当前位置：
X-MOL 学术
›
J. Phys. Chem. C
›
论文详情
Our official English website, www.x-mol.net, welcomes your
feedback! (Note: you will need to create a separate account there.)
Tuning the Electronic Properties of Single-Atom Pt Catalysts by Functionalization of the Carbon Support Material
The Journal of Physical Chemistry C ( IF 3.3 ) Pub Date : 2017-09-19 00:00:00 , DOI: 10.1021/acs.jpcc.7b05894 Mehdi Mahmoodinia 1 , Per-Olof Åstrand 1 , De Chen 2
The Journal of Physical Chemistry C ( IF 3.3 ) Pub Date : 2017-09-19 00:00:00 , DOI: 10.1021/acs.jpcc.7b05894 Mehdi Mahmoodinia 1 , Per-Olof Åstrand 1 , De Chen 2
Affiliation
|
When using support materials in heterogeneous catalysis, a fundamental understanding of the interactions between the catalyst and the support material is of critical importance. In this work, the stability, electronic structure, and catalytic activity of single-atom Pt catalysts on oxidized carbon support materials are investigated using first-principles calculations. The results are discussed based on both frontier–orbital hybridization and on a charge-transfer scheme. It is found that the strengthening of the Pt/C interactions by the carbon support with different oxygen concentrations is more due to charge transfer than frontier–orbital hybridization. In general, the larger the concentration of oxygen containg groups (OCGs) is and the closer they are to the Pt adatom, the stronger is the Pt binding energy to the carbon support. The dependence of the CO adsorption energy and CO vibrational stretching frequency on the concentration and the proximity of the OCGs to the Pt adatoms enables us to gauge quantitatively the effects of surface functionalization on the stability and catalytic activity of Pt catalysts. The change in the chemisorption energy of the CO molecule to the Pt adatom is discussed based on the position of the Pt d-band center, where it is found that it is shifted toward lower energy by increasing the concentration of OCGs. This downshift suppresses the coupling between the Pt d-band and the CO 2π* state, and consequently both the catalytic activity and the CO adsorption energy are reduced. Our results suggest that tailoring the carbon support by oxygen-containing groups could provide a route for improving the tolerance of Pt/C catalysts to CO poisoning.
中文翻译：
通过碳载体材料的功能化来调节单原子Pt催化剂的电子性能
当在非均相催化中使用载体材料时，对催化剂和载体材料之间相互作用的基本理解至关重要。在这项工作中，使用第一性原理计算研究了单原子Pt催化剂在氧化碳载体材料上的稳定性，电子结构和催化活性。基于边界-轨道杂交和电荷转移方案对结果进行了讨论。研究发现，不同氧浓度的碳载体对Pt / C相互作用的增强更多是由于电荷转移，而不是边界-轨道杂交。通常，含氧基团（OCG）的浓度越大，它们与Pt原子越近，Pt与碳载体的结合能越强。CO吸附能和CO振动拉伸频率对OCG的浓度和与Pt原子的接近程度的依赖性使我们能够定量评估表面功能化对Pt催化剂的稳定性和催化活性的影响。基于Pt的位置讨论了CO分子对Pt吸附原子的化学吸附能的变化d波段中心，发现它通过增加OCG的浓度而朝着较低的能量方向移动。该降档抑制了Pt d带与CO2π*状态之间的耦合，因此催化活性和CO吸附能均降低。我们的结果表明，通过含氧基团定制碳载体可以为提高Pt / C催化剂对CO中毒的耐受性提供一条途径。
更新日期：2017-09-19
中文翻译：
通过碳载体材料的功能化来调节单原子Pt催化剂的电子性能
当在非均相催化中使用载体材料时，对催化剂和载体材料之间相互作用的基本理解至关重要。在这项工作中，使用第一性原理计算研究了单原子Pt催化剂在氧化碳载体材料上的稳定性，电子结构和催化活性。基于边界-轨道杂交和电荷转移方案对结果进行了讨论。研究发现，不同氧浓度的碳载体对Pt / C相互作用的增强更多是由于电荷转移，而不是边界-轨道杂交。通常，含氧基团（OCG）的浓度越大，它们与Pt原子越近，Pt与碳载体的结合能越强。CO吸附能和CO振动拉伸频率对OCG的浓度和与Pt原子的接近程度的依赖性使我们能够定量评估表面功能化对Pt催化剂的稳定性和催化活性的影响。基于Pt的位置讨论了CO分子对Pt吸附原子的化学吸附能的变化d波段中心，发现它通过增加OCG的浓度而朝着较低的能量方向移动。该降档抑制了Pt d带与CO2π*状态之间的耦合，因此催化活性和CO吸附能均降低。我们的结果表明，通过含氧基团定制碳载体可以为提高Pt / C催化剂对CO中毒的耐受性提供一条途径。
京公网安备 11010802027423号