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151.
Metal cluster compounds are expected to be catalysts for new reactions because of synergistic effect of the metal atoms. In solid-state halide clusters and sulfide clusters, metal cluster frameworks are linked in two- or three-dimensions to form a cluster network. Halogen- or sulfur-deficient metal sites in an octahedral metal cluster framework are retained intact and act as catalytically active sites even at high temperatures of 400–700?°C. This review reports recent advances in the development of coordinatively unsaturated metal atoms on solid-state clusters with an octahedral metal framework and their application to organic catalytic reactions. 相似文献
152.
Electrocatalytic Oxidation of 5‐(Hydroxymethyl)furfural Using High‐Surface‐Area Nickel Boride 下载免费PDF全文
Dr. Stefan Barwe Jonas Weidner Steffen Cychy Dulce M. Morales Stefan Dieckhöfer Dennis Hiltrop Dr. Justus Masa Prof. Dr. Martin Muhler Prof. Dr. Wolfgang Schuhmann 《Angewandte Chemie (International ed. in English)》2018,57(35):11460-11464
The electrochemical oxidation of the biorefinery product 5‐(hydroxymethyl)furfural (HMF) to 2,5‐furandicarboxylic acid (FDCA), an important platform chemical for the polymer industry, is receiving increasing interest. FDCA‐based polymers such as polyethylene 2,5‐furandicarboxylate (PEF) are sustainable candidates for replacing polyethylene terephthalate (PET). Herein, we report the highly efficient electrocatalytic oxidation of HMF to FDCA, using Ni foam modified with high‐surface‐area nickel boride (NixB) as the electrode. Constant potential electrolysis in combination with HPLC revealed a high faradaic efficiency of close to 100 % towards the production of FDCA with a yield of 98.5 %. Operando electrochemistry coupled to ATR‐IR spectroscopy indicated that HMF is oxidized preferentially via 5‐hydroxymethyl‐2‐furancarboxylic acid rather than via 2,5‐diformylfuran, which is in agreement with HPLC results. This study not only reports a low‐cost active electrocatalyst material for the electrochemical oxidation of HMF to FDCA, but additionally provides insight into the reaction pathway. 相似文献
153.
Fan Lv Zhiquan Lang Kangning Zhao Prof. Liang Zhou Dr. Lyudmila Moskaleva Prof. Shaojun Guo Prof. Liqiang Mai 《Angewandte Chemie (International ed. in English)》2018,57(2):496-500
Proton adsorption on metallic catalysts is a prerequisite for efficient hydrogen evolution reaction (HER). However, tuning proton adsorption without perturbing metallicity remains a challenge. A Schottky catalyst based on metal–semiconductor junction principles is presented. With metallic MoB, the introduction of n‐type semiconductive g‐C3N4 induces a vigorous charge transfer across the MoB/g‐C3N4 Schottky junction, and increases the local electron density in MoB surface, confirmed by multiple spectroscopic techniques. This Schottky catalyst exhibits a superior HER activity with a low Tafel slope of 46 mV dec?1 and a high exchange current density of 17 μA cm?2, which is far better than that of pristine MoB. First‐principle calculations reveal that the Schottky contact dramatically lowers the kinetic barriers of both proton adsorption and reduction coordinates, therefore benefiting surface hydrogen generation. 相似文献
154.
David G. Churchill Jun Ho Shin Gerard Parkin 《Journal of chemical crystallography》2003,33(4):297-302
Photolysis of (CpBu
t)2MoH2 in benzene yields the molybdenocene derivative trans-[(CpBu
t)Mo(- ,5-C5H3But)H]2. An X-ray diffraction study demonstrate that the molybdenum centers of trans-[(CpBu
t)Mo(- , 5-C5H3But)H]2 are bridged by two , 5-C5H3But ligands, each one of which coordinates in a -manner to one molybdenum center and an 5-manner to the other, thereby resulting in a centrosymmetric dimer with a structural type that is different from that of [CpMo(- , 5-C5H4)]2 which possesses a Mo–Mo bond. 相似文献
155.
Kevin J. Coutinho Ron S. Dickson George A. Koutsantonis Brian W. Skelton Allan H. White Prof. Dr. 《无机化学与普通化学杂志》2008,634(4):669-674
Syntheses of the array of heterobimetallic complexes [(OC)3M(μ‐PPh2)2(μ‐O‐C(CHMe(CH2)2PPh2)RhL], M = Cr, Mo, W, L = tBuNC, are described, extending the previous study of the counterpart array for L = CO. A single crystal X‐ray structure determination is reported for the M = Mo adduct, enabling comparison with its previously reported L = CO counterpart, for which an improved redetermination is also reported. In the present complex the tBuNC ligand is found to be much more weakly bound (Rh‐C 2.026(5) Å) than the carbonyl group it displaces (Rh‐C 1.945(2) Å) with concomitant minor impact on the remainder of the rhodium ambience. 相似文献
156.
