Combined Catalytic Conversion of CH4 and CO2 to Value-added Products over the Oxide Supported Metal Catalysts from DFT-based Multiscale Study

Southern Illinois University At Carbondale, Carbondale IL

Investigators

Abstract

Abstract Title: Combined Catalytic Conversion of Methane and Carbon Dioxide to Value-added Products over the Oxide Supported Metal Catalysts from Multiscale Modeling Climate change resulting from anthropogenic green house gases, mainly carbon dioxide, is widely considered as a major threat faced by mankind. Recycling carbon dioxide in the production of useful chemicals or liquid fuel will complement carbon capture and sequestration and have a positive impact on global carbon dioxide levels, but such a process requires energy or hydrogen sources. Professor Qingfeng Ge of Southern Illinois University (SIU) Carbondale proposes to exploit methane as both hydrogen and energy source in a combined catalytic conversion process. Coupling methane partial oxidation reaction with the methane and carbon dioxide coupling reaction overcomes the thermodynamic limitation of the coupling reaction, thereby providing an atomically efficient route to utilize methane and carbon dioxide. Elucidating the catalytic mechanism of combined methane and carbon dioxide conversion will help improve the working catalysts and aid the rationale design of the new ones. Professor Ge will utilize the existing mechanisms at SIU Carbondale to recruit students from underrepresented groups to participate in the proposed cutting-edge research activities. The proposed research program contributes to the SIU Carbondale?s effort to build a student-centered research university with research strength in areas including energy and nanomaterials by enhancing the infrastructure for research and education. The proposed research program applies a first principles based multiscale approach to investigate metal-support interaction and its effect on catalytic conversion of CH4 and CO2 to value-added products, including acetic acid, alcohols, etc. A great challenge in developing a process that couples oxidation reaction with C-C coupling is to control the strength of oxidants?a too strong oxidant would over-oxidize methane and drive the reaction away from the coupling pathway. One focus of the proposed research is to test the reducible ZrO2, CeO2, and mixed oxides as oxygen carrier as well as support for selected transition metals, including Fe, Co, Ni and Rh. Thermodynamics analyses of the oxide surfaces together with the supported metal clusters of varying sizes will be performed to establish the effect of reaction environment on the stability of supporting oxides and supported metal clusters under reaction conditions. Elementary bond breaking and making steps, including C-H and C-O bond breaking and C-C bond formation, will be followed. The mechanistic understanding and energetic information will be integrated into a kinetic Monte Carlo (kMC) or mean-field approximation based micro-kinetic simulation to provide apparent kinetic parameters that may be compared directly with the experimental measurements. The proposed research will help to design catalysts that prevent complete combustion of methane. The proposed research program is built upon the experiences of the PI in surface science and catalysis and recent work on CO2 activation and hydrogenation. Collaborations with external experimental groups will provide a mechanism to test and validate the predictions and ideas from proposed research.