Design Principles for Dual-Element-Doped Carbon Nanomaterials as Efficient Bifunctional Catalysts for Oxygen Reduction and Evolution Reactions

Dual-element-doped carbon nanomaterials are demonstrated to be more efficient bifunctional catalysts than noble metals to catalyze two key chemical reactions: oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) in regenerative fuel cells and metal air batteries. Moreover, to accelerate the search for the best metal-free catalysts, an activity descriptor is identified for the codoped carbon nanomaterials, which correlates doping structures to their catalytic activities. These predictions are supported by experimental data. Our work also predicts that the synergistic effect of codoping occurs within a certain distance between the codopants. The descriptor enables rational design of new bifunctional catalysts.