Abstract
Proton exchange membrane fuel cell (PEMFC) has attracted enormous attention as a viable, clean, and sustainable power generation technology alternative to widely employed fossil fuel-based technologies. Hydrogen oxidation reaction at the anode of a PEMFC is facile. In contrast, oxygen reduction reaction (ORR) at the cathode of PEMFC is sluggish due to a strong O-O bond in O2 molecule and requires an efficient electrocatalyst for the effective reduction of O2 to H2O. Currently, platinum group metals are found to be the best ORR electrocatalysts. The price of rare and expensive Pt-based electrocatalysts contributes significantly to the total cost of a fuel cell and hinders its mass application. Therefore, it is of great interests to investigate how to reduce and even eliminate Pt contents in the ORR electrocatalysts. In this seminar, I will present a computational study elaborating the ORR reaction mechanisms on Pt alloy catalysts and carbon-supported nitrogen-derived non-precious transition metal (TM-N/C, TM=Fe or Co) catalysts. Specifically, I will first discuss how the sub-surface transition metal could cause a shift in the d-electron band of the Pt alloy catalysts (such as, PtNi, PtCo and PtFe) and thus favorably modify the energetics of the ORR occurring on these Pt alloy catalysts. Moreover, I will examine the possible pathways of the ORR on the TM-N4 clusters of the TM-N/C catalysts using the first-principles density functional theory calculation method. In particular, I will show that the ORR activity of the TM-N4 clusters could be tuned by tailoring the energy levels of the non-bonding d-orbitals of the central TM atoms. Consequently, I demonstrate in this seminar that physics-based computational techniques are essential for accelerating, achieving, and amplifying research discoveries in the current forefronts of developing electrocatalysts for PEMFCs.           

About the Speaker.   王国峰：Associate Professor，Department of Mechanical Engineering and Materials Science, University of Pittsburgh. 1995年获得清华大学学士学位。1997年获得清华大学硕士学位。2002年获得California Institute of Technology 材料学博士学位。2002-2005年曾在Lawrence Berkeley National Laboratory 工作。现任教于University of Pittsburgh. 研究方向涵盖计算材料学的多个前沿领域，包括Quantum Monte Carlo method、novel electrocatalysts for fuel cells, high-entropy alloys, and additive manufacturing.。在Science, Nature Materials, Physical Review Letters，Advanced Functional Materials, Nano Letters 等国际知名期刊上发表了57篇科技论文，引用超过3800次。