CuCl 2 /FeCl 3 Bimetallic Photocatalyst for Sustainable Ethylene Production from Ethanol via Recoverable Redox Cycles.

Photocatalytic conversions of ethanol to valuable chemicals are significant organic synthesis reactions. Herein, we developed a CuCl 2 /FeCl 3 bimetallic photocatalyst for sustainable dehydration of ethanol to ethylene by recoverable redox cycles. The selectivity of ethylene was 98.3% for CuCl 2 /FeCl 3 , which is much higher than that of CuCl 2 (34.5%) and FeCl 3 (86.5%). Due to the ligand-to-metal charge transfer (LMCT) process involved in generating the liquid products, the CuCl 2 /FeCl 3 catalyst will be reduced to CuCl/FeCl 2 . Oxygen (O 2 ) is required for the recovery of CuCl 2 /FeCl 3 to avoid exhaustion. The soluble Fe 3+ /Fe 2+ redox species deliver catalyst regeneration properties more efficiently than single metal couples, making a series of redox reactions (Cu 2+ /Cu + , Fe 3+ /Fe 2+ , and O 2 /ethanol couples) recyclable with synergistic effects. A flow reactor was designed to facilitate the continuous production of ethylene. The understanding of bimetallic synergism and consecutive reactions promotes the industrial application process of photocatalytic organic reactions.