The reaction rate of hydrocarbon pyrolysis can be increased to produce solid carbon and hydrogen by the use of molten materials which have catalytic functionality to increase the rate of reaction and physical properties that facilitate the formation and contamination-free separation of the solid carbon. Processes, materials, reactor configurations, and conditions are disclosed whereby methane and other hydrocarbons can be decomposed at high reaction rates into hydrogen gas and carbon products without any carbon oxides in a single reaction step. The process also makes use of specific properties of selected materials with unique solubilities and/or wettability of products into (and/or by) the molten phase to facilitate generation of purified products and increased conversion in more general reactions.

Oxidative dehydrogenation catalysts comprising MoVNbTeO having improved consistency of composition and a 25% conversion of ethylene at less than 420 C. and a selectivity to ethylene above 95% are prepared by treating the catalyst precursor with H.sub.2O.sub.2 in an amount equivalent to 0.30-2.8 mL H.sub.2O.sub.2 of a 30% solution per gram of catalyst precursor prior to calcining.

Incorporating into a fixed bed reactor for an exothermal reaction having a catalyst supported on a support having a thermal conductivity typically less than 30 W/mk within the reaction temperature control limits heat dissipative particles having a thermal conductivity of at least 50 W/mk less than 30 W/mk within the reaction temperature control limits helps control the temperature of the reactor bed.

The preparation of an oxidative dehydrogenation catalyst comprising Mo, V, Nb and Te using a hydrothermal step. In some embodiments, the activity and reproducibility of the catalyst is improved by conducting the hydrothermal step while permitting gaseous products to leave the reactor. In some instances a condenser may be upstream of the outlet of the reactor.

A process for preparing an oxidative dehydrogenation catalyst or oxidative dehydrogenation catalyst precursor that includes mixing solutions of molybdenum and tellurium at a pH from about 3.3 to 7.5; adjusting the pH of the resulting solution back to about 5 and adding VOSO.sub.4 and adding a solution of Nb.sub.2O.sub.5 and oxalic acid and treating the resulting precursor slurry in a controlled pressure hydrothermal process to obtain the catalyst.

Oxidative dehydrogenation catalysts for converting lower paraffins to alkenes such as ethane to ethylene when prepared as an agglomeration, for example extruded with supports chosen from slurries of TiO.sub.2, ZrO.sub.2 Al.sub.2O.sub.3, AlO(OH) and mixtures thereof have a lower temperature at which 25% conversion is obtained.

Oxidative dehydrogenation catalysts comprising MoVNbTeO having improved consistency of composition and a 25% conversion of ethylene at less than 420 C. and a selectivity to ethylene above 95% are prepared by treating the catalyst precursor with H.sub.2O.sub.2 in an amount equivalent to 0.30-2.8 mL H.sub.2O.sub.2 of a 30% solution per gram of catalyst precursor prior to calcining.

Present subject matter provides a semiconductor nanocrystal comprises a core and a shell. The core is fabricated from a first semiconductor. The shell is fabricated from a second semiconductor. The optical cross section of the semiconductor nanocrystal is in a range of 10.sup.17 cm.sup.2-10.sup.12 cm.sup.2 in a 2-3 eV region. The core is less than 2 nanometers from an outer surface of the shell in at least one region of the semiconductor nanocrystal. Present subject matter also provides method for preparation of the semiconductor nanocrystals and method for photosynthesis of organic compounds.

The method disclosed herein relates to two stage catalytic processes for converting syngas to acetic acid, acrylic acid and/or propylene. More specifically, the method described and claimed herein relate to a method of producing acrylic acid and acetic acid comprising the steps of: a) providing a feedstream comprising syngas; b) contacting the feedstream with a first catalyst to produce a first product stream comprising C.sub.2-C.sub.3 olefins and/or C.sub.2-C.sub.3 paraffins; and c) contacting the first product stream with oxygen gas and a second catalyst, thereby producing a second product stream comprising acrylic acid and acetic acid, wherein there is no step for separating the components of the first product stream before the first product stream is contacted with the second catalyst.

A catalyst for oxidative dehydrogenation (ODH) of ethane with an empirical formula MoVTeNbPdO produced using a process comprising impregnation of the Pd component on the surface of the catalyst following a calcination step using a Pd compound free of halogens. The resulting catalyst can be used in both diluted and undiluted ODH processes and shows higher than expected activity without any loss of selectivity.