Metal–Organic Gel‐Derived Multimetal Oxides as Effective Electrocatalysts for the Oxygen Evolution Reaction

Abstract

Exploring efficient and durable catalysts derived from earth‐abundant and cost‐effective materials is a highly desirable route to overcome the sluggish anodic oxygen evolution reaction (OER). A series of multinary metal–organic gels (MOGs) with various and alterable metal element compositions are prepared by straightforward mixing of metal ions with ligand 4,4′,4′′‐[(1,3,5‐triazine‐2,4,6‐triyl)tris(azanediyl)]tribenzoic acid (H3TATAB) in solution at room temperature. Spinel‐type metal oxides with excellent electrocatalytic OER performance were then obtained through calcination of the as‐synthesized MOGs. In electrochemical testing, the trimetallic oxide CoFeNi‐O‐1 (derived from the MOG with a Co/Fe/Ni molar ratio of 5:1:4) exhibits remarkable catalytic activity with a low overpotential of 244 mV at a current density of 10 mA cm−2 and a small Tafel slope of 55.4 mV dec−1 in alkaline electrolyte, outperforming most recently reported electrocatalysts. This work not only provides a promising OER catalyst and enriches the application of MOGs in the catalytic field, but also offers a facile new route to acquiring multicomponent metal oxides with high electrocatalytic activity.

Hierarchical porous metal–organic gels and derived materials: from fundamentals to potential applications

“…In addition to ORR, MOG-based catalytic systems have also been employed in the oxygen evolution reaction (OER), CO 2 reduction reaction and methanol oxidation reaction (MOR). 319,326,327 The OER reaction is considered an essential reaction in metal-air batteries, water-splitting reactions and other energy storage and conversion devices. 328 In this context, Cao et al designed a trimetallic MOG based on a tritopic triazine tricarboxylate and Co, Ni and Fe ions (CoFeNi-1 MOG).…”

“…However, transfer of the wide spread concept of using MOFs as precursors/sacrificial templates for electrocatalysts, 119,317 to MOGs showed some promising results. [318][319][320][321][322] Hence, most of the work reported so far on MOGs used in electrocatalysis, involves the high temperature treatment of hybrid MOGs, yielding heteroatom rich carbon materials. 318,[323][324][325] The carbonization of MOGs generates a high surface area porous material with additional binding sites and polarity, which thus improves the electrochemical properties of MOGs.…”

Metal–Organic Frameworks and Metal–Organic Gels for Oxygen Electrocatalysis: Structural and Compositional Considerations

“…The networks after pyrolysis led to a high degree of surface area and good distribution of graphitic N; both were responsible for efficient alkaline ORR electrocatalysis. As for OER applications, Li and co‐workers [ 206 ] assembled trimetallic Co/Fe/Ni MOG in water. At a Co/Fe/Ni molar ratio of 5/1/4, the derived oxide exhibited a low overpotential of 244 mV at 10 mA cm −2 and a small Tafel slope of 55.4 mV dec −1 in an alkaline half‐cell.…”

Phytic Acid‐Based FeCo Bimetallic Metal‐Organic Gels for Electrocatalytic Oxygen Evolution Reaction

“…Taking advantage of chemical diversity and easy preparation, metal‐organic gels (MOGs) [31–37] attract growing attention as electrocatalysts in oxygen evolution reaction, [33,35] electrooxidation, [38,39] oxygen reduction reaction [32,40] and others [41] . Recently a new catalogue of MOGs have been shown to be synthesized simply from PA and a diversity of metal ions under mild conditions [42,43] .…”