Comparison of the Different Catalytic Systems

A useful criterion for comparing catalysts is the turnover frequency (TOP mol product per mol catalyst per unit time, usually expressed as h ). For heterogeneous catalysts, where the active species may constitute only a small fraction of the total weight, productivity (g product per g catalyst per unit time) can be more useful. 

We have attempted to compare the activities of different catalysts in epoxida-tions with TBHP and H2O2 in Tables 2 and 3, respectively. A meaningful com- 

The only successful heterogeneous catalyst for epoxidations with H2O2, TS-1, is compared with state-of-the-art homogeneous systems in Table 4. 

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