共查询到20条相似文献,搜索用时 31 毫秒
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Dr. Evgeny Naranov 《ChemCatChem》2024,16(9):e202301268
The noble metals are widely used in heterogeneous catalysis and automobile industry. The limited natural sources and high cost of noble metals dictates improving the efficiency of modern industry. This review considers the applications of noble metal oxide as potential solutions to the sustainability issues, including biomass conversion, CO2 capture and conversion, green fuel production, etc. Noble metal oxides with their different compositions (monometallic and bimetallic) and structures exhibit a wide range of properties in heterogeneous catalysis. Although platinum metals in an oxidized form may not be the most common choice in hydroprocesses; recently, there have been studies indicating that they were highly active and selective catalysts in hydrogenation and hydrogenolysis. This review outlines the most established noble metal oxide catalysts used in hydrogenation catalysis and shed the light on the relation of noble metal oxide species to catalyst selectivity based on state-of-the-art techniques. Finally, the perspectives on the application of noble metal oxide catalysts to produce value-added chemicals are discussed. 相似文献
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贵金属助剂促进的费-托合成用钴基催化剂具有高活性和长链烃(C5+)选择性优越等特点,被广泛应用于由合成气制清洁燃料的合成反应中。 本文重点讨论了贵金属助剂对活性钴物种的结构(还原度、分散度、双金属颗粒或合金的构成), 钴基催化剂稳定性以及其对费-托合成的反应速率和产物选择性的影响规律。 相似文献
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Syngas Production by Methane Reforming with Carbon Dioxide on Noble Metal Catalysts 总被引:2,自引:2,他引:2
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M. Rezaei S. M. Alavi S. Sahebdelfar Zi-Feng Yan 《天然气化学杂志》2006,15(4):327-334
A series of noble metal catalysts (Ru, Rh, Ir, Pt, and Pd) supported on alumina-stabilized magnesia (Spinel) were used to produce syngas by methane reforming with carbon dioxide. The synthesized catalysts were characterized using BET, TPR, TPO, TPH, and H2S chemisorption techniques. The activity results showed high activity and stability for the Ru and Rh catalysts. The TPO and TPH analyses indicated that the main reason for lower activity and stability of the Pd catalyst was the formation of the less reactive deposited carbon and sintering of the catalyst. 相似文献
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Dr. Jingjie Ge Dr. Zhijun Li Prof. Xun Hong Prof. Yadong Li 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(20):5113-5127
Core–shell noble metal catalysts have gained significant attention in the past few decades, as they not only reduce the use of noble metals effectively but also exhibit unique properties derived from the synergistic effect between core and shell metals. In particular, regulating the surface structure of shells to maximize the atomic utilization efficiency of noble metals is critically important. Controlling the shell thickness of noble metal catalysts at the atomic level as an efficient approach to realize this goal has been attracting growing attention; this approach involves the formation of ultrathin shells (typically 2–6 atomic layers), monolayers, or even atomically dispersed noble metals embedded in the host metal. These strategies drive the core/support metals to improve the number of active sites and the intrinsic activity of the deposited noble metals remarkably, meanwhile minimizing the usage of noble metals. Herein, recent advances regarding atomic control of the core–shell noble metal catalysts is reviewed, with focus on the surface regulation. First, synthesis methods and surface structures are summarized, and then catalytic applications of these architectures are highlighted. 相似文献
