& Heterogeneous Catalysis | Hot Paper | Facile Synthesis, Characterization, and Catalytic Behavior of a Large-Pore Zeolite with the IWV Framework Joel E. Schmidt, [a] Cong-Yan Chen, [b] Stephen K. Brand, [a] Stacey I. Zones, [b] and Mark E. Davis* [a] Abstract: Large-pore microporous materials are of great interest to process bulky hydrocarbon and biomass-derived molecules. ITQ-27 (IWV) has a two-dimensional pore system bounded by 12-membered rings (MRs) that lead to internal cross-sections containing 14 MRs. Investigations into the cat- alytic behavior of aluminosilicate (zeolite) materials with this framework structure have been limited until now due to barriers in synthesis. The facile synthesis of aluminosilicate IWV in both hydroxide and fluoride media is reported herein using simple, diquaternary organic structure-directing agents (OSDAs) that are based on tetramethylimidazole. In hydroxide media, a zeolite product with Si/Al = 14.8–23.2 is obtained, while in fluoride media an aluminosilicate product with Si/Al up to 82 is synthesized. The material produced in hydroxide media is tested for the hydroisomerization of n- hexane, and results from this test reaction suggest that the effective pore size of zeolites with the IWV framework struc- ture is similar to but slightly larger than that of ZSM-12 (MTW), in fairly good agreement with crystallographic data. Introduction Microporous crystalline materials are solids with pores of less than 2 nm. They are formed from three dimensional networks of oxide tetrahedra, and offer shape- and size-selective envi- ronments for catalysis, absorption and ion exchange in materi- als that often exhibit robust hydrothermal stability. There are currently over 200 distinct microporous material frameworks that differ in pore shape, size and dimensionality, presence or absence of internal cages, and composition. [1] One of the most important distinctions between frameworks is the size of the pores, which are defined by the number of tetrahedral (T-atoms) that border them. Pores defined by eight T-atoms (8 MR) are considered small-pore materials, 10 MR are medium pore materials, and 12 MR are termed large-pore materials. Ma- terials with large pores are of great interest to process bulky hydrocarbon and biomass-derived molecules. [2] The commer- cial market for zeolites is dominated by five frameworks, *BEA, FAU, FER, MFI, and MOR, and of these, three are large-pore ma- terials (*BEA, FAU, and MOR), and a single large-pore material, FAU, dominates 95% of the synthetic zeolite market, as it is used for fluidized catalytic cracking. [3–5] Although such market dominance may seem to imply research stagnation in the field, the fact that only a single framework and composition (as well as further modification by post-synthetic treatments) often delivers adequate performance in a given application means that the development of new microporous material frame- works and compositions is an area of considerable research efforts. [4, 6–10] Some of the strategies employed in recent years in the quest for new materials include: new organic structure-direct- ing agents (OSDAs), the use of fluoride as a mineralizing agent coupled with low-water syntheses and germanium as a frame- work element. [11] Among these strategies, the use of new OSDAs has received a great amount of attention. Although computational guidance has been used in some limited cases to predict OSDAs for desired phases a priori, the majority of discoveries are made through serendipity. [12–16] OSDAs are gen- erally quaternary alkylammonium molecules, though OSDAs based on phosphonium [7, 11, 17–20] and sulfonium [21] chemistry are also known. Phosphonium OSDAs are especially advantageous as they do not undergo Hoffman degradation, making their use under severe crystallization conditions possible. However, a potential drawback of phosphonium OSDAs is that phospho- rous remains in the materials after calcination. One of the first, new microporous materials discovered using phosphonium OSDAs is ITQ-27 (IWV), that consists of a 2D pore system limited by 12 MRs, but containing internal 14 MRs. [17, 22] ITQ-27 was discovered by using dimethyldiphenylphosphonium as the OSDA and a synthesis composition of SiO 2 :0.014 Al 2 O 3 :0.50 Me 2 Ph 2 POH :0.50 HF :(3–4.2) H 2 O. The prepa- ration was reported to take 59 days to form the product (the addition of seeds only shortens this by one week). While a broad compositional range was claimed for ITQ-27 in the patent literature [22] , the product was only reported as having a Si/Al = 29.5. [a] Dr. J. E. Schmidt, S. K. Brand, Prof. M. E. Davis Chemical Engineering, California Institute of Technology Pasadena, CA 91125 (USA) E-mail : mdavis@cheme.caltech.edu [b] Dr. C.-Y. Chen, Dr. S. I. Zones Chevron Energy Technology Company, Richmond, CA 94802 (USA) Supporting information for this article is available on the WWW under http ://dx.doi.org/10.1002/chem.201504717. Chem. Eur. J. 2016, 22, 4022 – 4029 # 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim 4022 Full Paper DOI: 10.1002/chem.201504717