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A rational design of bimetallic PdAu nanoflowers as efficient catalysts for methanol oxidation reaction 下载免费PDF全文
《中国物理 B》2021,30(5):56102-056102
Methanol fuel cells have been intensively developed as clean and high-efficiency energy conversion system due to their high efficiency and low emission of pollutants. Here, we developed a simple aqueous synthetic method to prepare bimetallic Pd Au nanoflowers catalysts for methanol oxidation reaction(MOR) in alkaline environment. Their composition can be directly tuned by changing the ratio between Pd and Au precursors. Compared with commercial Pd/C catalyst, all of the Pd Au nanoflowers catalysts show the enhanced catalytic activity and durability. In particular, the Pd Au nanoflowers specific activity reached 0.72 m A/cm2, which is 14 times that of commercial Pd/C catalyst. The superior MOR activity could be attributed to the unique porous structure and the shift of the d-band center of Pd. 相似文献
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Wu Tong Dr. Qi Shao Pengtang Wang Prof. Xiaoqing Huang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(29):7218-7224
The design and development of non-noble metal alternatives with superior performance and promising long-term stability that is comparable or even better than those of noble-metal-based catalysts is a significant challenge. Here, we report the thermal-induced phase engineering of non-noble-metal-based nanowires with superior electrochemical activity and stability for the methanol oxidation reaction (MOR) under alkaline conditions. The optimized Cu–Ni nanowires deliver an unprecedented mass activity of 425 mA mg−1, which is 4.3 times higher than that of the untreated one. Detailed catalytic investigations show that the enhanced performance is due to the large active area, the increased number of active sites (NiOOH), and fast methanol electrooxidation kinetics. In addition, the generated hollow feature in the nanowires provides a unique void space to release the volume expansion, where the activity can be maintained for 5 h without a distinct activity decay. The present work emphasizes the importance of precisely phase modulating of nanomaterials for the design of non-noble metal electrocatalysts towards the MOR, which opens up a new pathway for the design of cost-effective electrocatalysts with promising activity and long-term stability. 相似文献
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Inside Back Cover: Carbon Dioxide to Methanol: The Aqueous Catalytic Way at Room Temperature (Chem. Eur. J. 44/2016) 下载免费PDF全文
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Palladium‐Catalyzed Carbonylations of Aryl Bromides using Paraformaldehyde: Synthesis of Aldehydes and Esters 下载免费PDF全文
Dr. Kishore Natte Dr. Andreas Dumrath Dr. Helfried Neumann Prof. Dr. Matthias Beller 《Angewandte Chemie (International ed. in English)》2014,53(38):10090-10094
Carbonylation reactions represent useful tools for organic synthesis. However, the necessity to use gaseous carbon monoxide is a disadvantage for most organic chemists. To solve this problem, novel protocols have been developed for conducting palladium‐catalyzed reductive carbonylations of aryl bromides and alkoxycarbonylations using paraformaldehyde as an external CO source (CO gas free). Hence, aromatic aldehydes and esters were synthesized in moderate to good yields. 相似文献
48.
A practical heterogeneous palladium‐catalyzed carbonylative Suzuki coupling of aryl iodides with arylboronic acids under carbon monoxide gas‐free conditions has been developed using a bidentate phosphino‐functionalized magnetic nanoparticle‐immobilized palladium(II) complex as catalyst. Formic acid was utilized as the carbon monoxide source with dicyclohexylcarbodiimide as the activator, and a wide variety of biaryl ketones were generated in moderate to high yields. The new heterogeneous palladium catalyst can be prepared via a simple procedure and can easily be separated from a reaction mixture by simply applying an external magnet and recycled up to 10 times without any loss of activity. 相似文献
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Back Cover: Rhodium‐Catalyzed Ketone Methylation Using Methanol Under Mild Conditions: Formation of α‐Branched Products (Angew. Chem. Int. Ed. 3/2014) 下载免费PDF全文
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《Journal of Polymer Science.Polymer Physics》2018,56(7):558-575
Partially sulfonated poly(aryl ether sulfone) (PESS) was synthesized and methacrylated via reaction with glycidyl methacrylate (PESSGMA) and cross‐linked via radical polymerization with styrene and vinyl‐phosphonic acid (VPA). The chemical structures of the synthesized pre‐polymers were characterized via FTIR and 1H NMR spectroscopic methods and molecular weight was determined via GPC. Membranes of these polymers were prepared via solution casting method. The crosslinking of the PESS polymer reduced IEC, proton conductivity, swelling in water, and methanol permeability of the membranes while increasing the modulus and the glass transition temperature. However, the introduction of the VPA comonomer increased the proton conductivity while maintaining excellent resistance to methanol cross‐over, which was significantly higher as compared with both PESS and the commercial Nafion membranes. Membranes of PESSGMA copolymers incorporating VPA, exhibited proton conductivity values at 60 °C in the range of 16–32 mS cm−1 and methanol permeability values in the range of 6.52 × 10−9 – 1.92 × 10−8 cm2 s−1. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2018 , 56, 558–575 相似文献