Stable Multifunctional Single-Atom Catalysts Adsorbed On Pyrazine-Modified Graphyne

Highly efficient single-atom catalysts (SACs) with maximal utility rate of metal atoms hold great promise in the energy storage devices. Support materials which can not only firmly anchor the active metal atoms but also modulate the catalytic activity are crucial for SACs. Here, we demonstrate from first-principles that the unique pores of pyrazine-modified graphyne (pyGY) which has been synthesized in recent experiments are quite promising for anchoring transition-metal (TM) atoms to achieve SACs due to the TM-N2 units. Among the ten TM@pyGYs, we filtered out two bifunctional SACs, Co@pyGY and Pt@pyGY, as efficient water splitting (HER/ OER) and metal-air battery (OER/ORR) catalysts, respectively. More interestingly, Ni@pyGY and Pd@pyGY can act as efficient HER/OER/ORR trifunctional electrocatalysts. These multifunctional catalysts have the overpotentials comparable or superior to those of the conventional unifunctional catalysts. This work provides a new group of promising multifunctional SACs, as well as a useful guidance for electrocatalyst design.