High-entropy alloyed single-atom Pt for methanol oxidation electrocatalysis
Mingda Liu, Zhichao Zhang, Chenyu Li, Sen Jin, Kunlei Zhu, Shoushan Fan, Jia Li, Kai Liu
Abstract
The methanol oxidation reaction is the bottleneck for direct methanol fuel cells. Unfortunately, the state-of-the-art Pt-based catalysts suffer heavily from the CO poisoning problem. Isolating Pt atoms in a material can avoid CO poisoning. However, single-atom Pt catalysts alone are inert towards methanol oxidation reaction. Here, we report high-entropy alloyed single-atom Pt catalysts, in which single-atom Pt sites are alloyed with non-noble elements in a high-entropy structure. This catalyst not only possesses active Pt sites but also inherits the ability of single-atom Pt to resist CO poisoning. Consequently, the catalyst shows a notable mass activity of 35.3 A mg−1 at only 2.3 at% Pt and maintains high activity even after operation for 180,000 s. Both experimental and theoretical results reveal that the high-entropy structure induces a synergistic effect, wherein the elements coordinated around single-atom Pt sites effectively remove adsorbed CO from Pt. This mechanism facilitates the key reaction steps of methanol oxidation reaction and avoids CO poisoning. This work presents a high-entropy alloyed single-atom strategy to realize efficient and durable methanol oxidation reaction catalysis with low costs. The methanol oxidation reaction is crucial for direct methanol fuel cells but is hindered by CO poisoning of Pt-based catalysts. Here, the authors report high-entropy alloyed single-atom Pt catalysts that resist CO poisoning, achieving a mass activity of 35.3 A mg-1 and maintaining high durability.