Single-atom catalysis of CO oxidation using Pt1/FeOx
Single-atom catalysis of CO oxidation using Pt1/FeOx
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DOI：
10.1038/nchem.1095
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发表时间：
2011-08-01
期刊：
影响因子：
21.8
通讯作者：
Zhang, Tao
中科院分区：
文献类型：
--
作者：
Qiao, Botao;Wang, Aiqin;Zhang, Tao
铂基非均相催化剂对于许多重要的商业化学过程是至关重要的，但是它们的效率在每个金属原子的基础上是非常低的，因为仅使用表面活性位点原子。因此，具有单原子分散体的催化剂是高度期望的，以使原子效率最大化，但制造它们是具有挑战性的。在这里，我们报告的单原子催化剂的合成，仅由孤立的单个铂原子锚定到氧化铁纳米晶的表面。这种单原子催化剂具有极高的原子效率，并表现出优异的稳定性和高活性的CO氧化和CO在H-2中的优先氧化。密度泛函理论计算表明，高催化活性与带正电荷的高价Pt原子5d轨道的部分空位有关，这有助于降低CO的吸附能和CO氧化的活化能垒.
Platinum-based heterogeneous catalysts are critical to many important commercial chemical processes, but their efficiency is extremely low on a per metal atom basis, because only the surface active-site atoms are used. Catalysts with single-atom dispersions are thus highly desirable to maximize atom efficiency, but making them is challenging. Here we report the synthesis of a single-atom catalyst that consists of only isolated single Pt atoms anchored to the surfaces of iron oxide nanocrystallites. This single-atom catalyst has extremely high atom efficiency and shows excellent stability and high activity for both CO oxidation and preferential oxidation of CO in H-2. Density functional theory calculations show that the high catalytic activity correlates with the partially vacant 5d orbitals of the positively charged, high-valent Pt atoms, which help to reduce both the CO adsorption energy and the activation barriers for CO oxidation.