Abstract:

The goal of our research at Artificial Photosynthesis Program at Brookhaven National Laboratory is to gain a fundamental understanding of processes involved in the chemical conversion of solar energy. Together with our collaborators, we perform coordinated experimental and theoretical studies to address the scientific challenges associated with efficient coupling of light absorption, photoinduced electron-transfer processes, and chemical transformations, together with managing proton movement and charge leveling in catalysts. Among oxidative chemical transformations, we devote significant attention to water oxidation because of its importance in both natural and artificial photosynthesis as the ideal source of electrons and protons. On the light driven reductive transformations thrust, we focus on electro- and photocatalytic reduction of CO2 and reversible H2 storage via CO2 hydrogenation and formic acid dehydrogenation reactions.

In this seminar, I will highlight how our detailed mechanistic studies of water oxidation by transition metal-based complexes enable the development of highly efficient catalysts by carefully controlling the factors that govern the critical 0-0 bond formation step. Moreover, our efforts on computational modeling of proton coupled electron transfer (PCET) reactivity and the effect of the solvent polarity and hydrogen-bonding ability on modification of the PCET mechanism for the stepwise and concerted pathways will be presented. Final part of my talk will focus on our recent mechanistic investigations of CO2 reduction catalytic cycles, and roles of second coordination sphere effects and added bases/acids.

Short Biography of the Speaker:

Dr. Mehmed Zahid Ertem received his B.S. degrees (2005) in Chemistry and Molecular Biology & Genetics (double-major) from Bogazici University. Following his graduation, he studied the mechanism of phosphate hydrolysis in aqueous solutions and enzyme active sites under supervision of Prof. Viktorya Aviyente and received his M.S. degree (2007) in Chemistry from Bogazici University. He completed his PhD. (2012) studies at University of Minnesota in Prof. Christopher Cramer’s group working on quantum chemical characterization of small molecule activation by transition metal complexes. He then moved to Yale University to pursue postdoctoral research (2012-2014) under supervision of Prof. John Tully and Prof. Victor Batista and expanded his research to computational modeling of enzymatic and heterogeneous catalysis. Following another postdoctoral research under guidance of Dr. James Muckerman at Brookhaven National Laboratory (BNL), he started independent career in 2016 as an Assistant Scientist in Artificial Photosynthesis Program at BNL Chemistry Division where he currently holds Scientist position.