(172a) Statistically Guided Synthesis of Mov- Based Mixed Oxide Catalysts for Ethane Partial Oxidation

Efficient design of novel catalyst generally requires a clear understanding of the synthesis-performance relationship. More specifically, fundamental and empirical information is required to elucidate how different synthesis parameters affect both the final catalyst structure and its corresponding catalytic activity. Nano-structured catalysts are complex systems, in which multiple factors can influence catalytic activity. Such factors include particle size, surface structure, composition, or synthesis method; to name a few. Those factors have been found to be important in many industry-relevant reactions, such as ethane partial oxidation (EPO). For EPO, a promising reaction to upgrade ethane found in shale gas, catalysts are typically prepared through trial and error approaches without a thorough understanding of the highly correlated relationships between the synthesis parameters, structure factors, and the catalytic activity. If a systematic understanding is made available, it will be greatly beneficial to the design of more active/selective catalysts for EPO.

In this study, we utilize a statistical Design of Experiments (DOE) methodology to elucidate the relationship between different synthesis parameters and their effect on the catalytic activity and selectivity of EPO. Specifically, we will be exploring the effects of dopant addition to a base MoVNbO catalyst, which has shown promising activity for EPO and other hydrocarbon partial oxidations. To capture a multitude of the convoluted effects arising from changes to the synthesis parameters, in this case total dopant addition and relative ratio of redox to acid element; we will provide a detailed characterization of the crystalline structure, relative crystalline phase abundance, composition, and the catalytic activity/selectivity of EPO. By following these variables, we can construct a response surface to simultaneously correlate statistically significant changes in either crystalline structure, composition, or catalytic activity to the original synthesis parameters. Such results show that a ratio of 0.005 redox to acid functionality and a low overall dopant level is important to both maximize the formation ethylene/acetic acid and to maintain the structural integrity of the host metal oxide. By capturing multiple trends, we developed heuristics and guided synthesis parameters for the development of novel catalyst for ethane partial oxidation.