I-Corps: The Commercialization Potential of Pyrazolate Metal-Organic Frameworks (MOFs)

University Of California-Berkeley, Berkeley CA

Investigators

Abstract

Metal-organic frameworks (MOF) are a class of materials built of inorganic clusters and rigid organic linkers to form open, three-dimensional frameworks that possess unique pore geometries and functionalities for novel material engineering. The use of MOFs provides safe alternatives for electrolytes, mitigate electrolyte degradation, and enable the use of high-energy electrode materials, such as sulfur, metal fluorides, and lithium that are traditionally limited by reaction with liquid electrolytes. They also enable the separation of alkane isomers by shape, which can be applied to gasoline upgrading, and enhance the margins of oil refineries by enabling them to either sell high octane gasoline for a premium or mix it into cheaper gasoline to reduce production costs. This I-Corps team has developed a class of conductive Metal-Organic Frameworks (MOFs), three-dimensional structures built of inorganic clusters and rigid organic linkers that display high ionic conductivities and electron mobility, as well as extraordinary selectivity for separation of alkane isomers. These properties make them suitable for applications in batteries and gasoline upgrading. Compared to traditional porous materials such as zeolites and activated carbons, MOFs have the wide diversity of pore structures and chemical properties that can be obtained by the judicious selection of metal ions and ligands. They can be further tailored by post-synthetic treatments to maximize conductivity or selectivity for separations. Upon chemical reduction, the electron mobility of the conductive MOFs becomes comparable to amorphous silicon and organic conductive polymers. By altering the ligand to access ligand-based redox couples, the capacity of MOFs could be drastically increased to values greater than materials used in lithium ion batteries. Thus, chemical modification can be used to enhance the conductivities of MOFs so that they can be applied to specific battery applications. At the same time, in contrast with the obtuse pore angles of zeolites, Fe2(BDP)3, a pyrazolate MOF has acutely angled pores. This enables the selection of molecules based on their shape, which provide varied adsorption enthalpies for linear, di and mono-branched alkane isomers for separation. As a result, separations currently carried out inefficiently, such as separating di-branched hexane isomers from mono-branched and linear isomers, could be performed with a substantially increased efficiency.