Efficient Electrophotochemical Microreactor for Direct Green Production of Phenol from Benzene

Electrophotocatalysis, a burgeoning and sustainable technique in the field of organic synthesis, faces challenges in practical implementation due to technological and equipment limitations. This work introduces the design and engineering of an electrophotocatalytic flow microreactor for efficient synthesis of phenol from benzene in one step. The study explored the effects of microreactor configuration and various parameters, such as applied voltage, light intensity, and the concentrations of oxidant DDQ and electrolyte TBABF4. The innovative microreactor, characterized by a compact electrode gap and an expansive optical window, achieved a high phenol yield of 21.2% within a short residence time of 10 min, a significant improvement over the 14.3% yield obtained by a batch reactor in 6 h. The microreactor delivered a remarkable phenol productivity of 116.8 mmol h–1 L–1, outperforming all previous electrophotocatalytic synthesis records. Furthermore, a techno-economic analysis demonstrated that small-scale electrophotocatalytic synthesis of phenol reduced the per-unit production cost, displaying economic advantages competitive with the traditional cumene method. This work provides valuable insights into the engineering of flow microreactors for electrophotocatalysis and offers guidance for the potential industrial-scale application of electrophotocatalytic flow reactions.