkene dehydrogenation/alkene dimerization using an iridium pincer complex catalyst on a support comprising magnesium silicates (e.g., Florisil). The reaction process comprises providing an iridium pincer complex bound to a solid support comprising magnesium silicates; providing a gaseous alkane feedstock comprising at least one alkane; and contacting the gaseous alkane feedstock with the iridium pincer complex bound to the solid support in the presence of a hydrogen acceptor to form dimerized alkenes. The processes disclosed herein can accomplish facile, low-temperature tandem transfer dehydrogenation of alkanes and dimerization of alkenes with unprecedented TONs at a reasonable rate of conversion.