| Autor: |
Bols ML; Laboratory for Chemical Technology (LCT), University of Ghent, Technologiepark Zwijnaarde 125, 9052 Ghent, Belgium., Ma J; Department of Microbial and Molecular Systems, Center for Sustainable Catalysis and Engineering, KU Leuven, Celestijnenlaan 200F, B-3001 Leuven, Belgium., Rammal F; Department of Microbial and Molecular Systems, Center for Sustainable Catalysis and Engineering, KU Leuven, Celestijnenlaan 200F, B-3001 Leuven, Belgium., Plessers D; Department of Microbial and Molecular Systems, Center for Sustainable Catalysis and Engineering, KU Leuven, Celestijnenlaan 200F, B-3001 Leuven, Belgium., Wu X; Department of Microbial and Molecular Systems, Center for Sustainable Catalysis and Engineering, KU Leuven, Celestijnenlaan 200F, B-3001 Leuven, Belgium., Navarro-Jaén S; Department of Microbial and Molecular Systems, Center for Sustainable Catalysis and Engineering, KU Leuven, Celestijnenlaan 200F, B-3001 Leuven, Belgium., Heyer AJ; Department of Microbial and Molecular Systems, Center for Sustainable Catalysis and Engineering, KU Leuven, Celestijnenlaan 200F, B-3001 Leuven, Belgium.; Department of Chemistry, Stanford University, Stanford, California 94305, United States., Sels BF; Department of Microbial and Molecular Systems, Center for Sustainable Catalysis and Engineering, KU Leuven, Celestijnenlaan 200F, B-3001 Leuven, Belgium., Solomon EI; Department of Chemistry, Stanford University, Stanford, California 94305, United States., Schoonheydt RA; Department of Microbial and Molecular Systems, Center for Sustainable Catalysis and Engineering, KU Leuven, Celestijnenlaan 200F, B-3001 Leuven, Belgium. |
| Abstrakt: |
This review highlights in situ UV-vis-NIR range absorption spectroscopy in catalysis. A variety of experimental techniques identifying reaction mechanisms, kinetics, and structural properties are discussed. Stopped flow techniques, use of laser pulses, and use of experimental perturbations are demonstrated for in situ studies of enzymatic, homogeneous, heterogeneous, and photocatalysis. They access different time scales and are applicable to different reaction systems and catalyst types. In photocatalysis, femto- and nanosecond resolved measurements through transient absorption are discussed for tracking excited states. UV-vis-NIR absorption spectroscopies for structural characterization are demonstrated especially for Cu and Fe exchanged zeolites and metalloenzymes. This requires combining different spectroscopies. Combining magnetic circular dichroism and resonance Raman spectroscopy is especially powerful. A multitude of phenomena can be tracked on transition metal catalysts on various supports, including changes in oxidation state, adsorptions, reactions, support interactions, surface plasmon resonances, and band gaps. Measurements of oxidation states, oxygen vacancies, and band gaps are shown on heterogeneous catalysts, especially for electrocatalysis. UV-vis-NIR absorption is burdened by broad absorption bands. Advanced analysis techniques enable the tracking of coking reactions on acid zeolites despite convoluted spectra. The value of UV-vis-NIR absorption spectroscopy to catalyst characterization and mechanistic investigation is clear but could be expanded. |
