Substitutional phosphorus doping stimulates strong metal-support interactions for anion exchange membrane based alkaline seawater electrolysis

Abstract

The development of electrocatalysts with high catalytic activity and resistant to chlorine has become crucial for the large-scale implementation of seawater electrolysis. Here, the strong metal support interaction (SMSI) between Pt and NiMoO4 is enhanced by substitutional P atom-doping (P-Pt/NiMoO4@NF) to optimize the metal surrounding environment, realizing the efficient and anticorrosive seawater electrolysis. Density functional theory (DFT) reveals that substitutional P atom-doping can adjust the electronic structure to optimize the hydrogen adsorption free energy (ΔGH*) and decrease the adsorption energy of Cl- for the HER process. Benefiting from the SMSI caused by substitutional P atom-doping, the prepared P-Pt/NiMoO4@NF catalyst achieves a current density of 1.0 A cm−2 at an ultra-low overpotential of only 80 mV, surpassing the most reported Pt-based electrocatalysts. More importantly, in the anion exchange membrane (AEM) electrolyzer, the catalyst used as the cathode can drive 500 mA cm−2 under industrial conditions with only 1.75 V, while running steadily for 120 h, and with high efficiency and low price of H2 per gallon gasoline equivalent (GGE).