Atomic Single-Layer Ir Clusters Enabling 100% Selective Chlorine Evolution Reaction

The exclusive selectivity of the chlorine evolution reaction (CER) is crucial for the chlor-alkali industry to obtain pure chlorine gas and avoid the cost of separating the byproduct oxygen. However, 100% CER selectivity remains a challenge for the currently known CER catalysts. Here, we report a catalyst of atomic single-layer Ir clusters on CeO2 nanorods (IrSL/CeO2). Under the strong metal/support interaction, IrSL has a strong adsorption to oxygen, thereby suppressing the oxygen evolution reaction. Coupled with the uniform active sites of the single-layer Ir clusters, IrSL/CeO2 achieves almost 100% CER selectivity in acidic NaCl solution ranging from open circuit potential to practical current density levels. In addition, IrSL/CeO2 exhibits 1.7 times higher catalytic activity than its single-atom counterparts, and its noble metal efficiency is 84 times higher than that of commercial anodes (DSAs). Our finding provides a solution to the selective catalysis of chlor-alkali electrolysis.