Electrocatalysts Derived from Metal–Organic Frameworks for Oxygen Reduction and Evolution Reactions in Aqueous Media

Abstract

Electrochemical energy conversion and storage devices such as fuel cells and metal-air batteries have been extensively studied in recent decades for their excellent conversion efficiency, high energy capacity, and low environmental impact. However, sluggish kinetics of the oxygen-related reactions at air cathodes, i.e., oxygen reduction reaction (ORR) and oxygen evolution reaction (OER), are still worth improving. Noble metals such as platinum (Pt), iridium (Ir), ruthenium (Ru) and their oxides are considered as the benchmark ORR and OER electrocatalysts, but they are expensive and prone to be poisoned due to the fuel crossover effect, and may suffer from agglomeration and leaching after long-term usage. To mitigate these limits, it is highly desirable to design alternative ORR/OER electrocatalysts with prominent performance. Metal-organic frameworks (MOFs) are a class of porous crystalline materials consisting metal ions/clusters coordinated by organic ligands. Their crystalline structure, tunable pore size and high surface area afford them wide opportunities as catalytic materials. This Review covers MOF-derived ORR/OER catalysts in electrochemical energy conversion, with a focus on the different strategies of material design and preparation, such as composition control and nanostructure fabrication, to improve the activity and durability of MOF-derived electrocatalysts.

Recent Advances in Materials and Design of Electrochemically Rechargeable Zinc–Air Batteries

“…Metal‐organic frameworks (MOFs) consist of metal ions or clusters coordinated to organic ligands in forms of 1D, 2D, or 3D structures, have recently become popular precursors and templates to synthesize various M–N–C materials . In general, there are several of advantages of using MOFs to synthesize electrocatalysts: i) some unique features of MOF precursors (e.g., large surface area and high porosity) can be preserved in the resultant electrocatalysts; ii) carbon matrixes resulted from organic frameworks have good electrical conductivity to enable fast electron transfer; iii) various heteroatoms (e.g., N, O, S, and P) in the organic ligands of MOFs can be directly doped into carbon matrixes, which might provide not only catalytically active sites but also a suitable environment for the formation of metal composite nanoparticles (e.g., transition metal carbides, nitrides, and oxides); iv) atomically dispersed metal atoms in MOFs can lead to homogeneously distributed metal or metal composite nanoparticles embedded in carbon matrixes; and v) the morphology, size, and structural characteristics of electrocatalysts can be changed by varying treatment conditions of MOFs …”

Synthesis of Fe, Co Incorporated in P-Doped Porous Carbon Using a Metal-Organic Framework (MOF) Precursor as Stable Catalysts for Oxygen Reduction Reaction

“…However, due to its expensive cost, poor durability, and CO poisoning in the reaction, [1][2][3][4][5] the need to explore new efficient, durable, and cheap catalysts to substitute the Pt/C is urgent. In past decades, several alternatives have been developed, such as noble metal-based nanoparticles, 5,6 non-noble metal catalysts, 7,8 and metal-free materials. 9 Heteroatom-doped carbon materials are the representatives of the metal-free materials and the mechanism of the reduction of oxygen has been widely investigated.…”

Secondary‐Component Incorporated Hollow MOFs and Derivatives for Catalytic and Energy‐Related Applications

“…[59] In order to replace the costly Pt-based catalysts, many nonprecious catalysts were broadly studied. [63] Considering that, the secondary component incorporated MOF derivatives could exhibit higher performance with precise manipulation of active species. [63] Considering that, the secondary component incorporated MOF derivatives could exhibit higher performance with precise manipulation of active species.…”