Jun 5, 2019
Professor Xiangfeng Duan
Team reported a single-atom decoration approach to greatly boost the platinum nanocatalysts for efficient electrical to chemical energy conversion or vice versa.
 
The study titled “Single-atom tailoring of platinum nanocatalysts for high-performance multifunctional electrocatalysis” was published online in the prestigious journal Nature Catalysis on May 20, 2019.
 
The research team was led by Xiangfeng Duan, UCLA professor at the Department of Chemistry and Biochemistry; Yu Huang, UCLA professor of Materials Science and Engineering at the UCLA Samueli School of Engineering; and Philippe Sautet, UCLA professor of the Chemical and Biomolecular Engineering at the UCLA Samueli School of Engineering. 
 
The lead authors (contributing equally) of the study are alumnus Dr. Mufan Li (Ph.D. ’17 chemistry, Duan Group, and a postdoc fellow in Huang group), Dr. Kaining Duanmu, a postdoctoral researcher in Sautet group, and graduate student Chengzhang Wan in Duan group. 
 
To learn more about the Duan group's research, visit their website.
 
Schematic diagram of single atomic decorated platinum nanowire catalyzing multiple electrocatalytic reactions.
 
The international team led by researchers at UCLA has demonstrated how to precisely decorate the platinum nanowires with atomically isolated nickel hydroxide species. Such atomic scale decorations could effectively modify the local electronic structure of the catalytic sites to greatly improve the catalytic performance of Pt nanowires in multiple electrocatalytic reactions. It will greatly increase the metal utilization efficiency previous metal catalysts and reduce the cost for relevant technologies. This is particularly important for those catalysts using precious metals.
 
Electro-catalysis plays a crucial role in renewable clean energy conversion, storage and utilization. With excellent intrinsic electrocatalytic activity and electrochemical stability, platinum (Pt) represents the most iconic element for various electro-catalysis systems, such as hydrogen evolution reactions (HER), oxygen reduction reactions (ORR) and alcohol oxidation reactions (AOR) that are important for solar fuel generation and the development of environmentally friendly fuel-cell vehicles. However, the high cost of Pt has seriously limited the practical application of the Pt-based electrocatalysts and the widespread adoption of the relevant technologies.
 
By using a highly controllable electrochemical de-alloying process, the research team demonstrate that the platinum-nickel alloy nanowires can be transformed into the ultrafine platinum nanowires with single atom nickel species decorated on surface. These single-atom nickel species modify the electronic structure of the nearby Pt atoms, tailoring the hydrogen bind energy to optimal level and enable the record high activity for hydrogen evolution reactions. Additional experimental investigations and density functional theory (DFT) simulations further revealed that such single atom modification approach can also weaken the carbon monoxide binding strength on the adjacent Pt atoms, leading to greatly enhanced catalytic activity for methanol oxidation reaction (MOR) and ethanol oxidation reaction (EOR) while minimizing the catalyst poisoning.
 
This single atom decoration approach offers an effective strategy for tailoring the local electronic structure and the catalytic properties of Pt nanocatalysts, with minimum blockage of the active sites. It could open a new pathway to the design of highly efficient precious metal-based catalysts vastly outperforming the state-of-art.
 
The research was supported by the National Science Foundation, the office of Naval Research. The calculations were performed on the Hoffman2 cluster at UCLA Institute for Digital Research and Education (IDRE).
 
Article by Professor Xiangfeng Duan, Dr. Mufan Li, and Chengzhang Wan.