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Spectroscopic And Kinetic Study Of Copper-Exchanged Zeolites For The Selective Catalytic Reduction Of Nox With Ammonia, Shane Adam Bates Oct 2013

Spectroscopic And Kinetic Study Of Copper-Exchanged Zeolites For The Selective Catalytic Reduction Of Nox With Ammonia, Shane Adam Bates

Open Access Dissertations

The recent application of metal-exchanged, small-pore zeolites for use in the selective catalytic reduction (SCR) of NOx with ammonia NH3 for automotive deNOx applications has been a great stride in achieving emission standard goals. Copper-exchanged SSZ-13 (Cu-SSZ-13), the small-pore zeolite in this study, has been shown to be very hydrothermally stable and active under conditions presented in the exhaust of the lean-burn diesel engine. In this work, detailed studies were performed to identify many aspects of the active site(s) in Cu-SSZ-13 in order to learn about the standard SCR mechanism.

A series of seven Cu-SSZ-13 samples were …


Elucidation Of Chiral Recognition Mechanisms Of Solutes By Amylose Tris[(S)-Alpha-Methylbenzylcarbamate] Sorbent, Hung-Wei Tsui Oct 2013

Elucidation Of Chiral Recognition Mechanisms Of Solutes By Amylose Tris[(S)-Alpha-Methylbenzylcarbamate] Sorbent, Hung-Wei Tsui

Open Access Dissertations

Enantioselective separations of chiral molecules are important in various chemical fields, such as pharmaceuticals and agrochemicals industries. Polysaccharide-based sorbents have been widely used in chiral liquid chromatography. The recognition mechanisms which determine their enantioselectivities are not completely understood.

In this dissertation, the chiral recognition mechanisms of a widely used commercial sorbent, amylose tris[(S)-alpha-methylbenzylcarbamate], for benzoin (B) enantiomers were first studied. The HPLC data for benzoin with pure n-hexane as the mobile phase have been obtained. The behavior of sorbent-solute-hexane systems can be interpreted by considering only sorbent solute two-component interactions. Infrared (IR) spectra showed evidence of substantial hydrogen bonding (H-bonding) …