Bifunctional HER/OER or OER/ORR Catalytic Activity of Two-Dimensional TM3(HITP)2 with TM = Fe–Zn

The designability of metal–organic frameworks (MOFs) offers a promising platform for development of multifunctional electrocatalysts for hydrogen evolution reaction (HER), oxygen evolution reaction (OER), and oxygen reduction reaction (ORR) which are long-desired in wide-range applications, such as overall water splitting, fuel cells, and metal–air batteries. On the basis of the recent experimental progresses, we proposed from first-principles a family of two-dimensional (2D) MOFs, consisting of transition metal (TM) atoms (TM = Fe–Zn) and 2,3,6,7,10,11-hexaiminotriphenylene (C18H12N6) functional group (HITP), namely TM3(HITP)2, with versatile multifunctional catalytic activity, which can be ascribed to synergistic effects of TM and organic ligands. Cu3(HITP)2 can serve as a bifunctional catalyst for HER and OER, while Fe3(HITP)2, Co3(HITP)2, and Zn3(HITP)2 are promising for both OER and ORR. The overpotentials of these TM3(HITP)2 monolayers are comparable or even superior to those of the well-developed noble catalysts. The tunable catalytic activity in the TM3(HITP)2 opens an avenue for design of low-cost and multifunctional catalysts and may find applications in the fields of clean and renewable energy.