Claire A. Murray

Elucidation of Adsorbate Structures and Interactions on Brønsted Acid Sites in H-ZSM-5 by Synchrotron X-ray Powder Diffraction.

Microporous H-ZSM-5 containing one Brønsted acid site per asymmetric unit is deliberately chosen to host pyridine, methanol, and ammonia as guest molecules. By using new-generation inu2005situ synchrotron X-ray powder diffraction combined with Rietveld refinement, the slight but significant alteration in scattering parameters of framework atoms modified by the guest molecules enables the user to elucidate their adsorption geometries and interactions with the Brønsted acid sites in H-ZSM-5 in terms of atomic distances and angles within experimental errors. The conclusion, although demonstrated in the H-ZSM-5, is expected to be transferable to other zeolites. This approach provides a stepping stone towards the rational engineering of molecular interaction(s) with acid sites in zeolitic catalysis.

Decarboxylation of Lactones over Zn/ZSM‐5: Elucidation of the Structure of the Active Site and Molecular Interactions

Herein, we report the catalytic decarboxylation of γ-valerolactone (GVL) over Zn/ZSM-5 to butene, followed by aromatization at high yield with co-feeding of water. An evaluation of the catalytic performance after prolonged periods of time showed that a water molecule is essential to maintain the decarboxylation and aromatization activities and avoid rapid catalyst deactivation. Synchrotron X-ray powder diffraction and Rietveld refinement were then used to elucidate the structures of adsorbed GVL and immobilized Zn species in combination with EXAFS and NMR spectroscopy. A new route for the cooperative hydrolysis of GVL by framework Zn-OH and Brønsted acidic sites to butene and then to aromatic compounds has thus been demonstrated. The structures and fundamental pathways for the nucleophilic attack of terminal Zn-OH sites are comparable to those of Zn-containing enzymes in biological systems.

Impact of partial interpenetration in a hybrid ultramicroporous material on C2H2/C2H4 separation performance

Phases of a 2-fold pcu hybrid ultramicroporous material (HUM), SIFSIX-14-Cu-i, exhibiting 99%, 93%, 89%, and 70% partial interpenetration have been obtained. 1u2009:u200999 C2H2/C2H4 gas separation studies reveal that as the proportion of interpenetrated component decreases, so does the separation performance.

Fast microwave treatments of single source alkoxides for nanostructured Li-ion battery electrodes

Microwave or ultrasonic treatment of metal alkoxides presents a fast, low cost route to both anode and cathode nanomaterials for Li-ion battery applications. Here, we demonstrate the formation of LiMPO4 (M = Fe, Mn) and Mn3O4 nanostructures via this simple route which exhibit excellent electrochemical performances. This approach opens up a new avenue for the targeted design of nanostructured materials, where co-location of the desired metals in a single starting material shortens reaction times and temperatures since there is a decrease in diffusional energy requirements usually needed for these reactions to proceed.