Methods of depolymerizing polyolefin-based material into useful petrochemical products using supported metal oxides and heat are described. The supported metal oxides improve the depolymerization reaction by decreasing the half time for the depolymerization, which results in a higher depolymerization rate and a shorter residence time in the depolymerization unit, allowing for a predictable depolymerization reaction, and decreasing the branching or aromatic formations in the product.

Method to prepare a catalyst for use in a process for the synthesis of methanol, comprising indium oxide in the form of In.sub.2O.sub.3, and at least one additional metal selected from a noble metal; and in that the average particle size of said noble metal phase is, preferably at least 0.05 nm, and less than 5 nm as determined by STEM-EDX, characterized in that the catalyst is prepared by co-precipitation of a saline solution at a pH above 8.5 comprising an indium salt and a salt of the at least one additional metal selected from a noble metal and optionally further comprising a salt of the at least one alkaline earth metal.

A supported catalyst for preparing light olefin using direct conversion of syngas is a composite catalyst and formed by compounding component I and component II in a mechanical mixing mode. The active ingredient of component I is a metal oxide; and the component II is a supported zeolite. A carrier is one or more than one of hierarchical pores Al.sub.2O.sub.3, SiO.sub.2, TiO.sub.2, ZrO.sub.2, CeO.sub.2, MgO and Ga.sub.2O.sub.3; the zeolite is one or more than one of CHA and AEI structures; and the load of the zeolite is 4%-45% wt. A weight ratio of the active ingredients in the component I to the component II is 0.1-20. The reaction process has an extremely high light olefin selectivity; the sum of the selectivity of the light olefin comprising ethylene, propylene and butylene can reach 50-90%, while the selectivity of a methane side product is less than 7%.

A supported catalyst for preparing light olefin using direct conversion of syngas is a composite catalyst and formed by compounding component I and component II in a mechanical mixing mode. The active ingredient of component I is a metal oxide; and the component II is a supported zeolite. A carrier is one or more than one of hierarchical pores Al.sub.2O.sub.3, SiO.sub.2, TiO.sub.2, ZrO.sub.2, CeO.sub.2, MgO and Ga.sub.2O.sub.3; the zeolite is one or more than one of CHA and AEI structures; and the load of the zeolite is 4%-45% wt. A weight ratio of the active ingredients in the component I to the component II is 0.1-20. The reaction process has an extremely high light olefin selectivity; the sum of the selectivity of the light olefin comprising ethylene, propylene and butylene can reach 50-90%, while the selectivity of a methane side product is less than 7%.

A composite catalyst containing heteroatom-doped zeolite for preparing light olefin using direct conversion of syngas formed by compounding component I and component II in a mechanical mixing mode. The active ingredient of component I is a metal oxide, and the component II is a heteroatom-doped zeolite. The zeolite topology is CHA or AEI, and the skeleton atoms include Al—P—O or Si—Al—P—O; the heteroatoms is at least one of divalent metal Mg, Ca, Cr, Mn, Fe, Co, Ni, Cu, Zn, Sr, Zr, Mo, Cd, Ba and Ce, trivalent metal Ti and Ga, and tetravalent metal Ge. A weight ratio of the active ingredient in the component I to the component II is 0.1-20. The reaction process has high light olefin selectivity; the sum selectivity of the light olefin including ethylene, propylene and butylene can reach 50-90%, while the selectivity of a methane side product is less than 7%.

A composite catalyst containing heteroatom-doped zeolite for preparing light olefin using direct conversion of syngas formed by compounding component I and component II in a mechanical mixing mode. The active ingredient of component I is a metal oxide, and the component II is a heteroatom-doped zeolite. The zeolite topology is CHA or AEI, and the skeleton atoms include Al—P—O or Si—Al—P—O; the heteroatoms is at least one of divalent metal Mg, Ca, Cr, Mn, Fe, Co, Ni, Cu, Zn, Sr, Zr, Mo, Cd, Ba and Ce, trivalent metal Ti and Ga, and tetravalent metal Ge. A weight ratio of the active ingredient in the component I to the component II is 0.1-20. The reaction process has high light olefin selectivity; the sum selectivity of the light olefin including ethylene, propylene and butylene can reach 50-90%, while the selectivity of a methane side product is less than 7%.

A process and catalyst are provided for the non-oxidative dehydrogenation of propane for the production of propylene as petrochemical building blocks. The process provides a direct single-step gas-phase dehydration of propane mixed with nitrogen in the presence and absence of steam/hydrogen over supported bimetallic alumina-silicates zeolites. The catalyst contains no precious metal entities and may contain one metal from group VIB in combination with another metal from group IIIA or IVA supported on FAU, MFI, KFI, BEA type alumina-silicates zeolites. The process provides a propane conversion of 18% to 52% with a propylene yield of 10% to 25%.

The present invention provides an In—NH.sub.2/g-C.sub.3N.sub.4 nanocomposites with visible-light photocatalytic activity and application thereof, which can effectively remove organic pollutants (such as tetracycline) in water. First, the graphite phase carbonitride carbon (g-C.sub.3N.sub.4) was obtained by thermal condensation, and g-C.sub.3N.sub.4 nanosheet was prepared by thermal oxidative etching. Then, acicular MIL-68(In)—NH.sub.2 (In—NH.sub.2) was grown in situ on the surface of g-C.sub.3N.sub.4 nanosheet by solvothermal method. The In—NH.sub.2/g-C.sub.3N.sub.4 nanocomposites with high visible-light photocatalytic activity were obtained. The CNNS firstly was prepared in the present invention, which is beneficial to the needle-like In—NH.sub.2 growing on the surface of CNNS and having close interfacial contact with each other, forming a heterojunction, promoting the separation of photogenerated electrons and holes pairs, and enhancing visible-light photocatalytic degradation of organic pollutants. The nanocomposites show high structural stability and reusability, which has great potential in the field of water remediation.

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.

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.