The Experts below are selected from a list of 279 Experts worldwide ranked by ideXlab platform
Christoph Janiak - One of the best experts on this subject based on the ideXlab platform.
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confinement effects in zeolite confined Noble Metals
Angewandte Chemie, 2019Co-Authors: Xiao-yu Yang, Christoph JaniakAbstract:Confinement of Noble nanoMetals in a zeolite matrix is a promising way to special types of catalysts that show significant advantages in size control, site adjustment, and nano-architecture design. The beauty of zeolite-confined Noble Metals lies in their unique confinement effects on a molecular scale, and thus enables spatially confined catalysis akin to enzyme catalysis. In this Minireview, the confined synthesis strategies of zeolite-confined Noble Metals will be briefly discussed, showing the processes, advantages, features, and mechanisms. The confined catalysis carried on zeolite-confined Noble Metals will be summarized, and great emphasis will be paid to the confinement effects involving size, encapsulation, recognition, and synergy. Great progress of atomic sites in the size effect, supercage stabilization in the encapsulation effect, site adsorption in the recognition effect, and cascade reaction in the synergy effect are highlighted. This Minireview is concluded with challenges and opportunities in terms of the synthesis of zeolite-confined Noble Metals and their applications to design multifunctional catalysts with high catalytic activity, selectivity, and stability.
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Confinement Effects in Zeolite‐Confined Noble Metals
Angewandte Chemie (International ed. in English), 2019Co-Authors: Xiao-yu Yang, Christoph JaniakAbstract:Confinement of Noble nanoMetals in a zeolite matrix is a promising way to special types of catalysts that show significant advantages in size control, site adjustment, and nano-architecture design. The beauty of zeolite-confined Noble Metals lies in their unique confinement effects on a molecular scale, and thus enables spatially confined catalysis akin to enzyme catalysis. In this Minireview, the confined synthesis strategies of zeolite-confined Noble Metals will be briefly discussed, showing the processes, advantages, features, and mechanisms. The confined catalysis carried on zeolite-confined Noble Metals will be summarized, and great emphasis will be paid to the confinement effects involving size, encapsulation, recognition, and synergy. Great progress of atomic sites in the size effect, supercage stabilization in the encapsulation effect, site adsorption in the recognition effect, and cascade reaction in the synergy effect are highlighted. This Minireview is concluded with challenges and opportunities in terms of the synthesis of zeolite-confined Noble Metals and their applications to design multifunctional catalysts with high catalytic activity, selectivity, and stability.
Xiao-yu Yang - One of the best experts on this subject based on the ideXlab platform.
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confinement effects in zeolite confined Noble Metals
Angewandte Chemie, 2019Co-Authors: Xiao-yu Yang, Christoph JaniakAbstract:Confinement of Noble nanoMetals in a zeolite matrix is a promising way to special types of catalysts that show significant advantages in size control, site adjustment, and nano-architecture design. The beauty of zeolite-confined Noble Metals lies in their unique confinement effects on a molecular scale, and thus enables spatially confined catalysis akin to enzyme catalysis. In this Minireview, the confined synthesis strategies of zeolite-confined Noble Metals will be briefly discussed, showing the processes, advantages, features, and mechanisms. The confined catalysis carried on zeolite-confined Noble Metals will be summarized, and great emphasis will be paid to the confinement effects involving size, encapsulation, recognition, and synergy. Great progress of atomic sites in the size effect, supercage stabilization in the encapsulation effect, site adsorption in the recognition effect, and cascade reaction in the synergy effect are highlighted. This Minireview is concluded with challenges and opportunities in terms of the synthesis of zeolite-confined Noble Metals and their applications to design multifunctional catalysts with high catalytic activity, selectivity, and stability.
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Confinement Effects in Zeolite‐Confined Noble Metals
Angewandte Chemie (International ed. in English), 2019Co-Authors: Xiao-yu Yang, Christoph JaniakAbstract:Confinement of Noble nanoMetals in a zeolite matrix is a promising way to special types of catalysts that show significant advantages in size control, site adjustment, and nano-architecture design. The beauty of zeolite-confined Noble Metals lies in their unique confinement effects on a molecular scale, and thus enables spatially confined catalysis akin to enzyme catalysis. In this Minireview, the confined synthesis strategies of zeolite-confined Noble Metals will be briefly discussed, showing the processes, advantages, features, and mechanisms. The confined catalysis carried on zeolite-confined Noble Metals will be summarized, and great emphasis will be paid to the confinement effects involving size, encapsulation, recognition, and synergy. Great progress of atomic sites in the size effect, supercage stabilization in the encapsulation effect, site adsorption in the recognition effect, and cascade reaction in the synergy effect are highlighted. This Minireview is concluded with challenges and opportunities in terms of the synthesis of zeolite-confined Noble Metals and their applications to design multifunctional catalysts with high catalytic activity, selectivity, and stability.
Keiichi Tomishige - One of the best experts on this subject based on the ideXlab platform.
