(439f) Electronic Structure Optimization of Metal-Phthalocyanine Via Confining Atomic Ru for All-pH Hydrogen Evolution

The eco-friendly production of hydrogen in actual working conditions is a promising method to address the energy crisis. Facing the gap of hydrogen evolution reaction kinetics in different conditions, recently, the introducing of noble-metal single atoms has been considered an effective way to boost electrocatalytic activity. However, electrochemical stability is poor in different conditions and the loaded metals are prone to precipitation and agglomeration on traditional substrates (such as metal oxides or hydroxides, etc.), and the complex composition of conventional supports hinders the exploration of structure-activity relationship. Meanwhile, the lack of an effective proton source and the sluggish electrolyzed water process have resulted in a large kinetics difference in hydrogen evolution at different pH conditions. Herein, we construct a two-dimensional metal-polyphthalocyanine (NiFe PPc) with clear and stable networks confining atomically Ru, through electrochemical deposition method. Benefiting from the electronic coupling effect from Ru-N bridges on NiFe PPc, the Ru_SA@NiFe PPc shows remarkable all-pH HER activity, featured by a low overpotential of 12 mV to reach 10 mA cm^-2 current density, which is nearly 50 times smaller than pristine NiFe PPc and outperforming the benchmark Pt/C catalyst. We further demonstrate that a proton exchange membrane water electrolysis (PEMWE) with Ru_SA@NiFe PPc and commercial IrO₂ anode achieves a current density of 2.0 A cm^-2 at a low voltage of only 2.27 V. And more importantly, we further demonstrate an alkaline electrolyzer with Ru_SA@NiFe PPc and stainless steel mesh (SSM), which displays excellent performance with achieving current densities of 2.0 A cm^-2 at cell voltages of 1.72 V. Theoretical calculations reveal that the electronic structure optimization through Ru-N bridge induces the acceleration of activation/dissociation water and adsorption of ^*H, thus breaking the deadlock of all-pH HER kinetics.