ZrO2?SiO2 mixed oxides as supports for platinum catalysts

Mixed ZrO₂–SiO₂ oxides were prepared by the sol-gel method and used as supports for platinum catalysts. Activity tests show that Pt/ZrO₂–SiO₂ catalysts can be used in the aromatization of n-heptane.     

Oxidative dehydrogenation of propane over Mo/g-Al2O3. effect of precursor

Alumina supported molybdenum oxide was prepared using ammonium heptamolybdate and molybdenum acetate as different precursors. The catalysts were characterized by BET, AAS, SEM-EDAX, XRD, TPR and surface acidity measurements. The characterization results and the catalytic behavior in oxydehydrogenation of propane were similar irrespective of precursor. This revised version was published online in August 2006 with corrections to the Cover Date.     

Docking Strategy To Construct Thermostable,Single‐Crystalline,Hydrogen‐Bonded Organic Framework with High Surface Area

Enhancing thermal and chemical durability and increasing surface area are two main directions for the construction and improvement of the performance of porous hydrogen‐bonded organic frameworks (HOFs). Herein, a hexaazatriphenylene (HAT) derivative that possesses six carboxyaryl groups serves as a suitable building block for the systematic construction of thermally and chemically durable HOFs with high surface area through shape‐fitted docking between the HAT cores and interpenetrated three‐dimensional network. A HAT derivative with carboxybiphenyl groups forms a stable single‐crystalline porous HOF that displays protic solvent durability, even in concentrated HCl, heat resistance up to 305 °C, and a high Brunauer–Emmett–Teller surface area [SA_(BET)] of 1288 m² g^?1. A single crystal of this HOF displays anisotropic fluorescence, which suggests that it would be applicable to polarized emitters based on robust functional porous materials.     

Acyclic diene metathesis (ADMET) depolymerization of functionalized furan-based polymers

Acyclic dience metathesis (ADMET) depolymerization of functionalized furan-based polymers prepared via aqueous ring-opening polymerization of 7-oxanobornenes has been investigated. Results indicate that while very high molecular weight poly [exo-N-methyl-7-oxabicyclo [2.2.1] hept-2,5-diene-2,3-dicarboximide] can be depolymerized to oligomers with ease, poly [2,3-dicarbomethoxy-7-oxabicyclo [2.2.1] hept-2,5-diene] is more resistant to depolymerization under similar conditions. This difference may be due to differential interaction of the carbonyls in the side chains with the metal atom of the catalyst in the proposed metallacyclobutane intermediate. ADMET depolymerization of poly [2,3-bis (trifluoromethyl)-7-oxabicyclo [2.2.1] hept-2,5-diene] was feasible, however, the extent of depolymerization was decreased due to the use of a coordinating solvent (THF) used during the depolymerization process. © 1994 John Wiley & Sons, Inc.