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Deep hydrodesulfurization (HDS) of sterically hindered sulfur compounds in gas oils will require enhanced hydrogenation activity to hydrogenate the aromatic rings of the sulfur compounds. Although H2S is known to inhibit the direct HDS route for most of the sulfided catalysts, its promotion to the hydrogenation and subsequent HDS was newly observed for unsupported MoS2. This promotion suggests that ultra deep HDS over sulfide catalysts can be achieved along with high metal loading, minimal support-metal interactions and optimal dependence on the Ni species. On the other hand, the strong hydrogenation activity of sulfur-tolerant noble metal catalysts suggests that ultra deep HDS as well as deep aromatics saturation can be achieved. This paper discusses recent catalytic approaches for ultra deep HDS using conventional sulfide catalysts and/or noble metal catalysts, such as the newly developed Pd-Pt/Yb-USY zeolite catalyst. 相似文献
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为有效提高负载型催化剂中贵金属的原子利用效率,贵金属单原子催化剂逐渐成为一个研究热点和前沿课题.我们针对单原子催化剂在催化氧化领域中的应用,综述了几种贵金属单原子催化剂的典型制备方法,包括原子层沉积法、湿法化学法、光化学辅助法、热解法等,并讨论了上述方法的优缺点.此外,对比传统贵金属负载型催化剂,我们重点讨论了贵金属基单原子催化剂在CO催化氧化、挥发性有机化合物(VOCs)催化氧化、催化机理等催化氧化过程中的最新研究进展,尤其是贵金属基单原子催化剂在低温低浓度催化氧化过程中表现出的优异催化活性、抗水性和抗毒性,表明该类催化剂具备极大的工业应用潜力.最后,进一步从大规模工业应用角度探讨了单原子催化剂目前面临的挑战和可能的解决办法,期望可以为应用于催化氧化过程的高效、稳定的单原子催化剂的设计提供思路. 相似文献
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将多孔硅浸入含贵金属盐的HF溶液20 s, 制备了Ag, Au, Pd和Pt的沉积层. AFM形貌显示, 这4种贵金属都能在多孔硅上直接沉积, 但Pt的沉积量比其他3种少. SEM图及能谱(Energy dispersive X-ray spectrometer, EDS)分析显示, 沉积层优先生长在孔边上, 孔边上的沉积量约是孔底的4.6倍. 电化学方法分析显示, Pd和Pt, Ag和Au的沉积层分别具有类似的开路电位和交流阻抗特性, 其中Pd层的溶出电流比其他3种大1个数量级, 而阻抗比其他小1个数量级, 说明Pd层与硅基底的结合程度好, 结合界面导电性好. 相似文献
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Coating films containing Au, Ag, Pt and Pd metal colloids have been prepared by sol-gel processing. It is shown that for oxide films the temperature where the metal particles are precipitated by heating in air depends on metal species: 200°C for Au, 600°C for Ag, 800°C for Pt and 1000°C for Pd. The use of reducing atmosphere lowers the temperature for formation of noble metal colloids. This procedure can be used for direct formation of metal colloids from metal ions in the film as well as reduction of oxide particles to metal particles in the film. For an organic-inorganic matrix, noble metal colloids are precipitated by thermal reduction or photo-reduction. Thermal reduction occurs as a result of reduction by decomposing organic matter. Photo-reduction occurs as a result of UV irradiation. 相似文献
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NO Reduction Over Noble Metal Ionic Catalysts 总被引:1,自引:0,他引:1
In last 40 years, catalysis for NO
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removal from exhaust gas has received much attention to achieve pollution free environment. CeO2 has been found to play a major role in the area of exhaust catalysis due to its unique redox properties. In last several
years, we have been exploring an entirely new approach of dispersing noble metal ions in CeO2 and TiO2 for redox catalysis. We have extensively studied Ce1−x
M
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O2−δ (M = Pd, Pt, Rh), Ce1−x−y
A
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M
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O2−δ (A = Ti, Zr, Sn, Fe; M = Pd, Pt) and Ti1−x
M
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O2−δ (M = Pd, Pt, Rh, Ru) catalysts for exhaust catalysis especially NO reduction and CO oxidation, structure–property relation
and mechanism of catalytic reactions. In these catalysts, lower valent noble metal ion substitution in CeO2 and TiO2 creates noble metal ionic sites and oxide ion vacancy. NO gets molecularly adsorbed on noble metal ion site and dissociatively
adsorbed on oxide ion vacancy site. Dissociative chemisorption of NO on oxide ion vacancy leads to preferential conversion
of NO to N2 instead of N2O over these catalysts. It has been demonstrated that these new generation noble metal ionic catalysts (NMIC) are much more
catalytically active than conventional nano crystalline noble metal catalysts especially for NO reduction. 相似文献