Reducing Iridium Loading in Oxygen Evolution Reaction Electrocatalysts Using Core–Shell Particles with Nitride Cores

Abstract

The oxygen evolution reaction (OER) has broad applications in electrochemical devices, but it often requires expensive and scarce Ir-based catalysts in acid electrolyte. Presented here is a framework to reduce Ir loading by combining core–shell iridium/metal nitride morphologies using in situ experiments and density functional theory (DFT) calculations. Several group VIII transition metal (Fe, Co, and Ni) nitrides are studied as core materials, with Ir/Fe4N core–shell particles showing enhancement in both OER activity and stability. In situ X-ray absorption fine structure measurements are used to determine the structure and stability of the core–shell catalysts under OER conditions. DFT calculations are used to demonstrate adsorbate binding energies as descriptors of the observed activity trends.

Ru@RuO2 Core‐Shell Nanorods: A Highly Active and Stable Bifunctional Catalyst for Oxygen Evolution and Hydrogen Evolution Reactions

“…Water electrolysis to generate hydrogen has received much attention recently . Electrochemical water splitting undergoes an oxygen evolution reaction (OER) at the anode and a hydrogen evolution reaction (HER) at the cathode . Highly active catalysts are regularly demanded to lower the overpotentials and accelerate the reaction rates at the electrode/electrolyte interface .…”

“…Highly active catalysts are regularly demanded to lower the overpotentials and accelerate the reaction rates at the electrode/electrolyte interface . The state‐of‐the‐art catalyst for HER is platinum supported on active carbon, and for OER is expensive iridium oxide (IrO 2 ) . Great efforts have been made to find more active, more stable, and inexpensive alternative OER and HER catalysts to replace rare and noble metals/oxides.…”

MOF‐Derived Ni‐Doped CoS2 Grown on Carbon Fiber Paper for Efficient Oxygen Evolution Reaction

“…The current density of bare CFP for OER is negligible, which is in good accordance with previous publications ,. Such excellent OER performance outperforms most recently reported noble metal‐free catalysts and even commercial IrO 2 (see details in Table ),, demonstrating great potential for electrocatalytic water oxidation applications.…”

Efficient Electrocatalytic Oxygen Evolution at Extremely High Current Density over 3D Ultrasmall Zero‐Valent Iron‐Coupled Nickel Sulfide Nanosheets

“…Numerous efforts have been devoted to develop low cost and highly efficient OER electrocatalysts, including transition metal nitrides,, phosphides, phosphates, oxides,, hydroxides,, oxyhydroxides,, and dichalcogenides . Among these transition metal compound electrocatalysts, nickel sulfides (Ni 3 S 2 , NiS 2 , α‐NiS, and β‐NiS) are considered among the most promising candidates as OER electrocatalysts for water electrolysis in alkaline media because of their good catalytic activity and natural abundance …”