A first principles study on the origin of the different selectivity for methanol steam reforming over Cu(111) and Pd(111); Cu(111)和Pd(111)上甲醇重整反应的不同选择性起源研究 | |
Gu XK(顾向奎) ; Li WX(李微雪) | |
2010-08-23 | |
会议名称 | 18th international vaccum congress |
会议日期 | 2010-8-23 |
会议地点 | 中国 |
其他题名 | cu(111)和pd(111)上甲醇重整反应的不同选择性起源研究 |
页码 | --/2 |
通讯作者 | 李微雪 |
中文摘要 | hydrogen is an attractive clean energy carrier as it is efficient, nonpolluting and inexhaustible for the future. despite that considerable attentions have been focused on methanol steam reforming (msr, ch3oh+h2o→co2+h2) for hydrogen production in proton-exchange membrane fuel cells (pemfc) applications in the past decades, the controversy remains in the reaction mechanisms [1]. among them, the selective conversion of methanol to carbon dioxide and hydrogen, instead of carbon monoxide, is crucial [2]. it was found experimentally that the selectivity of msr reaction on copper is markedly different from that on palladium [3]. copper catalyst, nearly completely transforming methanol to co2 and h2, exhibits higher selectivity than palladium catalyst, which predominantly converts methanol to co along with co2 and h2. the origin of the distinct selectivity between cu and pd is however unclear, and this prevents further optimization of msr catalysts for practical applications. to shed light on the reaction mechanism and selectivity of msr, we present in this talk a systematic density functional calculations on cu(111) and pd(111) surfaces. a number of intermediates, elementary reaction pathways and corresponding transition states are studied and identified, and valuable insights into the msr reaction and the origin of selectivity are illustrated. we find that the selectivity is controlled by the reactivity of formaldehyde (hcho). on cu(111), hcho tends to react with the coadsorbed hydroxyl to form hydroxymethoxy, followed by decomposition to co2 and hydrogen. whereas on pd(111), it is favorable to sequential dehydrogenation to co and hydrogen. finally, we represent a linear scaling relationship between the transition states energies and the final states energies for the elementary reactions involved in msr reaction, and discuss its implication with the computational design and optimization of the heterogeneous catalysts [4]. |
会议主办者 | 中国科学技术大学 |
学科主题 | 物理化学 |
语种 | 中文 |
内容类型 | 会议论文 |
源URL | [http://159.226.238.44/handle/321008/114136] |
专题 | 大连化学物理研究所_中国科学院大连化学物理研究所 |
推荐引用方式 GB/T 7714 | Gu XK,Li WX. A first principles study on the origin of the different selectivity for methanol steam reforming over Cu(111) and Pd(111), Cu(111)和Pd(111)上甲醇重整反应的不同选择性起源研究[C]. 见:18th international vaccum congress. 中国. 2010-8-23. |
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