(Invited) Aqueous Thermal-Electrochemical Catalysis for Light Alkane Upgrading

The recent dramatic increase in supply of natural gas in the United States, largely enabled by rises in shale gas production, presents a unique opportunity to develop new catalytic processes that utilize abundant light alkanes for chemical manufacturing and transportation fuel synthesis. Alkenes as well as alcohols and other oxygenates are attractive target product molecules because they are either commodity chemicals or serve as precursors for production of commodity synthetic materials. This presentation will describe several approaches for designing new catalysts and reaction schemes for light alkane upgrading. These approaches include thermal catalytic, electrocatalytic, and hybrid thermal-electrocatalytic reactions in both batch and flow conditions. The presented work shows that oxidative functionalization of C-H bonds is possible using only air, water, and electricity as inputs when suitable catalysts and reaction conditions are utilized. Results demonstrate conversion of methane and ethane into a number of oxygenates and hydrocarbons at temperatures below 60 ºC in aqueous conditions, and quantify the associated catalytic performance. These efforts are supplemented by ex situ materials characterization and operando FTIR spectroscopy measurements, which provide new insights into the nature of these aqueous thermal and thermal-electrocatalytic reactions. The use of reactive oxidizing species generated from air and water for low temperature hydrocarbon catalysis has enormous potential to open new avenues of research. Additionally, the fundamental insights gained on the role of water in driving product selectivity in these reactions will be of interest to the broader catalysis community, which often encounter water in the gas phase as a side reactant.