Announcing the Final Examination of Ms. Lorianne R. Shultz-Johnson for the degree of Doctor of Philosophy
The development of efficient, sustainable, and selective heterogeneous catalysts for nitro and azo-reductions, as well as photocatalytic oxidations, span importance in industry, agriculture, pharmaceuticals, and the environment. Thus, the development of robust, sustainable heterogeneous catalysts and elucidation of their mechanisms has become a critical area of research. Still, there are several significant challenges in these catalyst promoted reactions: (1) the current benchmark method for comparing catalytic activity does not account for chemoselectivity across different substrate patterns, (2) many of the most-active catalysts are based on precious metals which makes large scale implementation cost-prohibitive; (3) their structure-reactivity relationships are not well defined and, (4) the mechanisms of these probe reactions and impacting parameters are not well-elucidated, thus impeding the understanding-based design of better catalysts.
We address some of these limitations by providing an understanding-based approach to discover and investigate sustainable, earth-abundant catalysts for reduction and photocatalytic reactions. To improve the overall process of screening catalyst candidates, the limitations of the current screening protocol are presented; furthermore, an alternative, improved protocol using a nitrophenol cocktail solution is offered, assessed, and supported. To improve sustainability and recoverability of thermal catalysts, we have produced a copper-oxide based catalyst system supported on nickel foam that has reactivity for reduction reactions competitive with previously reported noble metal-based systems. This structure-activity relationships for copper oxide catalysts were then systematically studied to disentangle impact of surface defects, metal oxidation state, bandgap, size and surface properties.
Committee in Charge: Titel Jurca (Chair), Melanie Beazley, Michael Hampton, Lei Zhai, Fudong Liu
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