Heterogeneous process hydrogen peroxide concentration

A different type of chemistry has been realized in the process commercialized by EniChem in 1986, which is based on employment of and the titanium-silicalite TS-1 as heterogeneous catalyst [106, 111]. The hydroxy lation mechanism involves activation of hydrogen peroxide via the formation of a titanium hydroperoxo complex, TiOOH, followed by electrophilic oxygen atom transfer to phenol. Methanol and acetone are the solvents of choice to achieve high selectivity. The nature of solvent, phenol concentration, reaction time, and size of catalyst particles affect the CAT/ HQ ratio. The TS-l-based process offers clear advantages in terms of conversion, selectivity, efficiency (see Table 14.1), catalyst separation/recycling, and, hence, environmental impact. 

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