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通过静电吸引策略将具有高度分散性的原子精确纳米团簇[Pd3Cl(PPh2)2(PPh3)3]+(Pd3Cl)负载在介孔SBA-15棒上。结构明确的Pd3Cl/SBA-15催化剂在以水作为溶剂以及温和的反应条件下对催化Sonogashira碳-碳偶联反应展现了较好的催化性能以及循环性。在此基础上,我们研究了Pd3Cl团簇结构与性能之间的关系,并证实内核的Pdδ+(0<δ<2)与配体之间的协同效应是催化反应的关键。  相似文献   
2.
Integration of different active sites into metallic catalysts, which may impart new properties and functionalities, is desirable yet challenging. Herein, a novel dealloying strategy is demonstrated to decorate nickel–aluminum layered double hydroxide (NiAl–LDH) onto a Pt–Ni alloy surface. The incorporation of chemical etching of Pt–Ni alloy and in situ precipitation of LDH are studied by joint experimental and theoretical efforts. The initial Ni‐rich Pt–Ni octahedra transform by interior erosion into Pt3Ni nanoframes with enlarged surface areas. Furthermore, owing to the basic active sites of the decorated LDH together with the metallic sites of Pt3Ni, the resulting Pt–Ni nanoframe/NiAl–LDH composites exhibit excellent catalytic activity and selectivity in the dehydrogenation of benzylamine and hydrogenation of furfural.  相似文献   
3.
The activity and stability of Cu nanostructures strongly depend on their sizes, morphology and structures.Here we report the preparation of two-dimensional(2 D) Cu@Cu-BTC core-shell nanosheets(NSs). The thickness of the Cu NSs could be tuned to sub-10 nm through a mild etching process, in which the Cu-BTC in situ grow along with the oxidation on the surface of the Cu NSs. This unique strategy can also be extended to synthesize one-dimensional(1 D) Cu@Cu-BTC nanowires(NWs). Furthermore, the obtained Cu@Cu-BTC NSs could be applied as an effective material to the memory device with the write-onceread-many times(WORM) behavior and the high I_(ON)/I (OFF) ratio(2.7 × 10~3).  相似文献   
4.
An ordered mesh of palladium with a thickness of about 3 nm was synthesized by a solution‐based oxidative etching. The ultrathin palladium nanomeshes have an interconnected two‐dimensional network of densely arrayed, ultrathin quasi‐nanoribbons that form ordered open holes. The unique mesoporous structure and high specific surface area make these ultrathin Pd nanomeshes display superior catalytic performance for ethanol electrooxidation (mass activity of 5.40 Am g?1 and specific activity of 7.09 mA cm?2 at 0.8 V vs. RHE). Furthermore, the regular mesh structure can be applied to support other noble metals, such as platinum, which exhibits extremely high hydrogen evolution reaction (HER) activity and durability.  相似文献   
5.
The rational design of metal–organic frameworks (MOFs) with hollow features and tunable porosity at the nanoscale can enhance their intrinsic properties and stimulates increasing attentions. In this Communication, we demonstrate that methanol can affect the coordination mode of ZIF‐67 in the presence of Co2+ and induces a mild phase transformation under solvothermal conditions. By applying this transformation process to the ZIF‐67@ZIF‐8 core–shell structures, a well‐defined hollow Zn/Co ZIF rhombic dodecahedron can be obtained. The manufacturing of hollow MOFs enables us to prepare a noble metal@MOF yolk‐shell composite with controlled spatial distribution and morphology. The enhanced gas storage and porous confinement that originate from the hollow interior and coating of ZIF‐8 confers this unique catalyst with superior activity and selectivity toward the semi‐hydrogenation of acetylene.  相似文献   
6.
Engineering noble metal nanostructures at the atomic level can significantly optimize their electrocatalytic performance and remarkably reduce their usage. We report the synthesis of atomically dispersed Pt on screw-like Pd/Au nanowires by using ultrafine Pd nanowires as seeds. Au can selectively grow on the surface of Pd nanowires by an island growth pattern to fabricate surface defect sites to load atomically dispersed Pt, which can be confirmed by X-ray absorption fine structure measurements and aberration corrected HRTEM images. The nanowires with 2.74 at % Pt exhibit superior HER properties in acidic solution with an overpotential of 20.6 mV at 10 mA cm−2 and enhanced alkaline ORR performance with a mass activity over 15 times greater than the commercial platinum/carbon (Pt/C) catalysts.  相似文献   
7.
Bi2Se3 attracts intensive attention as a typical thermoelectric material and a promising topological insulator material. However, previously reported Bi2Se3 nanostructures are limited to nanoribbons and smooth nanoplates. Herein, we report the synthesis of spiral Bi2Se3 nanoplates and their screw‐dislocation‐driven (SDD) bidirectional growth process. Typical products showed a bipyramid‐like shape with two sets of centrosymmetric helical fringes on the top and bottom faces. Other evidence for the unique structure and growth mode include herringbone contours, spiral arms, and hollow cores. Through the manipulation of kinetic factors, including the precursor concentration, the pH value, and the amount of reductant, we were able to tune the supersaturation in the regime of SDD to layer‐by‐layer growth. Nanoplates with preliminary dislocations were discovered in samples with an appropriate supersaturation value and employed for investigation of the SDD growth process.  相似文献   
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