Recently, Professor Meng Gu from the Department of Materials Science and Engineering (MSE) at the Southern University of Science and Technology (SUSTech) and Professor Joseph S. Francisco from the Department of Chemistry at the University of Pennsylvania (UPenn) collaborated to report an iridium single-atom on Ni₂P catalyst (Ir_SA-Ni₂P) with a record low overpotential of 149 mV at a current density of 10 mA·cm⁻² in 1.0 M KOH. Their study, entitled “Single Iridium Atom Doped Ni₂P Catalyst for Optimal Oxygen Evolution,” was published in the high-impact journal Journal of the American Chemical Society.

In this study, Prof. Gu and Prof. Hu Xu from SUSTech, and Prof. Francisco from UPenn reported a single iridium atom on Ni₂P catalyst (Ir_SA-Ni₂P) with a record low overpotential of 149 mV at a current density of 10 mA·cm−2 in 1.0 M KOH. The Ir_SA-Ni₂P catalyst delivers a current density up to ~28-fold higher than widely used IrO2 at 1.53 V. Both the experimental results and computational simulations indicated that Ir single atoms preferentially occupy Ni sites on the top surface.

The reconstructed Ir-O-P/Ni-O-P bonding environment plays a vital role in optimal adsorption and desorption of the OER intermediate species, which leads to marked enhancement of the OER activity. Additionally, the dynamic “top-down” evolution of the specific structure of the Ni@Ir particles is responsible for the robust single-atom structure, and thus, the performance stability. This Ir_SA-Ni₂P catalyst offers novel prospects for simplifying decoration strategies and further enhancing OER performance.

Figure 1. Atomic structure recognition of Ir single atom

They extended the synthetic route to achieve other single-atom decorated Ni₂P, including Ru, Rh, and Au. The excellent OER Ir_SA-Ni₂P catalyst enabled in-depth insights into the catalytic pathway for OER and the novel formation mechanism of the single atom.

Dr. Qi Wang, a researcher from the College of Engineering at SUSTech, Dr. Chao Cai, a researcher at SUSTech, Zhe Zhang, a Ph.D. candidate from SUSTech, and Prof. Hu Xu are the co-first authors of this paper. Professor Meng Gu from MSE at SUSTech and Professor Joseph S. Francisco from UPenn are the corresponding authors.

This work was supported by the National Natural Science Foundation of China (NSFC), Entrepreneurial Research Team Program, Shenzhen Peacock Plan, and the Shenzhen Clean Energy Research Institute.

Paper link: https://pubs.acs.org/doi/10.1021/jacs.1c04682