简介: |
Abstract
The long term goals of my research are to understand industrially relevant catalysts to improve their activity and selectivity, and to develop inexpensive and efficient catalysts for low-carbon fuel production. In this seminar, I will show how I have used computational chemistry to reach this objective in the areas of heterogeneous catalysis, molecular catalysis, and electrocatalysis.
My investigation of the mechanism of n-butane selective oxidation to maleic anhydride on a vanadium phosphorus oxide surface (VPO) is representative of my work in heterogeneous catalysis. Surprisingly, I found that O=P on the VVOPO4 surface is the active center for initiating the VPO chemistry through the extraction of H from alkane C-H bonds. This work not only sheds light on VPO chemistry but also demonstrates the importance of main group oxo ligands in heterogeneous catalytic reactions. I then proposed a series of organometallic molecules that activate C-H bonds through this unique mechanism.
My research in the area of molecular catalysis has focused on methane-to-methanol transformation, especially the formation of C-O bonds. In this context I discovered a new mechanism for generating C-O bonds from metal-hydrocarbyl. This mechanism proceeds via an intermolecular hydrocarbyl migration to the oxo of a separate oxidant leading to one-electron reduction for both metals on the reactant and oxidant. It represents one of the few ways for oxy-functionalizing metal-carbon bonds.
In the area of electrocatalysis, I have studied the electrochemical oxygen evolution reaction (OER) of water and the oxygen reduction reaction (ORR) on metal-porphyrin-like centers incorporated into carbon nanostructures. I discovered that the overpotential for OER and ORR can be reduced by more than 0.30 V by the choice of the axial ligand. Based on this discovery, I proposed two novel electrocatalysts for OER and ORR.
Biography: Mu-Jeng Cheng received his M.Sc. from National Tsing-Hua University, Hsinchu, Taiwan before moving to the California Institute of Technology, United States, where he obtained his Ph.D. under the supervision of Prof. William A. Goddard in 2012. After working in Prof. Goddard group for an additional year as a postdoc and member of the research staff, he joined the Joint Center for Artificial Photosynthesis, Lawrence Berkeley National Laboratory as a postdoc under the joint-supervision of Prof. Alexis T. Bell and Prof. Martin Head-Gordon. Energy and industry related problems in heterogeneous catalysis, molecular catalysis, and electrochemical catalysis are the focus of his research, in which he uses computational approaches based on both quantum mechanics (density functional theory) and classics mechanics (reactive force field, ReaxFF) to study and design novel catalysts. |
