Clean, efficient and sustainable energy storage and conversion devices are bound to occupy an important place in the future energy architecture. Among them, fuel cells and metal-air batteries have attracted much attention in the field of mobile power sources due to their simple operation, high efficiency and environmental protection. However, there are still many problems in the commercial application of this type of battery. The most prominent one is that the kinetic reaction rate of oxygen reduction reaction (ORR) at the cathode of the battery is slow, and the large polarization overpotential causes the output power and efficiency of the battery to be greatly reduced. The search for efficient, stable and inexpensive cathode catalysts is the key to the commercialization of batteries. Professor Wang Deli's team is committed to the design and development of low-platinum and non-platinum catalysts and the study of structure-activity relationship. It is expected that the structural parameters of catalysts will be analyzed through theoretical design and advanced physical characterization methods, and the structure-activity relationship of building materials will be revealed through experimental research. Provide guidance and basis for the design and application of related catalysts. In this study, ordered PdZn(O-PdZn) nanocatalysts with surface Pd-rich (5-6 atomic layer thickness) were prepared by a simple impregnation reduction method and subsequent high temperature treatment. The ORR test results in an alkaline environment show that the catalyst exhibits a 3-fold increase in mass activity compared to Pd/C and Pt/C. In order to better improve its cycling stability, the corrosion-resistant Au atoms were modified in the catalyst by spontaneous replacement strategy. The results showed that the modified catalyst (Au-O-PdZn) only decayed by 6mV after 30,000 cycles at half-wave potential. Electrochemical tests by assembling the as-prepared catalyst into zinc-air batteries and lithium-oxygen batteries demonstrate that the catalyst has certain practical application potential.
Since joining in early 2013, Professor Wang Deli's research group has made a series of research progress in the design and structure-activity relationship of low platinum catalysts. In 2018, the research group published an invited review on the design and structure-activity relationship of low-platinum ORR catalysts in ACSCatalysis (ACS Catal., 2018, 8(4), 3237-3256, DOI: 10.1021/acscatal.7b04420). On April 5, 2019, the research group continued to publish a research paper entitled "One-Nanometer-ThickPt3NiBimetallicAlloyNanowiresAdvancedOxygenReductionReaction: IntegratingMultipleAdvantagesintoOneCatalyst" in the journal ACSCatalysis. The first author of the paper is Gong Mingxing, a 2016-level PhD student, and the co-first author is a 2015-level undergraduate student. Deng Zhiping. In the study, the authors synthesized ultrafine (1nm) Pt3Ni bimetallic nanowires by a simple hydrothermal synthesis method, introducing Ni source and reasonably adjusting the solvent polarity. The simulated structure found that the utilization rate of Pt atoms reached 50%. At the same time, it was found that the ORR catalytic performance of the catalyst was effectively improved due to the ultra-high surface Pt atom utilization, ultra-fine 1D nanowire structure, and the electronic structure effect and stress effect control brought by alloying. Other related research results were published in NanoEnergy, Chem.Mater. and other journals.