Charge-Redistribution-Enhanced Nanocrystalline Ru@IrOx Electrocatalysts for Oxygen Evolution in Acidic Media

Abstract

A core-shell Ru@IrO x heterostructured nanocrystal was designed and constructed to be OER electrocatalyst in acidic media. Enhanced by strong charge redistribution across the core-shell heterojunction, this catalyst not only breaks the activity and stability limits of RuO 2 and IrO 2 simultaneously but also outperforms most of the known acidic OER electrocatalysts. This project offers a new idea to simultaneously enhance electrocatalytic activity and stability by inducing charge redistribution within heterostructured electrocatalysts.

Recent Advances on Water‐Splitting Electrocatalysis Mediated by Noble‐Metal‐Based Nanostructured Materials

“…The Ru/Pt core/shell structure with high compressive strain (Figure 9e,f)61 has optimized adsorption–desorption energetics toward H intermediates and OH spectator species relative to pure Pt and analogous PtRu alloy with identical ligand effect but without strain, illustrating that the strain effect in bimetallic electrocatalysts plays a more dominant role in accelerating HER kinetics in alkaline electrolyte. Moreover, the same group demonstrated the fabrication of heterostructured Ru@IrO x in which there is a strong charge redistribution across interface between the highly strained ruthenium core and a partially oxidized iridium shell 62. Benefiting from favorable valence states of Ru and Ir, the synergistic electronic and structural interaction were activated, leading to superior OER performance with enhanced activity and good durability.…”

“…Copyright 2018, American Chemical Society. g–i) Reproduced with permission 62. Copyright 2019, Elsevier.…”

Ultrafine Defective RuO2 Electrocatayst Integrated on Carbon Cloth for Robust Water Oxidation in Acidic Media

“…However, the efficiency of such device is limited by high Ohmic resistance of alkaline electrolyte and low operating pressure. [9][10][11][12][13][14][15][16][17][18][19][20][21][22][23] Compared with iridium oxides, ruthenium oxides possess higher OER activity and lower cost, but lower stability. Unfortunately, the widespread application of PEM electrocatalysis is restricted by the lack of efficient and durable electrocatalysts for oxygen evolution reaction (OER) in acidic media.…”

Interface Electronic Coupling in Hierarchical FeLDH(FeCo)/Co(OH)2 Arrays for Efficient Electrocatalytic Oxygen Evolution

“…These hybrid catalysts modified by conductive metals or effective promotors always show enhanced electron transfer, reduced overpotential, and improved durability. For example, the Ru@IrO x catalyst reported by Qiao and coworkers showed attractive OER performance that originated from its specific hybrid structure …”

“…tractive OER performance that originated from its specific hybrid structure. [39] Herein, we report the fabrication of hierarchical FeLDH(Fe-Co)/Co(OH) 2 arrays on carbon cloth through growth of 2D-ZIF-67 (ZIF = zeolitici midazolate framework) by ion-exchange and electrodeposition methods. The time-dependent transformation of 2D-ZIF-67 into Co(OH) 2 and hierarchical FeLDH(FeCo)/ Co(OH) 2 catalysts was systematically investigated.…”