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methane reforming to synthesis gas over ni catalysts modified with Noble Metals
Applied Catalysis A-general, 2011Co-Authors: Yoshinao Nakagawa, Keiichi TomishigeAbstract:Abstract Nickel is an effective component for the steam reforming of methane in terms of the catalytic activity and the catalyst cost. When Ni catalysts are applied to dry reforming, oxidative reforming, and catalytic partial oxidation, it is necessary to add the properties of high resistance to oxidation, hot spot formation, and coke deposition, to the Ni catalysts. An efficient method for giving these properties while considering the catalyst cost is the modification of Ni metal particles with small amounts of Noble Metals. An important point is that preparation methods can affect the structure of Noble metal–Ni bimetallic particles, which is connected to the catalytic performances. The additive effects of Noble Metals on the catalytic performances are summarized in terms of activity, suppression of Ni oxidation, carbon formation, self-activation, and sustainability in the daily startup and shutdown operations.
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catalytic performance of ni ceo2 al2o3 modified with Noble Metals in steam gasification of biomass
Catalysis Today, 2008Co-Authors: Jin Nishikawa, Kazuya Nakamura, Mohammad Asadullah, Tomohisa Miyazawa, Kimio Kunimori, Keiichi TomishigeAbstract:Abstract In the steam gasification of biomass, the additive effect of Noble Metals such as Pt, Pd, Rh and Ru to the Ni/CeO2/Al2O3 catalyst was investigated. Among these Noble Metals, the addition of Pt was most effective even when the loading amount of added Pt was as small as 0.01 wt.%. In addition, the catalyst characterization suggests the formation of the Pt–Ni alloy over the Pt/Ni/CeO2/Al2O3.
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additive effect of Noble Metals on nio mgo solid solution in oxidative steam reforming of methane under atmospheric and pressurized conditions
Applied Catalysis A-general, 2006Co-Authors: Mohammad Nurunnabi, Kimio Kunimori, Yuya Mukainakano, Shigeru Kado, Kimihito Suzuki, Kenichiro Fujimoto, Keiichi TomishigeAbstract:Abstract The effect of Noble Metals (M = Rh, Pt and Pd) added to NiO-MgO solid solution catalyst on catalytic activity and carbon deposition was investigated in oxidative steam reforming of methane under atmospheric and pressurized conditions. The Noble metal addition enhanced methane conversion at low W / F condition, such as 0.13 g h mol −1 , and the promoting effect was easily observed even for a small amount of addition, such as 0.035% Rh. This Noble metal addition can maintain Ni species in a reduced state and it can enhance the methane activation ability and catalyst reducibility. Under pressurized conditions, it was found that the addition of Rh and Pt decreased carbon formation almost completely on Ni 0.2 Mg 0.8 O. The catalyst characterization suggests that Noble Metals–Ni alloy particles with the surface segregation of Noble Metals are formed on M/Ni 0.2 Mg 0.8 O. This is related to high resistance to deactivation due to oxidation and carbon formation.
Jung A. Hong - One of the best experts on this subject based on the ideXlab platform.
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Surface Spectroscopic Analysis of TiO_2 and ZnO Nanoparticles Doped with Noble Metals
Topics in Catalysis, 2018Co-Authors: Jung A. HongAbstract:Nanoparticles (NPs) of the well-known photocatalysts TiO_2 and ZnO each doped with Noble Metals (NM = Au, Pd, or Pt) were synthesized by applying a thermosynthetic method, and the catalytic activities of the resulting six samples were compared. After characterizing them by using high-resolution photoemission spectroscopy (HRPES), we evaluated the catalytic effects of the samples the oxidation of 4-aminothiophenol (4-ATP) by using HRPES under UV illumination and on the oxidation of 4-ATP in aqueous solution by taking electrochemistry measurements. In addition, we determined the rates of conversion of CO to CO_2 in the presence of these catalysts by using a residual gas analyzer under an ultra-high vacuum condition. As a result, we found a good positive correlation between the numbers of defect structures induced by the doped Noble Metals and the catalytic activity, and showed that Pd-TiO_2 and Pt-ZnO NPs can act as efficient catalysts due to their relatively large number of defect structures and corresponding oxygen vacancies. Graphical Abstract
Yu S Kononov - One of the best experts on this subject based on the ideXlab platform.
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recovery of Noble Metals from refractory sulfide black shale ores
Hydrometallurgy, 2014Co-Authors: O N Kononova, V V Patrushev, Yu S KononovAbstract:Abstract The processing of refractory sulfide black-shale ores and concentrates from the Sukhoy Log deposit containing gold, silver and platinum group Metals (palladium and platinum) was investigated. The Noble Metals were leached both under atmospheric pressure and at 700 kPa at 200 °C in an autoclave. It was found that the preferred leaching method is the chlorination of the ore in HCl/NaCL solutions in the presence of MnO2. The sorption recovery of Noble Metals on Purolite anion exchangers and carbon adsorbent Calgon GRC-22 was carried out from solution with the following initial concentrations of Noble Metals (in mg/L): Au — 25; Pt — 5; Pd — 5; and Ag — 10 in the presence of 1 M FeCl3, 0.1 М CuCl2, 1 M NaCl and 1 М HCl. It was shown that the chloride complexes of Noble Metals can be effectively adsorbed from this solution. Then, the selective elution of Noble Metals from anion exchangers Purolite A170 and Purolite S992 by means of different complex-forming reagents was studied. The best elution results were obtained with Na2SO3 + NaNO2 and thiourea solutions.