Platinum (Pt) represents the essential element for catalyzing the oxygen reduction reaction (ORR). However, the high cost of high Pt catalysts and inferior stability of low Pt catalysts commonly constructed are the primary factors limiting the scale application of the hydrogen fuel cell.
Based on the long-term accumulation of research on traditional catalysts, the meso catalysis group of Nanjing University led by Prof. Weiping Ding has developed a kind of low Pt electrocatalyst in a novel ternary heterostructure, Pt/CNx/Ni, in which the Pt and the underlying Ni nanoparticles are separated by nitrogen-doped carbon (CNx).
The well-engineered ternary heterostructure possesses the following merits:
(1) Matched band structures among the Pt, CNx and Ni, enable electrons to transfer from the inner Ni to the outer Pt, significantly promote the ORR activity of the low-Pt catalyst.
(2) Graphitized CNx layer prevents the underlying Ni nanoparticles from corrosion and maintains the designed structure enduringly.
(3) Strengthened interaction between the Pt and the electron-enriched CNx/Ni support mitigates the agglomeration or detachment of Pt nanoparticles significantly during the electrochemical process.
(4) Pt is protected from oxidation by the electron-enriched microenvironment.
Figure 1 exhibits the principle and performance of the catalyst. Pt/CNx/Ni shows ~780% enhanced specific mass activity or 490% enhanced specific surface activity compared with a commercial Pt/C catalyst. It well meets the standards proposed by the DOE of U.S. for fuel cell catalyst.
The meso catalysis group have continued the development of catalyst in the novel structure with independent intellectual property and push the application forward with the industry of fuel cell.
The work was described in iScience (https://doi.org/10.1016/j.isci.2018.12.029), subordinates to Cell press,titled as “Ternary Heterostructural Pt/CNx/Ni as a Supercatalyst for Oxygen Reduction” in the beginning of 2019. Thefirst author of the article is Teng Chen, a PhD candidate, and Prof. Weiping Ding and Associate Prof. Bin Zhao are corresponding authors. The work is supported by the Ministry of Science and Technology, the National Science Foundation of China and Nanjing Black-Tech Co. Ltd., China.
Figure1. The preparation, structure and catalytic performance of the ternary heterostructural Pt/CNx/Ni catalyst：a. synthetic process；b. electronic equilibration across the interfaces；c. morphology and size distribution of Pt nanoparticles；d. electrochemical performance and accelerated durability.