Low-Dimensional Metal–Organic Frameworks with High Activity and Selectivity toward Electrocatalytic Chlorine Evolution Reactions

Chlorine gas plays a paramount role in modern industrial chemistry and is one of the most basic chemicals produced by the electrolysis of brine solution. In the past decades, the dimensionally stable anode (DSA) made of RuO2is the benchmark catalyst for the chlorine evolution reaction (CER) with high activity. However, the drawbacks of the DSA, such as high cost and inferior selectivity, demand the development of low-cost and efficient electrocatalysts for CER. Herein, three low-dimensional Fe/Co/Ni-dithiolene metal-organic frameworks (MOFs) were systematically investigated using the density functional theory. Our calculation results predict that Ni-based dithiolene MOF can efficiently catalyze the CER with a low thermodynamic overpotential of 0.049 V via the Cl∗ intermediate. The electronic resonance structure of [Ni2+(L•-)(L2-)]-in the Ni-based dithiolene MOF leads to the electron transfer first from S atoms in ligands to Ni cations to achieve a stable electronic configuration, which leads to the most desirable Ni-Cl interaction strength for CER. Moreover, the selectivity to Cl2generation is due to its high thermodynamic overpotential of oxygen evolution reaction. Our findings may, therefore, accelerate CER catalyst discoveries beyond DSAs with the optimized electronic structures.