Topic：Operando Monitor the Dynamic Structure Change of Metal Alloyed Nanoparticles Under Oxygen Evolution Reaction in Acidic Condition
Speaker：Dongshuang Wu （School of Materials Science Engineering, Nanyang Technological University, Singapore）
Time：14:30 (Thur.)，Dec.14, 2023
Venue：Room 403，shichangxu Building, IMR CAS
Metal nanoparticles goes through various structure changes under oxygen evolution reaction (OER) conditions. The successes in solid polymer exchange membrane technology accelerate water electrolysis in acid instead of conventional alkaline media1. However, the critical bottleneck lies in oxygen evolution reaction, particularly in acidic media, because most metals dissolve in the working potential region according to Pourbaix diagrams. Quite recently, there are quite a few reports that metal alloyed nanoparticles (NPs) have superior OER activity and durability to their bulk stable oxide counterpart.2,3 However, the dynamically changed crystal and electronic structure of the metal NPs during OER hinder the further understanding of the OER mechanism. Here, using RuIr alloyed nanocatalysts as an example, we monitored their dynamic changes during OER by developing various operando characterization including X-ray based spectroscopies and X-ray diffraction. By combining the operando characterization with the high-resolution electron microscopy and electrochemical method, the OER mechanism on the metal-based catalysts will be revealed. In the end, I will briefly introduce the recently developed ambient pressure hard X-ray photoelectron spectroscopy (HAXPES) 4 in the electrochemistry field.
[Reference]
1.Seitz, Linsey C., et al. "A highly active and stable IrO x/SrIrO3 catalyst for the oxygen evolution reaction." Science 353.6303 (2016): 1011-1014.
2.Wu, Dongshuang, et al. "Efficient overall water splitting in acid with anisotropic metal nanosheets." Nature communications 12.1 (2021): 1145.
3.Reier, Tobias, Mehtap Oezaslan, and Peter Strasser. "Electrocatalytic oxygen evolution reaction (OER) on Ru, Ir, and Pt catalysts: a comparative study of nanoparticles and bulk materials." ACS Catalysis 2.8 (2012): 1765-1772.
4.Wu, Dongshuang, et al. " Noble-metal high-entropy-alloy nanoparticles: atomic-level insight into the electronic structure." J. Am. Chem. Soc., 144 (2022): 3365-3369
Biography
Dr. WU Dongshuang is Nanyang Assistant Professor in the School of Materials Science and Engineering (MSE) at Nanyang Technological University (NTU) in Singapore. Her work spans in synthesizing novel metal-based nanomaterials tailored for catalytic applications, encompassing both electrocatalysis and thermal catalysis. A close collaboration with prominent scientific facilities on a large scale characterizes her efforts, notably synchrotron facilities in Japan, Germany, China, Korea and the USA. Her endeavors include conducting operando measurements alongside data analyses utilizing X-ray based spectroscopies. Her research is deeply dedicated to experimentally elucidating the influence of electronic structure and crystal arrangement on the physical and chemical properties.
