Coupling of Heteroatom Dopants and Intrinsic Carbon Defects for High-Efficiency Electrocatalytic Oxygen Reduction

Defective engineering of carbon, including introduction of heteroatom dopants and creation of intrinsic carbon defects, to alter the surface electronic/spin state of the carbon matrix has become a vital research area of carbon-based catalysts toward oxygen reduction reaction (ORR). When the heteroatom dopants and carbon intrinsic defects in the carbon matrix are spatially close enough, they could couple each other and synergistically endow the active centers with special electronic structures that might greatly enhance the ORR catalytic activities of the carbon-based catalysts. In this concept, we propose a conceptual idea of coupling sites composed of heteroatom dopants and intrinsic carbon defects, systematically summarize the types of the coupling sites and their synergistic mechanisms for catalyzing the ORR, and present feasible ideas and major challenges for efficient construction and verification of the coupling sites. This concept might be enlightening for in-depth studies on the design, construction, and understanding the structure-activity relationship of high-efficiency active sites in the carbon-based catalysts. The synergistic effects of heteroatom dopants coupled with intrinsic carbon defects could be utilized to regulate the electronic structures of carbon matrix, which endow carbon-based catalysts with remarkable catalytic activities. In this concept, synthesis strategies and synergistic mechanisms of such coupling sites are summarized, and the challenges and perspectives in development of the carbon-based catalysts with such coupling sites are presented.+image