Di-nuclear Lewis acids (DNLA) made using a combined hydrothermal and post-synthetic approach
T2021-158 A novel method of creating catalytic material containing paired Lewis acids in combination with alkyl-metal precursors for improving the production of materials used in agricultural, chemical, and other commercial/industrial applications/processes.
The Need
More efficient techniques to create catalytic material are required to enable higher efficiencies and other performance improvements when used for manufacturing of specialty chemicals and other compounds. The conventional methods whereby Lewis acids play a role in catalysis has some key limitations - resulting in the need for, developing new/novel combinations such as well-defined paired Lewis acid sites. These new technologies could have a dramatic impact in terms of lower production costs and more efficient operations in manufacturing processes commonly used.
The Technology
OSU researchers have developed an enhanced catalytic material containing well-defined paired Lewis acid sites in a zeolite framework. They have leveraged precursors such as alkyl-Sn or alkyl-Ge to create open-defect Lewis acid sites. These defect sites act as targets for post-synthetic insertion of a second heteroatom. The Lewis acid pairs consisting of the first acid being alkyl-Sn or alkyl-Ge, and the second acid being one of the following: Sn, Zr, Hf, Ti, or Nb. When primary targets in the process, such as Ti-Ge, Sn-Sn, Zr-Sn, or Ti-Sn, are paired with different Lewis acid pairs the catalytic activity increases and thus adds value when used in application areas, such as epoxidation of olefins. In a similar manner, the inventors have demonstrated that Sn-Sn, and Sn-Zr pairs exhibit potential for activation of substrates for use in the aldol reaction process.
Commercial Applications
Changing over to using this technology where synthesizing catalytic materials with well-defined paired Lewis acid sites shows strong potential and ability to directly impact several areas in industrial processes. Some immediately impacted industrial processes would be the epoxidation of olefins and the aldol reaction, among many others.
Benefits/Advantages
The technology proposed here overcomes some of the main limitations in terms of instability and limited synthesizing capabilities in conventional approaches. It enables post-synthetic heteroatom insertion to generate distinct Lewis acid pairs in zeolites with the potential to expand the number of materials used to create efficient catalysts. The technology’s flexibility is further enhanced by providing a mechanism to incorporate a variety of heteroatom pairs into a zeolite framework.