POM@ZIF Derived Mixed Metal Oxide Catalysts for Sustained Electrocatalytic Oxygen Evolution

Abstract

The design of efficient and stable oxygen evolution reaction (OER) catalysts based on noble‐metal‐free materials is crucial for energy conversion and storage. In this work, it was demonstrated how polyoxometalate (POM)‐doped ZIF‐67 can be converted into a stable oxygen evolution electrocatalyst by chemical etching, cation exchange, and thermal annealing steps. Characterization by X‐ray photoelectron spectroscopy, transmission electron microscopy, energy‐dispersive X‐ray spectroscopy and Raman spectroscopy indicate that POM‐doped ZIF‐67 derived carbon‐supported metal oxides were synthesized. The resulting composite shows structural and compositional advantages which lead to low overpotential (306 mV at j=10 mA ⋅ cm−2) and long‐term stability under harsh OER conditions (1.0 M aqueous KOH).

Stabilization and activation of polyoxometalate over poly(vinyl butylimidazolium) cations towards electrocatalytic water oxidation in alkaline media

“…have shown the heterogenization and activation of Keggin POMs {[Co II W 12 O 40 ] 6− (CoW 12 ) and [Bi(OH 2 ) 2 SiW 11 O 39 ] 5− } towards the OER by encapsulating the POM in the cavity of ZIF-8 (zeolitic imidazolate framework), 16,17 which turns into an efficient OER electrocatalyst at neutral pH. To the best of our knowledge, there are no reports where POMs have been used in 1 M KOH (except our previous work 15 and a just appeared report with PW 12 @ZIF 18 ). However, Streb et al .…”

Recent research progress on polyoxometalate-based electrocatalysts in energy generation

“…Zhao et al synthesized carbon-supported metal oxides doped with PW 12 , namely PW 12 @amZIFs, via a series of chemical etching, cation exchange and thermal annealing steps using amorphous ZIF-67 as the precursor. 141 The synergistic effect of POMs and ZIF-67 resulted in an enhanced electrocatalytic OER performance. The resulting composite material exhibited a superior structure and composition, leading to a low overpotential (306 mV, j = 10 mA cm −2 ) under OER conditions in 1.0 M KOH aqueous solution.…”

Decaniobate: The Fruit Fly of Niobium Polyoxometalate Chemistry

“…Applications exploiting rich redox behavior, supramolecular assembly, interactions with biomolecules, and POMs as inorganic ligands were summarized in a 1998 Chemical Reviews special issue . Currently, these applications continue to grow, with a focus on emergent societal issues of clean energy production, , energy storage, − and health sciences . Concurrently in the 20th century, Nb/Ta POM chemistry was largely limited to the Lindqvist ion (Nb 6 ) and the substitution of Nb into W-POM clusters.…”