Nature of Intrinsic Defects in Carbon Materials for Electrochemical Dechlorination of 1,2-Dichloroethane to Ethylene

Carbon materials have been recognized as prospective catalysts for the electrocatalytic 1,2-dichloroethane (DCE) dechlorination reaction (DCEDR), which is an economical and environmentally friendly strategy for the control of DCE contamination and production of highly valuable ethylene. However, the precise nature of intrinsic defects (pentagon, heptagon, octagon, armchair edge, and zigzag edge) in carbon-based catalysts for the electrochemical DCEDR has not been reported to date. Herein, theoretical calculations demonstrated that pentagon site showed the lowest energy barrier of 0.12 eV, indicating a much higher electrochemical reactivity and ethylene selectivity of pentagon defect than those of others. The prediction results have been proved experimentally based on a series of defective carbon materials with definitive defect configurations. Therefore, intrinsic defects played a significant role in the electrocatalytic DCEDR and pentagon defect was responsible for the high performance of defective carbon catalysts. This work not only clarifies the nature of intrinsic defects in carbon materials for electrochemical DCEDR but also provides the design principles for the rational preparation of advanced carbon electrocatalysts.