Self-Supported Iridium Oxide Nanostructures for Electrocatalytic Water Oxidation in Acidic Media

Abstract

One major obstacle in the advancement of proton exchange membrane (PEM) technology is the development of highly active and durable electrocatalysts for the oxygen evolution reaction (OER) in an acid environment. In comparison with conventional catalysts in the powdery form, the selfsupported nanostructures are more promising for practical applications. However, the preparation of self-supported nanocatalysts with high stability in acidic media remains challenging. Herein, IrO x nanostructures anchored on carbon cloth were prepared by a facile two-step method, which involved a fast dip-coating process and a subsequent annealing treatment under different temperatures. High hydroxide contents and mixed valence of iridium were observed for the obtained samples. By optimizing the annealing temperature, we achieved a low overpotential of 220 mV at the current density of 20 mA cm −2 . The optimal activity was attributed to a balance between hydroxide content and electrochemical surface area. Moreover, the selfsupported IrO x nanostructure showed a good stability over 50 h.

Electrochemical Synthesis and Investigation of Stoichiometric, Phase-Pure CoSb2O6 and MnSb2O6 Electrodes for the Oxygen Evolution Reaction in Acidic Media

“…This result shows that it is possible to produce an acid-stable oxide containing OER active elements such as Co. However, as we mentioned previously, the performance of CoSb 2 O 6 and MnSb 2 O 6 is not good enough to replace state-of-the-art OER catalysts in acidic media. , For example, iridium oxide-based OER catalysts can achieve 10 mA/cm 2 with an overpotential of 0.20–0.35 V. ,− Thus, future work will focus on the identification of oxide compositions where the atomic ratio of a catalytically active metal to a metal that provides structural stability can be increased while retaining the stability of the compound in acidic media.…”

Galvanostatic Electrodeposition of Durable IrOx Films on Low-Iridium-Supported Titanium for an Acidic Oxygen Evolution Reaction

“…Compared with other samples, the electrodeposited IrO x -Ti electrodes at low deposition current density show longer accelerate life. Especially the electrode electrodeposited at 0.1 mA cm –2 for 5 h has an ALT of 73.21 h, which is much more stable than those reported in previous literature ,− (as shown in Table S1, most of them are lower than 15 h). In fact, the actual service lifetime is 200–300 times of the ALT according to the Hideo Tamura experience formula, concluding that its actual working life is at least 14,642 h, that is, 610 days.…”

Self-Supported WO3@RuO2 Nanowires for Electrocatalytic Acidic Water Oxidation

“…Moreover, the highly corrosive conditions in acidic environments at high oxidation potentials present a significant challenge in the development of efficient and stable OER catalysts. 7 To date, catalysts derived from the noble metal iridium (Ir), along with their corresponding metal oxides, have demonstrated the capability to fulfill the necessary criteria for the practical implementation of PEMWE. 8−10 The scarcity and relatively low intrinsic activity impede Ir-based catalysts for industrial-scale hydrogen (H 2 ) production.…”