LiNH2 is of interest to several aspects of energy storage such as reversible hydrogen storage, battery technology, catalysis, and ammonia capture/storage. We investigated the impact of nanoconfinement in carbon scaffolds on the hydrogen and ammonia release properties of LiNH2 and its catalytic activity in NH3 decomposition. Ammonia release from macrocrystalline LiNH2 begins at 350 °C, while confined LiNH2 releases ammonia from below 100 °C under helium flow. This ammonia release consisted of 30.5 wt % ammonia in the first cycle and was found to be partially reversible. Above 300 °C, hydrogen is also released due to an irreversible reaction between LiNH2 and the carbon support to form Li2NCN. Ni-doped LiNH2/C nanocomposites were active in the catalytic decomposition of ammonia into N2 and H2 with 53% conversion at 400 °C and a gas hourly space velocity of 13000 h–1. This is comparable to the performance of a commercial-type Ru-based catalyst where 79% conversion is observed under the same conditions. This work demonstrates that nanoconfinement is effective for improving the functionality of LiNH2. The versatility of this system offers promise in a number of different areas including hydrogen/ammonia storage and ammonia decomposition catalysis.

Interactions between the protein Hen Egg White Lysozyme (HEWL) and three different hybrid Anderson-Evans polyoxometalate clusters – AE−NH2 (-[MnMo6O18{(OCH2)3CNH2}2]3−), AE−CH3 (-MnMo6O18{(OCH2)3CCH3}2]3−) and AE-Biot (-[MnMo6O18{(OCH2)3CNHCOC9H15N2OS}2]3−) – were studied via tryptophan fluorescence...

Understanding the stability and speciation of metal-oxo clusters in solution is essential for many of their applications in different areas. In particular, hybrid organic–inorganic polyoxometalates (HPOMs) have been attracting increasing attention as they combine the complementary properties of organic ligands and metal–oxygen nanoclusters. Nevertheless, the speciation and solution behavior of HPOMs have been scarcely investigated. Hence, in this work, a series of HPOMs based on the archetypical Anderson–Evans structure, δ-[MnMo6O18{(OCH2)3C–R}2]3–, with different functional groups (R = −NH2, −CH3, −NHCOCH2Cl, −NCH­(2-C5H4N) {pyridine; −Pyr}, and −NHCOC9H15N2OS {biotin; −Biot}) and countercations (tetrabutylammonium {TBA}, Li, Na, and K) were synthesized, and their solution behavior was studied in detail. In aqueous solutions, decomposition of HPOMs into the free organic ligand, [MoO4]2–, and free Mn3+ was observed over time and was shown to be highly dependent on the pH, temperature, and nature of the ligand functional group but largely independent of ionic strength or the nature of the countercation. Furthermore, hydrolysis of the amide and imine bonds often present in postfunctionalized HPOMs was also observed. Hence, HPOMs were shown to exhibit highly dynamic behavior in solution, which needs to be carefully considered when designing HPOMs, particularly for biological applications.

Hybrid structures incorporating different organic and inorganic constituents are emerging as a very promising class of materials since they synergistically combine the complementary and diverse properties of the individual components....

The specific interactions of anionic metal-oxo clusters, known as polyoxometalates (POMs), with proteins can be leveraged for a wide range of analytical and biomedical applications. For example, POMs have been developed as selective catalysts that can induce protein modifications and have also been shown to facilitate protein crystallization, both of which are instrumental in the structural characterization of proteins. POMs can also be used for selective protein separation and enzyme inhibition, which makes them promising therapeutic agents. Hence, understanding POM-protein interactions is essential for the development of POM-based materials and their implementation in several fields. In this Review we summarize in detail the key insights that have been gained so far on POM-protein interactions. Emphasis is also given to hybrid POMs functionalized with organic ligands to prompt further research in this direction owing to the promising recent results on tuning POM-protein interactions through POM functionalization.