Assembly ofϵ‐Keggin Polyoxometalate from Molecular Crystal to Zeolitic Octahedral Metal Oxide

Abstract

Zeolitic octahedral metal oxides are inorganic crystalline microporous materials with adsorption and redox properties. New ɛ-Keggin nickel molybdate-based zeolitic octahedral metal oxides have been synthesized. 31 P NMR spectroscopy shows that reduction of Mo VI -based molybdates forms an ɛ-Keggin polyoxometalate that immediately transfers to the solid phase. Investigation of the formation process indicates that a low Ni concentration, insoluble reducing agent, and long synthesis time are the critical factors for obtaining the zeolite octahedral metal oxides rather than the ɛ-Keggin polyoxometalate molecule. The synthesized zeolitic nickel molybdate with Na + is used as the adsorbent, which effectively separates C 2 hydrocarbon mixtures.

A Zeolitic Octahedral Metal Oxide with Ultra‐Microporosity for Inverse CO2/C2H2Separation at High Temperature and Humidity

“…The cations of NH 4 ‐ZM and Na‐ZM were exchanged with Mg 2+ in aqueous solution at 333 K to obtain Mg 2+ ‐exchanged materials, denoted as Mg‐NH 4 ‐ZM and Mg‐Na‐ZM , respectively. Scanning electron microscopy (SEM) showed that the morphologies of the ϵ‐Keggin POM‐based ZOMOs were similar, and all of the materials had particles that were approximately 100 nm in diameter (Figure S1) [14a, 15–17] …”

“…ZOMOs based on ϵ‐Keggin POMs have shown high elemental diversity, and iso‐structural materials were synthesized. The linkers of these materials were altered by changing the linker sources in the syntheses; ZnCl 2 , [14a] CoCl 2 , [15] MnO, [14a] NiCl 2 ⋅6 H 2 O, [16] and Fe 3 O 4 [17] produced ZOMOs of ammonium zinc molybdate, ammonium cobalt molybdate, ammonium manganese molybdate, ammonium nickel molybdate, and ammonium iron molybdate, which are denoted as NH 4 ‐ZM , NH 4 ‐CM , NH 4 ‐MM , NH 4 ‐NM , and NH 4 ‐IM , respectively. Furthermore, the cation of NH 4 ‐ZM was also changed by changing the cation of the molybdate salt used in the syntheses [14b] .…”

POM-derived MoO3/CoMoO4mixed oxides directed by glucose for high-performance supercapacitors

“…19,20 The POMs can be used as the precursors for various multi-metallic oxides. [21][22][23] Meanwhile, a self-sacrificial template approach is a significant technique for the preparation of nanocomposites with a high specific area and extra active sites, which would lead to a higher specific capacity and better rate capability. [24][25][26] Carbon materials are widely utilized as sacrificial templates to assemble porous materials on account of convenient acquisition, regular morphology and easy removal.…”