UNS: Selective Catalytic Conversion of Syngas-Derived Dimethyl Oxalate to Ethylene Glycol: Mechanistic Insights from In-Situ Surface Vibrational Spectroscopy

University Of South Carolina At Columbia, Columbia SC

Investigators

Abstract

1510157 Williams, Christopher T The proposed work will examine the reactions involved in producing ethylene glycol (EG) - an important industrial chemical - from synthesis gas via catalytic dehydrogenation reactions of dialkyl oxalate intermediates. This opens the door to EG production from non-conventional sources such as coal, natural gas, and biomass instead of the conventional process based on ethylene oxide produced from petroleum resources. Although the technology has been used for several decades, new catalyst formulations, as well as more advanced characterization techniques suitable for analysis under reaction conditions, present an opportunity to obtain a more detailed understanding of the catalytic mechanism, and thereby further develop the catalyst technology. The techniques developed as part of the project will be broadly applicable to a range of catalytic processes - especially those carried out in liquids. The principal investigator will also integrate international research opportunities and research opportunities targeting underrepresented groups into the project. The project will examine the surface chemistry involved in the hydrogenation of various dialkyl oxalate species on Cu, Ag, Au-Cu, and Au-Ag catalysts - both supported and unsupported - and both in the gas and liquid phases. Critical to the project will be the implementation of a new attentuated total reflection infrared spectrophotometer (ATR-IR) as the primary tool and through design of a new high-pressure and high-temperature ATR-IR cell. Application of the new ATR-IR cell, together with reaction kinetics obtained under the same conditions, should shed new insight on the catalytic reaction mechanism and factors affecting catalyst stability and poisoning. A unique feature of the study is that experiments will be conducted in both gas phase and liquid phase environments under conditions close to those utilized in industrial practice. The fundamental nature of the project, involving relatively complex organic chemicals and multiple reaction pathways, as well as reaction in both aqueous and gas phase environments, makes it an important test-bed for the improved experimental capabilities offered by the high pressure/temperature ATR-IR cell. Information derived from the study should offer insight into a broad range of catalytic processes ranging from electrocatalysis to photocatalysis and to catalytic conversion of biomass intermediate products. Catalysis in liquid phase environments will be particularly amenable to study by the tools and techniques demonstrated in this project. The PI will also integrate several novel educational opportunities into the proposed research project, including an international research experience for his graduate students, and research opportunities for underrepresented groups at both the graduate and undergraduate levels.