September, 15 2010:
In situ and Operando Raman during catalytic reaction: assessing structure-activity relationships and providing real-time catalytic monitoring
Prof. Dr. Miguel A. Bañares
Catalytic Spectroscopy Laboratory
CSIC - Insitute for Catalysis, Madrid, Spain (EU)
Catalysis science stands on knowledge as a key ingredient to support further progress. Being able to determine which structure, is efficient for a given reaction step is a key ingredient to understand how it operates and, ultimately, controlling its performance. Conventional spectroscopic studies of fresh and used catalysts are informative, but the actual state of a catalyst during catalytic operation is rarely related to the fresh and spent catalysts. The structural transformations account for the significant transient activation or deactivation processes exhibited by many industrial catalytic systems. The advantage of operando methodologies is that catalytic performance changes can be directly linked to structural changes of the catalytic material. The strong influence of the reaction environment on the actual catalyst structure is the driving force to combine in situ studies under actual catalytic operation with simultaneous catalytic activity/selectivity measurement. Such combination of experiments is the basic idea of Operando Methodology, which was introduced into the catalysis literature seven years ago [Guerrero-Pérez and Bañares, 2002, Bañares et al., 2002, Bañares and Wachs, 2002]. The term “operando” provides a single word that underlines the simultaneous evaluation of both catalyst active site structure and catalytic activity/selectivity. It is critical that an operando reactor cell satisfies the requirements of both an in situ cell and those of a catalytic reactor used for the targeted reaction.
The application of operando Raman spectroscopy coupled to simultaneous gas chromatography and quadrupole mass spectrometry will be presented during the gas-solid reactions and during liquid phase reaction.
