铁电极化调控CO在Pt表面的吸附 The CO Absorption on Pt Film Tuned by Ferroelectric Polarization

基于密度泛函理论的第一性原理，以BaTiO3和PbTiO3两种典型的铁电材料为例，我们探讨了铁电极化对CO在Pt薄膜表面吸附的影响。计算结果表明当极化方向为正时，CO在Pt/PbO/PbTiO3表面顶位的吸附能为−2.53 eV，而当极化方向反向时，CO的吸附能变为−1.39 eV。这表明铁电薄膜的铁电极化可有效调控CO在Pt表面的吸附。这种调控主要是由于极化所诱导的界面电场有效地改变了CO的4σ、1π、5σ轨道与Pt5d轨道之间的成键耦合。我们的研究为寻找抑制质子交换膜“CO中毒”的催化材料提供了新的方法。 We investigated the CO absorption on Pt film tuned by ferroelectric polarization of BaTiO3 and PbTiO3. Our results have demonstrated that the adsorption properties can be dramatically mod-ulated by the ferroelectric polarization. Especially, we found that the chemisorption energy are −2.53 eV with positive ferroelectric polarization for CO adsorbed on the top site of Pt/PbO/PbTiO3 while the chemisorptions energy reduce to −1.39 eV with inversion of the polarization direction. It is found that the coupling strength for the 4σ, 1π, 5σ orbital and 5d orbital of Pt can be tuned by the interfacial electric filed induced by the polarization of ferroelectric film. Our studies provide new approach for carbon monoxide poisoning resistant in proton exchange membrane catalytic material.

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