Materials Engineering Thesis Defense
Philip Mantos will defend his master's thesis in the Materials Engineering Department. His talk is "Interaction Mechanism of Transition Metal Phthalocyanines on Different Catalytic Supports, Graphene, and Transition Metal Nitride."
The goal of this work is to characterize the interactions between transition metal phthalocyanine (TMPc’s) and supporting materials that are both optically and electronically active. Here we studied copper phthalocyanine (CuPc) and cobalt phthalocyanine (CoPc) as the catalytic TMPc materials because of their applications in many important reactions such as, electrochemical carbon dioxide reduction, oxygen reduction reaction and methane to methanol conversion. We studied the interaction of the above TMPc’s with two different catalytic supports such as graphene and titanium nitride. Graphene is often considered as a viable support for TMPc molecules because of strong electronic interaction among them and highly tunable surface and a large surface to volume ratio of graphene. Titanium nitride (TiN) is an emerging supporting material which gets significant attention due to many favorable properties such as high stability, tailorable stoichiometry, photothermal properties and high thermal conductivity and electron mobility . The specific aims were: First, synthesize and characterize the structures and the compositions of TMPC catalytic compounds supported on both graphene and TiN. Second, understand the electronic interaction between TMPc’s and their supporting structures using X-ray Photoelectron Spectroscopy (XPS) and Photo-Emissive Electron Microscopy (PEEM). Third, to synthesize transition metal-oxo complex on TMPc under mild conditions. We have successfully synthesized and characterized the graphene/TMPc and TiN/TMPc composites. We found that the adsorption of TMPc’s onto the graphene renders P type doping effect where the graphene donated electrons to the TMPc structure. On the other hand, TiN had an N type doping effect where it caused an electron deficiency in the TMPc’s. Finally, we could generate both cobalt-oxo complexes and copper-oxo complexes using hydrogen peroxide as a reactant. Both cobalt-oxo species and copper-oxo species could be important for a number of oxidative transformation processes e.g., water oxidation and oxygen atom transfer reactions and C-H bond breaking.