| 项目编号: | 1511615
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| 项目名称: | UNS:High Surface Free Energy Anchoring of Bimetallic Core Shell Particles |
| 作者: | John Monnier
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| 承担单位: | University of South Carolina at Columbia
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| 批准年: | 2014
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| 开始日期: | 2015-08-15
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| 结束日期: | 2018-07-31
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| 资助金额: | USD471000
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| 资助来源: | US-NSF
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| 项目类别: | Continuing grant
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| 国家: | US
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| 语种: | 英语
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| 特色学科分类: | Engineering - Chemical, Bioengineering, Environmental, and Transport Systems
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| 英文关键词: | core
; surface free energy core material
; au
; bimetallic catalyst particle
; reaction condition
; core-shell
; proposal
; surface shell
; core material
; shell thickness
; research
; high temperature
; core particle size
; core component
; active surface
; bimetallic particle
; small core-shell particle
; core-shell catalyst
; surface energy shell material
; realistic high-temperature reaction environment
|
| 英文摘要: | Metallic catalysts for today's applications must be capable of stable operation at extreme conditions of feed compositions and temperatures. Thus, catalyst design and synthesis have become increasingly important to ensure catalyst particles which efficiently use expensive metals such as platinum group metals, and maintain an active surface at high temperatures and atypical feed compositions.The proposed work will create bimetallic catalyst particles dispersed on a carbon catalyst support that have improved resistance to particle coarsening under reaction conditions compared to the active metal component alone. The particle stabilization is achieved by depositing a surface shell of the active (gold, Au) catalyst on a core of a higher surface free energy core material (platinum (Pt), or various earth-abundant transition metals). The concept will be tested in the Au-catalyzed selective hydrochlorination of acetylene with gas-phase hydrochloric acid to produce vinyl chloride (an important intermediate in bulk chemical production). Preliminary work has shown dramatic stabilization of Au particles by depositing the Au on small Pt clusters prepared by atomic layer deposition. In this study, the Pt(core)-Au(shell) bimetallic particles will be further optimized and lower-cost earth-abundant copper (Cu), nickel (Ni), and cobalt (Co) will be evaluated as stabilizing core materials.
This is a hypothesis driven proposal based on the simple idea that a higher surface free energy core material in a small core-shell particle can stabilize a lower surface energy shell material that otherwise would sinter rapidly under reaction conditions. The PIs have already obtained data indicating the concept works for two-nanometer Pt(core) particles (prepared by strong electrostatic adsorption) surface-coated with Au (prepared by atomic layer deposition). The further work will compare homogeneous alloys to core-shell catalysts of the same nominal composition, and will also examine the effects of shell thickness and core particle size on acetylene hydrochlorination activity and durability. The potential of nano-scale multi-metallic particles for improved catalytic performance and selectivity is a growing area of interest in catalysis, as is understanding of the working composition and structure of such catalysts. This proposal takes important steps toward optimizing the structure of bimetallic catalyst particles under reaction conditions with an eye toward ensuring long-term catalyst stability in realistic high-temperature reaction environments.
Although much attention is being directed towards novel ways of creating supported catalysts containing active metal nano-clusters, few studies have gone beyond initial synthesis and testing to examine long-term stability under reaction conditions. Thus, the present proposal is a welcome addition to research in this area, with expected results that could impact a broad range of catalyst systems beyond the specific ones addressed here. In addition, the proposal offers a route to lower-cost catalysts based on sparing utilization of expensive precious, or noble, active metal components by utilizing core components that are low in cost such as Cu, Ni, and Co. The research will provide opportunities for both graduate and undergraduate students to participate in research directed towards industrial applications utilizing advanced synthesis techniques that can potentially enhance a broad range of catalytic processes. |
| 资源类型: | 项目
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| 标识符: | http://119.78.100.158/handle/2HF3EXSE/93745
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| Appears in Collections: | 影响、适应和脆弱性
气候减缓与适应
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| Recommended Citation: | |
John Monnier. UNS:High Surface Free Energy Anchoring of Bimetallic Core Shell Particles. 2014-01-01.
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