Peijun Cong

Kombinatorische Parallelsynthese und Hochgeschwindigkeitsrasterung von Heterogenkatalysator-Bibliotheken

Weniger als eine Minute war notig, um die katalytische Aktivitat und die Selektivitat eines Elements in einer kombinatorischen Bibliothek aus ternaren Rh-Pd-Pt-Cu-Legierungen zu bestimmen. Damit genugten zwei Stunden fast, um eine Bibliothek aus 136 Elementen zu uberprufen. Die Bibliotheken enthielten die Elemente (ca. 2–4 μg Material jeweils) in zweidimensionaler Anordnung und wurden mit Dunnschichttechniken synthetisiert. Zur Analyse wurden sie unter Einsatz von Rastertechniken, die mit Massenspektrometrie gekoppelt waren (siehe Bild), vermessen.

Combinatorial heterogeneous catalysis: oxidative dehydrogenation of ethane to ethylene, selective oxidation of ethane to acetic acid, and selective ammoxidation of propane to acrylonitrile

The application of combinatorial methods to three reactions catalyzed by multimetal oxides is described. Catalysts for the oxidative dehydrogenation of ethane to ethylene were tested using a 121- or 144-channel scanning mass spectrometer primary screening reactor and a 48-channel fixed bed secondary screening reactor; catalysts for the selective oxidation of ethane to acetic acid were tested using a 256-channel massively parallel microfluidic reactor primary screen alone, and catalysts for the selective ammoxidation of propane to acrylonitrile were tested using the massively parallel microfluidic reactor and an eight-channel fixed bed secondary/tertiary screening reactor. The details regarding catalyst design, synthesis, and screening are presented. This work has resulted in both the confirmation of published results and the generation of new lead materials for all three chemistries.

High-throughput synthesis and screening of Nb and Ta containing mixed metal oxide libraries for ethane oxidative dehydrogenation

Abstract Niobium and tantalum containing mixed metal oxide libraries (16×16×16 ternary libraries) of V-Al-Nb, Cr-Al-Nb and Cr-Al-Ta are prepared and screened for ethane oxidative dehydrogenation. An apparatus for screening catalytic activity and selectivity of a 144-member catalyst library prepared on a 3” quartz wafer was constructed. It consists of a reaction chamber, remote and optical and mass selective detectors. In the reaction chamber, each library member is heated individually by a CO 2 laser and reactant gases are delivered locally to each member. The reaction products, ethylene and CO 2 , are detected by photothermal deflection spectroscopy and by mass spectrometry respectively. The catalytic activities obtained showed that V-Al-Nb oxide catalysts are high temperature catalysts and Nb does not affect the catalytic activity of the V-Al oxides, in contrast to the effect of Nb found in Mo-V-Nb oxides. However, for the Cr-Al-Nb oxide library, the most active catalyst contains about 4% Nb. Similarly, the most active catalyst in the Cr-Al-Ta oxide library contains about 9% Ta. These results suggest that a fine composition mapping is necessary for discovery of new heterogeneous catalysts in the ternary systems.