Researchers Develop Large-Pore Zeolite with Potential Benefits to Catalysis

23 October 2006

The main channels of ITQ-33 are 12.2Å in diameter. The secondary channels are not visible in this view.

Researchers at the Spanish National Research Council and Polytechnic University of Valencia (Spain) have created a new zeolite material that features unusually large pores and interconnecting channels. Zeolites are used in numerous applications in catalysis, gas storage and electronics.

The architecture of the new zeolite, named ITQ-33, features a very large-diameter ring structure intersected by a second, medium-diameter structure. The structure of the new zeolite, along with its thermal stability, may enable more efficient catalytic operations on large molecule hydrocarbons in the petroleum and chemical industries.

Two different views of the zeolite. Click to enlarge.

The new silicogermanate material features straight channels with circular openings of 18 rings measuring 12.2 Å in diameter that are interconnected by a bi-directional system of 10-ring channels (5.6 Å diameter) that run perpendicular to the larger channels.

The system of interconnecting channels qualifies ITQ-33 as the zeolite with the largest percentage of internal empty space, and provides room for larger molecules as well as for bypassing blocked passages. In a description of their work published in Nature, the developers report that the zeolite is very active catalytically, in some cases outperforming current commercial catalysts.

In a commentary on the work also published in Nature, Raul F. Lobo, professor of chemical engineering at the University of Delaware, notes that while other research groups have prepared large-pore zeolites, ITQ-33 offers superior properties, and has “great potential as an industrial catalyst.”

Resources:

• “High-throughput synthesis and catalytic properties of a molecular sieve with 18- and 10-member rings”; Avelino Corma, María J. Díaz-Cabañas, José Luis Jordá, Cristina Martínez and Manuel Moliner; Nature 443, 842-845(19 October 2006) | doi:10.1038/nature05238