Water-mediated promotion of direct oxidation of benzene over the metal–organic framework HKUST-1

Abstract

Pretreatment of a HKUST-1 catalyst with water significantly accelerated the catalytic oxidation of benzene to phenol and hydroquinone with hydrogen peroxide as an oxidant. The corresponding oxygenates had a yield of 36.5%, and the selectivity to phenol and hydroquinone was 53.2% and 35.5%, respectively. The turnover frequency (TOF) was 35.1 h⁻¹. Comparatively, the product yield was only 2.7% over the original HKUST-1, and the TOF was 2.6 h⁻¹. Moreover, water treatment protected HKUST-1 from decomposition due to formation of a new oxidation mode. Therefore, the catalytic system in the presence of water opened a new door towards a facile and efficient preparation of phenol and hydroquinone.