Research Progress of Perovskite-Based Bifunctional Oxygen Electrocatalyst in Alkaline Conditions

Abstract

In light of the depletion of conventional energy sources, it is imperative to conduct research and development on sustainable alternative energy sources. Currently, electrochemical energy storage and conversion technologies such as fuel cells and metal-air batteries rely heavily on precious metal catalysts like Pt/C and IrO2, which hinders their sustainable commercial development. Therefore, researchers have devoted significant attention to non-precious metal-based catalysts that exhibit high efficiency, low cost, and environmental friendliness. Among them, perovskite oxides possess low-cost and abundant reserves, as well as flexible oxidation valence states and a multi-defect surface. Due to their advantageous structural characteristics and easily adjustable physicochemical properties, extensive research has been conducted on perovskite-based oxides. However, these materials also exhibit drawbacks such as poor intrinsic activity, limited specific surface area, and relatively low apparent catalytic activity compared to precious metal catalysts. To address these limitations, current research is focused on enhancing the physicochemical properties of perovskite-based oxides. The catalytic activity and stability of perovskite-based oxides in Oxygen Reduction Reaction/Oxygen Evolution Reaction (ORR/OER) can be enhanced using crystallographic structure tuning, cationic regulation, anionic regulation, and nano-processing. Furthermore, extensive research has been conducted on the composite processing of perovskite oxides with other materials, which has demonstrated enhanced catalytic performance. Based on these different ORR/OER modification strategies, the future challenges of perovskite-based bifunctional oxygen electrocatalysts are discussed alongside their development prospects.

Porous Inorganic Nanomaterials: Their Evolution towards Hierarchical Porous Nanostructures

“…Xu et al formed hierarchical porous ε-MnO 2 from a manganite perovskite (LaMnO 3.15 ) using a template-free mineral acid etching process [94] to produce catalysts for low-temperature formaldehyde oxidation. The perovskites themselves are also porous metal oxides that also find application as catalysts [154]. Due to the prevalence of perovskites in solar cells, it is not surprising that hierarchically (nano-,meso-)porous perovskites have also been developed for this purpose [25].…”

High-Entropy Oxides as Electrocatalysts for the Oxygen Evolution Reaction: A Mini Review

“…25 in perovskite oxides could not only cause a change in the valence state of cations at A-site and B-site but also the generation of oxygen vacancies. 106 Double perovskites can be generated by doping cations, surface treatment, and nanostructure engineering to provide faster surface oxygen exchange and higher electrical conductivity (Figure 2a), which consist of A-site ordered perovskites (AA′B 2 O 6 ) and B-site ordered perovskites (A 2 BB′O 6 ), replacing the B-site with another transition metals, which has been confirmed to be a better strategy that can effectively adjust d-band center to the Fermi level. 107 Triple perovskite can be regarded as a structure correlated to a cubic perovskite, which is characterized by a triple cubic axis.…”

“…B-site cations (typically transition metal ions) coordinate with six oxygen and inhabit the center of the cube, while oxygen anions occupy cube faces . Particularly, the partial substitution of A and/or B sites in perovskite oxides could not only cause a change in the valence state of cations at A-site and B-site but also the generation of oxygen vacancies . Double perovskites can be generated by doping cations, surface treatment, and nanostructure engineering to provide faster surface oxygen exchange and higher electrical conductivity (Figure a), which consist of A-site ordered perovskites (AA′B 2 O 6 ) and B-site ordered perovskites (A 2 BB′O 6 ), replacing the B-site with another transition metals, which has been confirmed to be a better strategy that can effectively adjust d-band center to the Fermi level .…”

Core–Shell CoS2@MoS2 with Hollow Heterostructure as an Efficient Electrocatalyst for Boosting Oxygen Evolution Reaction

“…Recently, transition-metal-based composites with earth-abundant sources and high efficiency have been proposed to substitute noble-metal catalysts. Many kinds of metal composites, including metal sulfides [12][13][14][15], metal phosphides [16,17], and metal oxides/hydroxides [18][19][20], have been demonstrated to show improved catalytic OER activity in an alkaline electrolyte. As confirmed by computational and experimental analyses, cobalt sulfides with a refined surface chemical state can be used as effective catalysts to facilitate the electrochemical reaction during the OER process [21,22].…”