Direct Reuse of Industrial HCl Contaminants via Highly Selective Oxychlorination Phenols

The reuse of hazardous HCl contaminants containing various impurities is a challenging issue in academia and industry. An efficient method for the direct utilization of industrial HCl contaminants has been developed based on the oxychlorination of phenol using hydrogen peroxide as an oxidant. By employing HCl from hydrochloric acid contaminants as a chlorinating agent, 87–94% of HCl was effectively reused for the synthesis of chlorophenols. The process achieved complete conversion of phenol and highly selective oxychlorination of the C–H bonds of phenol at both ortho- and para-positions, particularly forming 2,4-dichlorophenol, in the presence of reaction-promoting additives. Various characterizations indicated that the surfactants promoted the formation of stable aggregates. The reaction primarily occurred at the aggregates interface, with diameters less than 100 nm. These aggregates exert a nanoscale limiting effect on the spatial structure of phenol, resulting in the highly selective formation of 2,4-dichlorophenol during the oxidative chlorination of phenol with HCl. This method demonstrates a highly efficient treatment rate for HCl pollutants containing impurities.