Molecular and material approaches to discovery of highly active and stable earth-abundant metal catalysts /

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Bibliographic Details
Author / Creator:Zhang, Teng, author.
Ann Arbor : ProQuest Dissertations & Theses, 2015
Description:1 electronic resource (193 pages)
Format: E-Resource Dissertations
Local Note:School code: 0330
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Other authors / contributors:University of Chicago. degree granting institution.
Notes:Advisors: Wenbin Lin Committee members: Michael D. Hopkins; Richard F. Jordan.
Dissertation Abstracts International, Volume: 77-02(E), Section: B.
Summary:The first part (Chapter 1) of this dissertation focuses on designing electrocatalysts for the water oxidation reaction. Developing electrocatalysts with low overpotential, good stability, and high turnover rates for water oxidation is one of the key challenges of water splitting process and solar fuel production. Inspired by the structure of natural oxygen evolution complex, we designed and synthesized a copper-bipyridine complex with pendant hydroxyl groups. The complex showed activity towards electrocatalytic water oxidation with an overpotential ~200 mV lower than the parent copper-bipyridine complex without hydroxyl groups. Experimental and theoretical studies indicated that the redox-active ligand was involved in the catalytic cycle and played a crucial role in lowering the overpotential.
The second part (Chapters 2-4) of this dissertation focuses on using metal-organic frameworks (MOFs) as a platform to design and develop novel catalysts for a variety of organic transformations. MOF catalysis has grown into an intensively studied research topic in recent years. In particular, MOFs enable isolation of catalytic active sites and lead to unprecedented activities and selectivities. We developed several series of MOF catalysts by taking advantage of the site-isolation effect to achieve novel catalytic performance. In Chapter 2, we synthesized two MOFs based on chiral Co(salen)-derived linkers, a catalyst for asymmetric ring opening of epoxides. We found that site-isolation in the MOF catalysts leads to different regio- and enantio-selectivities from their homogeneous analogs. In Chapter 3, we developed MOF catalysts based on Co(bpy) active species that can turnover more than two million times for alkene hydrogenation, one of the highest ever reported for earth-abundant metal catalysts. The same catalyst is also highly active for hydroboration of alkenes and ketones. Structural, spectroscopic and computational studies revealed a solution-inaccessible Co(bpy)(solvent)x species to be the catalyst. In Chapter 4, we developed a MOF catalyst based on salicylaldimine complexes of iron and cobalt which are also highly active for alkene hydrogenation. The catalysts exhibited turnover numbers up to more than one hundred thousand, and were recycled and reused for at least ten times. Further refinements of these MOF catalysts will lead to more active and selective catalysts for applications in practical catalysis.