Proton exchange membrane water electrolysis (PEMWEs) is a promising technology for energy conversion and storage due to its compatibility with renewable energy generation. The metal/metal oxide-support interaction can regulate the local electronic structure and promote the charge-transfer kinetics process. Herein, a well-aligned Ir-doped WO3 bifunctional catalyst loaded on a carbon paper substrate (denoted as Ir-WO3@CP) was designed and synthesized via a facile hydrothermal-electrodeposition method. The catalyst features an ultra-low-Ir loading (0.015 mgIr·cm−2) and a vertically oriented nanobelt array morphology. The Ir-WO3@CP electrode exhibits exceptional performance, achieving a current density of 100 mA·cm−2 at overpotentials (η) of just 39 mV for the hydrogen evolution reaction (HER) and 345 mV for the oxygen evolution reaction (OER) in 0.5 mol·L−1 H2SO4, respectively. The significantly enhanced mass-specific activity for both HER (10.3 <InlineEquation ID="IEq1"> <EquationSource Format="TEX">$\text{A} \, {\cdot}\, {\text{mg}}_{\rm{Ir}}^{-1}$</EquationSource> <EquationSource Format="MATHML"><math> <mrow> <mtext>A</mtext> <mspace width="0.166667em" /> <mo>·</mo> <mspace width="0.166667em" /> <msubsup> <mtext>mg</mtext> <mrow> <mi mathvariant="normal">Ir</mi> </mrow> <mrow> <mo>-</mo> <mn>1</mn> </mrow> </msubsup> </mrow> </math></EquationSource> </InlineEquation>, at − 50 mV vs. reversible hydrogen electrode (RHE)) and OER (3.13 <InlineEquation ID="IEq2"> <EquationSource Format="TEX">$\text{A} \, {\cdot}\, {\text{mg}}_{\rm{Ir}}^{-1}$</EquationSource> <EquationSource Format="MATHML"><math> <mrow> <mtext>A</mtext> <mspace width="0.166667em" /> <mo>·</mo> <mspace width="0.166667em" /> <msubsup> <mtext>mg</mtext> <mrow> <mi mathvariant="normal">Ir</mi> </mrow> <mrow> <mo>-</mo> <mn>1</mn> </mrow> </msubsup> </mrow> </math></EquationSource> </InlineEquation>, at 1.55 V vs. RHE) can be attributed to the optimized adsorption free energy of reaction intermediates induced by Ir doping, as well as the reduced W valence state, which accelerates OER and HER kinetics. Furthermore, the fully exposed active sites and highly dispersed Ir centers further maximize the utilization efficiency of the precious metal. When employed as both anode and cathode in a PEM water electrolyzer, Ir-WO3@CP stably operates for over 33 h, highlighting its potential for cost-effective hydrogen production. Graphical abstract

A well-aligned Ir-doped tungsten oxide self-supporting electrode via dopant-triggered activity to boost acidic water electrolysis

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发表日期：

2025年10月24日

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Jiao He,
Wen-Ting Zhang,
Ting-Ling Wu,
Jian-Cheng Hu,
Huan-Xin Li,
Da-Feng Yan,
Wei Hu

摘要

Proton exchange membrane water electrolysis (PEMWEs) is a promising technology for energy conversion and storage due to its compatibility with renewable energy generation. The metal/metal oxide-support interaction can regulate the local electronic structure and promote the charge-transfer kinetics process. Herein, a well-aligned Ir-doped WO₃ bifunctional catalyst loaded on a carbon paper substrate (denoted as Ir-WO₃@CP) was designed and synthesized via a facile hydrothermal-electrodeposition method. The catalyst features an ultra-low-Ir loading (0.015 mg_Ir·cm⁻²) and a vertically oriented nanobelt array morphology. The Ir-WO₃@CP electrode exhibits exceptional performance, achieving a current density of 100 mA·cm⁻² at overpotentials (η) of just 39 mV for the hydrogen evolution reaction (HER) and 345 mV for the oxygen evolution reaction (OER) in 0.5 mol·L⁻¹ H₂SO₄, respectively. The significantly enhanced mass-specific activity for both HER (10.3 $\text{A} \, {\cdot}\, {\text{mg}}_{\rm{Ir}}^{-1}$ $A \cdot {mg}_{Ir}^{- 1}$ , at − 50 mV vs. reversible hydrogen electrode (RHE)) and OER (3.13 $\text{A} \, {\cdot}\, {\text{mg}}_{\rm{Ir}}^{-1}$ $A \cdot {mg}_{Ir}^{- 1}$ , at 1.55 V vs. RHE) can be attributed to the optimized adsorption free energy of reaction intermediates induced by Ir doping, as well as the reduced W valence state, which accelerates OER and HER kinetics. Furthermore, the fully exposed active sites and highly dispersed Ir centers further maximize the utilization efficiency of the precious metal. When employed as both anode and cathode in a PEM water electrolyzer, Ir-WO₃@CP stably operates for over 33 h, highlighting its potential for cost-effective hydrogen production.

Graphical abstract