Analysis of Molybdenum and Iron Catalyzed Non-Oxidative Methane Coupling

Methane conversion reactions are of high value to the chemical and energy industries, as a wide range of products such as acetylene, ethane, ethylene, or methanol can be produced from the abundant feedstock supplied by natural gas. Non-oxidative methane coupling in particular is a clean way to produce these chemicals with minimal coking, greater production of useful byproducts such as hydrogen, and no production of undesirable byproducts such as carbon monoxide. Due to the high stability of methane, however, this class of reactions is considered one of the holy grails of catalysis research. If the low activity and selectivity of this reaction can be overcome, it could lead to significant advancements in the production of high value and widely used chemicals such as ethylene. In this investigation, molybdenum and iron supported monometallic and bimetallic catalysts were synthesized via incipient wetness impregnation and tested in the non-oxidative methane coupling reaction. Various characterization techniques including H₂ temperature programmed reduction, CO chemisorption, N₂ physisorption, and X-ray diffraction were employed on the different catalysts. Reaction performance was measured in a fixed bed flow reactor with a feed of methane and nitrogen at 700°C. Pre carburization was conducted by flowing pure methane for a brief period of time once the catalyst reached the target temperature and then beginning the designated reaction feed gas mixture. The outlet gas concentration was analyzed by gas chromatography. Through this method we have determined appropriate reaction conditions, i.e. temperature, gas flow, catalyst mass, and time, for investigation of these catalysts. Ongoing work is investigating the performance and properties of these catalysts to inform future catalyst modifications. The improvement of catalysts for non-oxidative methane coupling could eventually lead to a higher selectivity of desirable products for industrial methane conversion processes, increasing the economic gain and decreasing the waste generated by this reaction.