Breaking the Activity and Stability Bottlenecks of Electrocatalysts for Oxygen Evolution Reactions in Acids

Abstract

Oxygen evolution reaction (OER) is a cornerstone reaction for a variety of electrochemical energy conversion and storage systems such as water splitting, CO2/N2 reduction, reversible fuel cells, and metal‐air batteries. However, OER catalysis in acids suffers from extra sluggish kinetics due to the additional step of water dissociation along with its multiple electron transfer processes. Furthermore, OER catalysts often suffer from poor stability in harsh acidic electrolytes due to the severe dissolution/corrosion processes. The development of active and stable OER catalysts in acids is highly demanded. Here, we review the recent advances in OER electrocatalysis in acids and summarise the key strategies to overcome the bottlenecks of activity and stability for both noble‐metal‐based and noble metal‐free catalysts, including i) morphology engineering, ii) composition engineering, and iii) defect engineering. Recent achievements in operando characterization and theoretical calculations are summarised which provide an unprecedented understanding of the OER mechanisms regarding active site identification, surface reconstruction, and degradation/dissolution pathways. Finally, we offer our views on the current challenges and opportunities to break the activity‐stability relationships for acidic OER in mechanism understanding, catalyst design, as well as standardised stability and activity evaluation for industrial applications such as proton exchange membrane water electrolysers and beyond.This article is protected by copyright. All rights reserved

Metastable-Phase Two-Dimensional Metal Oxides for Advanced Electrocatalysis

“…Similar to IrO 2 , RuO 2 also exhibits an excellent catalytic performance in electrolytic water. Furthermore, RuO 2 is more cost-effective and abundant comparing to IrO 2 , presenting a more promising outlook. − Additionally, by harnessing the advantages of metastable-phase 2D materials, it becomes feasible to design highly efficient electrolytic water catalysts utilizing RuO 2 . , …”

Stabilizing Lattice Oxygen through Mn Doping in NiCo2O4‐δ Spinel Electrocatalysts for Efficient and Durable Acid Oxygen Evolution

“…[5][6][7] Great efforts have been devoted to decrease the content of those noble metal in various acid OER catalysts. [8][9][10] Series strategies have been developed to fabricate numerous catalysts with less used noble metal, such as surface segregation (IrO x / SrIrO 3 ), [11][12][13][14] single atoms catalysts (IrÀ NiCo 2 O 4 ), [1,[15][16][17][18] interface engineering (Co 3 O 4 /CeO 2 ), [19][20][21][22] doping method (NiÀ RuO 2 ), [23][24][25][26] and so on. Although those catalysts used little noble metal show an excellent performance for acid OER, it is still a big challenge to design acid OER catalysts without noble metal with improved activity and stability.…”

Transition metal-based electrocatalysts for alkaline overall water splitting: advancements, challenges, and perspectives

“…14 The best electrocatalysts for splitting water are based on noble metals, including Pt- and Ir/Ru-based compounds. 15 However, the limited availability of resources and the high cost significantly restrict the scope of the potential applications of these materials. 16,17 Therefore, developing high-quality noble metal-free or noble metal doped transition metal (TM) electrocatalysts is crucial for commercialising large-scale water electrolysis.…”