Developing high-performance electrocatalysts toward hydrogen evolution reaction is important for clean and sustainable hydrogen energy, yet still challenging. Herein, we report a single-atom strategy to construct excellent metal-organic frameworks (MOFs) hydrogen evolution reaction electrocatalyst (NiRu_0.13-BDC) by introducing atomically dispersed Ru. Significantly, the obtained NiRu_0.13-BDC exhibits outstanding hydrogen evolution activity in all pH, especially with a low overpotential of 36 mV at a current density of 10 mA cm⁻² in 1 M phosphate buffered saline solution, which is comparable to commercial Pt/C. X-ray absorption fine structures and the density functional theory calculations reveal that introducing Ru single-atom can modulate electronic structure of metal center in the MOF, leading to the optimization of binding strength for H₂O and H*, and the enhancement of HER performance. This work establishes single-atom strategy as an efficient approach to modulate electronic structure of MOFs for catalyst design.

Metal-organic frameworks (MOFs) have been recognized as compelling platforms for the development of miscellaneous applications because of their structural diversity and functional tunability. Here, we propose that the electrocatalytic properties could be well modified by incorporating missing linkers into the MOF. Theoretical calculations suggest the electronic structure of MOFs can be tuned by introducing missing linkers, which improves oxygen evolution reaction (OER) performance of the MOF. Inspired by these aspects, we introduced various missing linkers into a layered-pillared MOF Co₂(OH)₂(C₈H₄O₄) (termed as CoBDC) to prepare missing-linker MOFs. Transmission electron microscope and synchrotron X-ray measurements confirmed that the missing linkers in the MOF could be introduced and well controlled by our strategy. The self-supported MOF nanoarrays with missing linkers of carboxyferrocene exhibit excellent OER performance with ultralow overpotential of 241 mV at 100 mA cm⁻². This work opens a new prospect to develop efficient MOF-based electrocatalysts by introducing missing linkers.