CAS: Ambient Electrochemical Activation of Light Alkanes with Early Transition Metal-Oxo Species

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The abundant, yet widely geographically distributed, natural gas and oil resources in North America have dramatically changed the United States energy portfolio. Conversion of natural gas to useful products relies on high temperature and high pressure processes at centralized locations. Transportation of natural gas from remote sources to these central locations is often not economical. As a result, natural gas is often discarded by flaring at the well, while the oil is recovered. Natural gas, which is mostly methane, and its flaring product, carbon dioxide, are both potent greenhouse gases. Development of catalytic processes that convert natural gas into economically-transportable liquids at these well sites is very desirable. In this project, Professor Chong Liu of the University of California, Los Angeles is developing a new approach using electricity to convert light alkanes, including methane, into liquid products. Dr. Liu is studying new electrochemical catalysts and investigating the fundamental mechanisms of these reactions. Dr. Liu is actively engaged in outreach and education activities to promote engagement of students in science, technology, engineering and mathematics (STEM) disciplines. These activities include the introduction of chemistry topics to local gardeners and farmers in the Los Angeles area as well as undergraduate advising for general chemistry courses assisted by machine learning.With the funding from the Chemical Catalysis Program of the Division of Chemistry, Dr. Liu of the University of California, Los Angeles is developing a mechanistic understanding of how early transition metal-oxo species break the carbon-hydrogen bond in methane during the catalysis. A variety of electrochemical techniques in conjunction with in situ characterizations (including X-ray absorption spectroscopy) are employed to identify important transient intermediate species and determine reaction kinetics with the assistance of first-principle calculations. Also under investigation is the exploration of other molecular and materials catalysts for electrochemical conversion of light alkanes under ambient conditions. Dr. Liu takes soil samples and analyzes their composition for local gardeners and farmers, assisting the local community to develop sustainable agriculture and gardening practices. Dr. Liu is also developing a machine-learning-based platform to develop teaching strategies in general chemistry courses, to advise students on course enrollment, and, in the long run, to establish an online advising program for career development.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.