Dalton Transactions

doi: 10.1039/D2DT90145Epmid: N/A

doi: 10.1039/D2DT90146Cpmid: N/A

Yang, Lida; Xu, Hui; He, Guangyu; Chen, Haiqun

doi: 10.1039/d2dt01757apmid: 36018245

Electrocatalytic water splitting has great research prospects in the production of green hydrogen energy, and electrocatalysts are the prerequisite. As widely employed efficient electrocatalysts, hollow nanostructures have attracted a lot of research attention due to their excellent catalytic activity and structural stability. Moreover, the abundant catalytically active sites and tunable morphology also make hollow nanomaterials promising electrocatalysts for water splitting. Despite these advantages, the industrial applications of these hollow nanocatalysts are impeded by limitations like the lack of effective synthesis methods and unclear formation mechanisms. Therefore, extensive efforts have been devoted to the development of efficient synthesis strategies to boost the development of more efficient hollow electrocatalysts, and great progress has been achieved in recent years. To gain a better understanding of the rapid development of hollow nanocatalysts for water splitting, we herein organize a review to summarize the recent synthetic methods and advantages of hollow materials with different dimensions. The specific advantages of hollow nanomaterials in electrocatalytic water splitting, such as abundant active sites, a stable structure, high mass transfer efficiency, and reduced aggregation of catalytic particles, are also summarized. Finally, the challenges and prospects of hollow nanostructures with multiple dimensions in electrocatalytic water splitting are further explored.

Devi, Bandhana; Koner, Rik Rani; Kurungot, Sreekumar

doi: 10.1039/d2dt01981gpmid: 36000481

The sustainable energy technology is in great demand due to the depletion and the risks associated with the use of fossil fuels. Various energy technologies like regenerative fuel cells, zincair batteries, and overall water-splitting devices have a huge scope in the growth of green energy. The efficiency of these devices is reliant upon the multifunctional electrocatalysts, which include both bifunctional and trifunctional electrocatalysts. Among the different categories of the materials used for such multifunctional electrocatalysis, metalorganic-frameworks (MOFs) occupy a very consolidated place because of their high surface area, porosity, and many other unique physicochemical properties. However, the use of MOFs for the trifunctional electrocatalytic applications is in the budding phase and needs to be explored more. Further, most of these MOF-based trifunctional electrocatalysts are derived by pyrolyzing MOFs at high temperatures. Therefore, there is a need to develop more conductive MOFs which can be directly utilized for the trifunctional applications. In this frontier article, we present the latest reports on the MOF-based materials for trifunctional applications. The material design strategies of the MOF-based materials for trifunctional electrocatalysis have been discussed. The progressive improvements made with MOFs in electrocatalytic applications have been provided with emphasis on the structural, active site and compositional requirements. Finally, the challenges and viewpoints on the future development of the MOF-based materials for trifunctional electrocatalysis have been provided.

Zmb, Greta G.; Mayr, Johannes; Sauer, Michael J.; Schlachta, Tim P.; Reich, Robert M.; Khn, Fritz E.

doi: 10.1039/d2dt02561bpmid: 36039702

The first macrocyclic and abnormally coordinating, mesoionic N-heterocyclic carbene iron complex has been synthesised and characterised via ESI-MS, EA, SC-XRD, CV, NMR and UV/Vis spectroscopy. 13C-NMR spectroscopy and CV measurements indicate a strong -donor ability of the carbene moieties, suggesting an efficient catalytic activity of the iron complex in oxidation reactions. Initial tests in the epoxidation of cis-cyclooctene as a model substrate confirm this assumption.

Zhu, Zhenhua; Liu, Shuting; Zhao, Chen; Li, Xiao-Lei; Mansikkamäki, Akseli; Tang, Jinkui

doi: 10.1039/d2dt02491hpmid: 36047750

The first oligopyrrolic Cu(II)-based metallocage featuring two antiferromagnetically coupled dimeric cupric tetracarboxylate units linked by a single molecule of water was assembled successfully using a nonlinear pyridine–pyrrolate ligand. Broken symmetry density functional theory (BS-DFT) calculations show that the exchange couplings between Cu(II) ions in the Cu2 unit and over the water bridge are −298 and −0.13 cm−1, respectively.

Su, Zhuizhui; Zhang, Bingxing; Cheng, Xiuyan; Xu, Mingzhao; Chen, Gang; Sha, Yufei; Wang, Yanyue; Hu, Jingyang; Duan, Ran; Zhang, Jianling

doi: 10.1039/d2dt01899cpmid: 36073182

Here, SnS2/polypyrrole (PPy) was synthesized, which shows high catalytic activity for the photocatalytic oxidation of benzylamine under mild conditions (at 25 C, in air and without adding an additional sacrificial reagent, redox mediator and photosensitizer).

Zakharov, Danila O.; Chernichenko, Konstantin; Sorochkina, Kristina; Repo, Timo; Zhivonitko, Vladimir V.

doi: 10.1039/d2dt02178apmid: 36073500

Parahydrogen-induced polarization is a nuclear spin hyperpolarization technique that can provide strongly enhanced NMR signals for catalytic hydrogenation reaction products and intermediates. Among other matters, this can be employed to study the mechanisms of the corresponding chemical transformations. Commonly, noble metal complexes are used for reactions with parahydrogen. Herein, we present a PHIP study of metal-free imine hydrogenations catalyzed by the ansa-aminoborane catalyst QCAT. We discuss the reaction mechanism by showing the pairwise nature of the initial hydrogen activation step that leads to the formation of the negative net nuclear spin polarization of N–H hydrogen in the QCAT-H2 intermediate, enabling the further transfer of parahydrogen-originating protons to the imine substrate with the accumulation of hyperpolarized amine products. Parahydrogen-induced polarization also demonstrates the reversibility of the catalytic cycle.

Morozkov, Gleb V.; Abel, Anton S.; Filatov, Mikhail A.; Nefedov, Sergei E.; Roznyatovsky, Vitaly A.; Cheprakov, Andrey V.; Mitrofanov, Alexander Yu.; Ziankou, Ilia S.; Averin, Alexei D.; Beletskaya, Irina P.; Michalak, Julien; Bucher, Christophe; Bonneviot, Laurent; Bessmertnykh-Lemeune, Alla

Edwards, Samuel J.; Bowron, Daniel T.; Baker, Robert J.

doi: 10.1039/d2dt02535cpmid: 36001015

The solution structure of 1.0 M Uranyl Chloride has been determined by the EPSR modelling of a combination of neutron scattering and EXAFS data. The experimental data show an equilibrium in solution between [UO2(H2O)5]2+ and [UO2Cl(H2O)4]+ with a stability constant of 0.23 ± 0.03 mol−1 dm−3. A much smaller fraction of the neutral [UO2Cl2(H2O)3] ion is also observed. The data also show, for the first time in solution, that the uranyl ion is a very poor hydrogen bond acceptor, but the coordinated waters show enhanced hydrogen bond ability compared to the bulk water.