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. Cu-3(HITP)(2) can serve as a bifunctional catalyst for HER and OER, while Fe-3(HITP)(2), Co-3(HITP)(2), and Zn-3(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.