(582bn) Crystallization of One-Dimensional Zeolites By Nonclassical Pathways: Perspectives on Nucleation and Crystal Growth
AIChE Annual Meeting
2017
2017 Annual Meeting
Catalysis and Reaction Engineering Division
Poster Session: Catalysis and Reaction Engineering (CRE) Division
Wednesday, November 1, 2017 - 3:15pm to 4:45pm
Zeolites are microporous materials that are heavily utilized in commercial applications such as catalysis, separations, ion exchange, and adsorption, among others. Their utility is based largely on their unique characteristics that include excellent stability, well-defined networks of pores, and tunable physicochemical properties (i.e., shape, size, and composition). Despite significant effort to understand the formation of zeolites,1,2 their pathways of growth are not well understood owing to complex nonclassical mechanisms involving the assembly of precursors. For example, syntheses commonly lead to the formation of worm-like particles (WLPs), which are bulk amorphous precursors that serve as putative growth units during crystallization3. Evidence of crystallization by particle attachment (or CPA) is mounting for a range of materials that include biominerals4, metal oxides5, and zeolites6. Here, we will discuss the pathways of formation for two one-dimensional zeolites (LTL and TON types). We will discuss the results of standard synthesis protocols that incorporate crystal seeds and/or zeolite growth modifiers (ZGMs), which are molecules that alter the anisotropic growth rate(s) of zeolite crystallization. The results presented here focus on fundamental aspects of zeolite nucleation and growth, as well as describing how we can capitalize on this knowledge to rationally design materials with superior performance than those derived from conventional synthesis methods.
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(2) Choi, M.; Na, K.; Kim, J.; Sakamoto, Y.; Terasaki, O., et al.; Nature. 461 (2009)246-249
(3) Kumar, M.; Li, R.; Rimer, J. D.; Chem. Mater. 28 (2016)1714-1727
(4) Politi, Y.; Arad, T.; Klein, E.; Weiner, S.; Addadi, L.; Science. 306 (2004)1161-1164
(5) Penn, R. L.; Banfield, J. F.; Science. 281 (1998)969-971
(6) Lupulescu, A. I.; Rimer, J. D.; Science. 344 (2014) 729-732