Applications to Catalysis and Environmental Science

To understand catalytic reactions it is indispensable to characterize catalytic materials and to clarify static and dynamic stmctures of reaction intermediates as well as active sites of reactions. Paramagnetic species are in general involved in many catalytic reactions as reaction intermediates and/or active sites, especially in heterogeneous catalytic reactions. Thus, the ESR method has played an important role to get valuable information on catalytic and/or surface reactions with high selectivity and high sensitivity, which has not been achieved by any other methods. 

With recent advancement in the measurement techniques and the data analysis methods ESR spectroscopy is an increasingly important tool in the studies on catalysis and solid surfaces. This chapter focuses on the following five specific subjects relevant to the ESR applications in catalysis and environmental science (a) nitric oxide (NO) adsorbed on zeolites, (b) Cu(I)-NO complexes formed in zeolites, (c) structure and dynamics of organic radicals in zeolites, (d) titanium dioxide (Ti02) semiconductor photo-catalysis, and (e) the superoxide (O2 ) ion radical. 

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HYSCORE spectra take longer to record than 2- and 3-pulse ESEEM. As mentioned above, the technique is therefore more commonly applied to orientationally disordered systems, e.g. frozen solutions in chemical and biochemical applications, heterogeneous samples in applications to catalysis and environmental sciences. 

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