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首页> 外文期刊>The Journal of Chemical Physics >Modulating the reactivity of Ni-containing Pt(111)-skin catalysts by density functional theory calculations
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Modulating the reactivity of Ni-containing Pt(111)-skin catalysts by density functional theory calculations

机译：通过密度泛函理论计算来调节含镍Pt（111）-皮催化剂的反应性

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摘要

We present here a first principles density functional theory investigation of the reactivity of Pt(111)-skin catalysts, which are varied from surface alloys with Ni to bulk PtxNi1-x (x=0.25,0.50,0.75) alloys. Molecule (CO, O, and H) adsorption and oxidation of CO+O and H+O reactions were studied and analyzed in detail. Independent of the adsorbates, the interaction between adsorbates and substrates becomes weakened with increase in Ni, due to the downshift of d-band center of surface Pt atoms. Moreover, activation barriers of CO and H oxidation toward atomic oxygen gradually decrease. In term of CO preferential oxidation (PROX) in excess of hydrogen, it turns out that the overall reactivity and selectivity rely on the optimum of various elementary steps involved such as competitive molecular (dissociative) adsorption and oxidation reaction. The present calculations show that Pt3Ni(111) with Pt overlayer is an optimum catalyst for CO PROX in excess of hydrogen. (c) 2008 American Institute of Physics.
机译：我们在这里介绍了Pt（111）-皮肤催化剂反应性的第一原理密度泛函理论研究，该催化剂从具有Ni的表面合金到块状PtxNi1-x（x = 0.25,0.50,0.75）合金不等。研究和分析了CO + O和H + O反应的分子（CO，O和H）吸附和氧化。与吸附物无关，由于表面Pt原子的d带中心向下移动，吸附物与底物之间的相互作用随着Ni的增加而减弱。而且，CO和H向原子氧的氧化的激活势垒逐渐降低。就过量氢气中的CO优先氧化（PROX）而言，事实证明总体反应性和选择性取决于所涉及的各种基本步骤（例如竞争性分子（解离）吸附和氧化反应）的最佳状态。目前的计算表明，具有Pt覆盖层的Pt3Ni（111）是氢气中CO PROX的最佳催化剂。 （c）2008年美国物理研究所。

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