Shenheng Guan

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.

Gas phase oxidation of ethane to acetic acid using high-throughput screening in a massively parallel microfluidic reactor system

Abstract High-throughput primary synthesis and screening methods have been applied to the heterogeneously-catalyzed gas phase oxidation of ethane to acetic acid using mixed metal oxide catalysts. The discovery libraries consisted of 16×16 arrays of 256 catalysts on 3″×3″ quartz wafers. Catalysts were prepared using automated liquid-dispensing techniques and screened in parallel for catalytic activity in a Symyx Technologies 256-channel microfluidic reactor. Product detection was performed using parallel colorimetric techniques on products adsorbed on silica-coated glass TLC plates. This workflow allows the screening of more than 3000 samples per day. Promising leads were confirmed in focus libraries and are being optimized in secondary screening. MoV was identified as the most active binary of redox metals and was subsequently doped with main group, rare earth, and transition metals to form ternaries. Prior art MoVX (X=Nb, Ni, Sb) catalysts were successfully reproduced and it was shown that Pd doping significantly increases the catalytic activity of these systems. Three novel MoVY ternary systems were discovered.