Pathik Maji 《Journal of organometallic chemistry》2008,693(10):1841-1849
A major challenge that must be met for an asymmetric intermolecular Pauson-Khand reaction is to be able to limit the possible positions on the metal complex for the organic partners. Toward this end, the synthesis of monometallic systems derived from M(CO)6 and two bidentate ligands, in which the number of possible coordination sites is reduced to two, has been investigated. 相似文献
157.
Taichi Mitsumoto Dr. Yuya Ashida Dr. Kazuya Arashiba Dr. Shogo Kuriyama Akihito Egi Prof. Dr. Hiromasa Tanaka Prof. Dr. Kazunari Yoshizawa Prof. Dr. Yoshiaki Nishibayashi 《Angewandte Chemie (International ed. in English)》2023,62(43):e202306631
We newly designed and prepared a novel molybdenum complex bearing a 4-[3,5-bis(trifluoromethyl)phenyl]pyridine-based PNP-type pincer ligand, based on the bond dissociation free energies (BDFEs) of the N−H bonds in molybdenum-imide complexes bearing various substituted pyridine-based PNP-type pincer ligands. The complex worked as an excellent catalyst toward ammonia formation from the reaction of an atmospheric pressure of dinitrogen with samarium diiodide as a reductant and water as a proton source under ambient reaction conditions, where up to 3580 equivalents of ammonia were formed based on the molybdenum atom of the catalyst. The catalytic activity was significantly improved by one order of magnitude larger than that observed when using the complex before modification. 相似文献
158.
Prof. Dr. Yuandong Xu Binyang Liu Chaoyang Dong Haoyang Feng Prof. Dr. Yajun Wei Prof. Dr. Xia Zhang 《欧洲无机化学杂志》2023,26(1):e202200569
Three-dimensional (3D) heterostructured molybdenum disulfide (MoS2) is used as base materials for aniline monomer in situ polymerization on its surface. It is found that the aniline addition has a remarkable effect on the energy storage of the final compounds due to the improvement of the conductivity and structure stability combined with the synergistic effect between the two types of species. The optimal compound of PANI@MoS2-150 not only shows a high capacitance value of 801.4 F ⋅ g−1 at a current density of 0.5 A ⋅ g−1 but also provides a high retention rate of 77.4 % after 10,000 cycles. The capacitance fading may be due to the increase of the internal resistance analyzed by EIS. Furthermore, a flexible symmetric supercapacitor based on PANI@MoS2-150 has also been fabricated and the specific capacitance reaches 105 F ⋅ g−1 at a current density of 1 A ⋅ g−1. Impressively, the capacitance retention is larger than 100 % undergoing 10,000 cycles. Besides, the highest energy density of 21 Wh ⋅ kg−1 was obtained. Additionally, the fabricated symmetric supercapacitor demonstrates excellent flexibility. 相似文献
159.
Molybdenum oxide (MoOx) is a well-studied transition-metal semiconductor material, and has a wider band gap than MoS2 which makes it become a promising versatile probe in a variety of fields, such as gas sensor, catalysis, energy storage ect. However, few MoOx nanomaterials possessing photoluminescence have been reported until now, not to mention the application as photoluminescent probes. Herein, a one-pot method is developed for facile synthesis of highly photoluminescent MoOx quantum dots (MoOx QDs) in which commercial molybdenum disulfide powder and hydrogen peroxide (H2O2) are involved as the precursor and oxidant, respectively. Compared with current synthesis methods, the proposed one has the advantages of rapid, one-pot, easily prepared, environment friendly as well as strong photoluminescence. The obtained MoOx QDs is further utilized as an efficient photoluminescent probe, and a new off-on sensor has been constructed for phosphate (Pi) determination in complicated lake water samples, attributed to the fact that the binding affinity of Eu3+ ions to the oxygen atoms from Pi is much higher than that from the surface of MoOx QDs. Under the optimal conditions, a good linear relationship was found between the enhanced photoluminescence intensity and Pi concentration in the range of 0.1–160.0 μM with the detection limit of 56 nM (3σ/k). The first application of the photoluminescent MoOx nanomaterials for ion photochemical sensing will open the gate of employing MoOx nanomaterials as versatile probes in a variety of fields, such as chemi-/bio-sensor, cell imaging, biomedical and so on. 相似文献
160.
建立了薄膜梯度扩散(DGT)- 硫氰酸钾(PT)分光光度法(DGT-PT法)富集测量水中痕量Mo (VI) 的分析方法。本研究先以聚季铵盐(PQAS)溶液为结合相的DGT技术 (PQAS DGT) 原位分离富集水中Mo (VI),再以PT分光光度法测定DGT结合相中Mo (VI)的含量,最后依据DGT方程计算水中Mo (VI)的浓度。DGT-PT法测得配制水中Mo ( VI) 的回收率为96.3% ~ 101.3%,相对标准偏差(RSD)为1.3% ~4.0%;测得工业废水中Mo (VI) 的浓度为27.13 ~ 121.79mg/L,加标回收率为96.0% ~ 101.6%。当采样时间为48h,PQAS DGT对水中Mo (VI) 富集近18倍,可显著降低分析方法的检测限,实现水中痕量Mo (VI) 的定量检测。 相似文献