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哥搁浅了

金虫 (小有名气)

[求助] 【求助摘要翻译】相关专业:催化化学

Facile dissociation of reactants and weak binding of intermediates are key requirements for
efficient and selective catalysis. However, these two variables are intimately linked in a way
that does not generally allow the optimization of both properties simultaneously. By using
desorption measurements in combination with high-resolution scanning tunneling microscopy,
we show that individual, isolated Pd atoms in a Cu surface substantially lower the energy barrier
to both hydrogen uptake on and subsequent desorption from the Cu metal surface. This facile
hydrogen dissociation at Pd atom sites and weak binding to Cu allow for very selective
hydrogenation of styrene and acetylene as compared with pure Cu or Pd metal alone.
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zzbean

金虫 (正式写手)

【答案】应助回帖

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哥搁浅了(RXMCDM代发): 金币+4, 多谢应助! 2015-02-01 08:59:52
易与反应物分离以及与中间物间的弱联系为高效选择性催化剂的必备条件。但这两个变量间联系紧密,一般很难同时保证两者的优异性能。我们采用了脱附-高分辨STM(扫描隧道显微镜)联用技术对催化剂进行测试,发现Cu表面上的孤立Pd原子可充分减小Cu金属表面上的吸氢及随后氢脱附的能量位垒。此类催化剂中Pd原子位点处的氢较易分离,且与Cu间的联系较弱,因而较纯Cu或Pd金属对于苯乙烯及乙炔的加氢反应更具选择性。
2楼2015-01-04 06:24:03
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