Search Results - wei+fan

Zeolites have found wide application in catalysis and separation processes due to their tunable pore structure and active sites, and they show remarkable stability in commercial use. Recently, ultra-thin two-dimensional (2D) zeolite nanosheets have been synthesized from zeolite precursors. These ultra-thin nanosheets show promise for high throughput separations and catalytic reactions involving bulky molecules. A commercially feasible synthesis method, however, has yet to be developed. State-of-the-art methods require high energy input and multiple processing steps, and give low yield and small nanosheet size.

 

Professors Winter and Fan have developed a simpler, lower energy method to synthesize ultra-thin 2D zeolite nanosheets from precursor zeolite materials, such as MCM-22 and ml-MFI. In the method, zeolite precusors can be subjected to either a short sonication or chaotic flow treatment in the presence of commercially available telechelic polymers, resulting in exfoliated zeolite nanosheets. While demonstrated in batch, this process can potentially be scaled and made continuous.

Heteroatom containing zeolite catalysts have shown excellent catalytic activity and thermal stability in petrochemical processes as well as for converting biomass into biofuels and high-value chemicals. However, their synthesis is difficult, requiring harsh chemicals and long synthesis times.

 

This patented technology is several rapid, high-yield synthesis methods for heteroatom containing zeolites, such as Sn-Beta. The method begins with adding zeolite seeds to a solution comprising a heteroatom source and a structure-directing agent. By directly adding the seeds to the solution without calcination or drying, the seeds do not agglomerate and as a result, crystallization time is shortened. To complete catalyst synthesis from the resulting gel, it is then heated to form a solid, filtered, washed, dried, and finally calcined.

 

Specific methods disclosed in this patent include one as short as 2 days and the first fluorine-free synthesis route. The catalysts were demonstrated to be active for both sugar isomerization and dehydration reactions, necessary in fuel and chemical synthesis.