Title: Magnetization Enhanced Water Oxidation on Magnetic Catalysts
Speaker: Prof. Zhichuan Xu (Nanyang Technological University, Singapore)
Time: May 11, 10:00-11:00
Venue: Conference Room 105, Shaw Engineering Hall, Guangzhou Wushan Campus
[Abstract]
Applying an external magnetic field to electrochemical reactions is recently an interesting topic among the electrocatalysis community. Earlier studies have shown that the water oxidation reaction (also called oxygen evolution reaction, OER) can be promoted by an external magnetic field through the promoted bubble removal on the electrode surface. However, that is for the case under the high overpotential and high current applied. In 2019, it has been reported that the promotion of OER in alkaline by applying the field is related to the magnetism of the electrode materials. On the other hand, theoretically, the OER needs to consider the triplet O2 formation, which involves the spin-polarized electron transfer. The spin-polarized electron transfer can be achieved by ferro(i) magnetic catalysts, however, which may not be easily proved experimentally. That is because in principle, an external magnetic field is not necessary for spin-polarized electron transfer on ferro(i)magnetic materials. It is also unclear about the reaction pathways with a consideration of spin-polarized electron transfer. The pH dependent enhancement has further generated confusion about the relation between magnetic field enhanced OER and the theoretical expectation. In addition, some magnetic catalysts do not exhibit any improvement under the magnetic field. All these phenomena have created a scientific puzzle, appealing to the community. In this talk, I will briefly discuss the progress of this field and several important experimental findings for solving the puzzle. The critical roles of magnetization, pinning effect, and pH dependent increment will be discussed in detail.
Announced by School of Chemistry and Chemical Engineering
