This disclosure relates to catalysts comprising gallium, cerium, and a mixed oxide support useful in the dehydrogenation of hydrocarbons, to methods for making such catalysts, and to methods for dehydrogenating hydrocarbons with such catalysts. For example, in one embodiment, a catalyst composition includes gallium oxide, present in the composition in an amount within the range of about 0.1 wt. % to about 30 wt. %, cerium oxide, present in the composition in an amount within the range of about 0.1 wt. % to about 15 wt. %, a promoter, M1, selected from Pt, Ir, La, or a mixture thereof, present in the composition in an amount within the range of about 0.005 wt. % to about 4 wt. %, a promoter, M2, selected from the group 1 elements (e.g., Li, Na, K, Cs), present in the composition in an amount within the range of about 0.05 wt. % to about 3 wt. %, and a support, S1, selected from alumina, silica, zirconia, titania, or a mixture thereof, present in the composition in an amount within the range of about 60 wt. % to about 99 wt. %.

A process of methane catalytic conversion produces olefins, aromatics, and hydrogen under oxygen-free, continuous flowing conditions. Such a process has little coke deposition and realizes atom-economic conversion. Under the conditions encountered in a fixed bed reactor (i.e. reaction temperature: 750-1200 C.; reaction pressure: atmospheric pressure; the weight hourly space velocity of feed gas: 1000-30000 ml/g/h; and fixed bed), conversion of methane is 8-50%. The selectivity of olefins is 30-90%. And selectivity of aromatics is 10-70%. The catalyst for this methane conversion has a SiO.sub.2-based matrix having active species that are formed by confining dopant metal atoms in the lattice of the matrix.

A catalyst for a selective conversion of hydrocarbons. The catalyst includes a first component selected from the group consisting of Group VIII noble metals and mixtures thereof, a second component selected from the group consisting of alkali metals or alkaline-earth metals and mixtures thereof, and a third component selected from the group consisting of tin, germanium, lead, indium, gallium, thallium and mixtures thereof. The catalyst is a support formed as a spherical catalyst particle with an average pore diameter between 200 to 350 Angstroms, a porosity of at least 75% and an apparent bulk density between 0.60 and 0.3 g/cc. Also, a process of using such a catalyst for a selective hydrocarbon conversion reaction and a process for regenerating such a catalyst by removing coke from same.

This disclosure relates to processes, compositions, and systems useful for the oxydehydrogenation of alkanes to form olefins (e.g., for the conversion of ethane to ethylene). The processes use an oxygen transfer agent and may be carried out in any suitable reactor, including a reverse flow reactor, a circulating fluid bed reactor, or a cyclic co-flow reactor.

The present invention relates to a catalytic composition which comprises microspheroidal alumina and an active component containing a mixture comprising Gallium and/or Gallium oxides, Tin and/or Tin oxides, a quantity ranging from 1 ppm to 500 ppm with respect to the total weight of the catalytic composition of platinum and/or platinum oxides, and oxides of alkaline and/or alkaline earth metals.

Processes for dehydrogenation of a hydrocarbon feedstock are described. The process can be run at lower H.sub.2/HC ratios and lower RITs while maintaining coke production at the same level as operation at higher H.sub.2/HC ratios and higher RITs without decreasing the yield per pass. Acceptable levels of coke were achieved when operating the process at low hydrogen to hydrocarbon molar ratio in the range of 0.01 to 0.40 and reactor inlet temperatures in the range of 500-645 C. The process uses a low coke catalyst.

Large pill dehydrogenation catalysts and large screens slot width are combined in dehydrogenation units to reduce the pressure drop across the catalyst bed and reactor screens compared to conventional screen and catalyst size combinations. The catalyst has an average pill diameter in the range of 1.6 mm to 3.0 mm, and the slot width of the screen is in the range of about 30% to about 60% of the pill diameter.

Disclosed is a catalyst comprising: a composition having a formula BN.sub.xM.sub.yO.sub.z wherein B represents boron, N represents nitrogen, M comprises a metal or metalloid, and O represents oxygen, x ranges from 0 to 1, y ranges from 0.01 to 5.5; and z ranges from 0 to 16.5. The catalyst may be suitable for converting alkanes to olefins.

The invention relates to polyoxometalates represented by the formula (A.sub.n).sup.m+[MM.sub.12X.sub.8O.sub.yR.sub.zH.sub.q].sup.m or solvates thereof, corresponding supported polyoxometalates, and processes for their preparation, as well as corresponding metal clusters, optionally in the form of a dispersion in a liquid carrier medium or immobilized on a solid support, and processes for their preparation, as well as their use in reductive conversion of organic substrate.

The present invention relates to a hydrocarbon conversion catalyst system comprising: a first composition comprising a dehydrogenation active metal on a solid support; and a second composition comprising a transition metal on an inorganic support and a hydrocarbon conversion process utilizing the hydrocarbon conversion catalyst system.