Hydrothermal Synthesis of Copper-Containing Pure-Silica MTW Zeolite and Efficient Catalytic Performance for Phenol...

The direct hydroxylation of phenol with hydrogen peroxide and catalysts is an atom-economical method. Copper-containing zeolites were found to be efficient catalysts in phenol hydroxylation. However, the presence of framework aluminum sites (acidic centers) in these copper-containing zeolites limits their application in phenol hydroxylation, as the acidic centers could accelerate the decomposition of hydrogen peroxide. In this work, we successfully synthesized a series of novel copper-containing pure-silica MTW zeolites (Cu-MTW), which was verified to be a highly efficient catalyst in phenol hydroxylation. The optimal catalyst, Cu-MTW-120, exhibited superior catalytic performance, achieving a TON of 334 and a turnover frequency of 56 h^-1. Remarkably, the Cu-MTW zeolite-mediated phenol hydroxylation process achieved a higher phenol conversion of 41% and dihydroxybenzene selectivity of 99%, respectively.