Electrocatalytic properties of an iron organometallic complex and its role in the reduction of nitroaromatic compounds
Open Access
Author:
Miller, Joshua
Area of Honors:
Chemical Engineering
Degree:
Bachelor of Science
Document Type:
Thesis
Thesis Supervisors:
Michael John Janik, Thesis Supervisor Ali Borhan, Thesis Honors Advisor
Keywords:
electrocatalysis density functional theory nitroaromatic compounds iron organometallic complex
Abstract:
The electrochemical properties and electrocatalytic activity of an iron organometallic
complex were investigated using Density Functional Theory (DFT) methods. The complex was
studied for the electrocatalytic reduction of nitroaromatic compounds. The complex contains a
central iron atom bound to two chelated ligands, each containing two nitrogen atoms and one
oxygen atom connected to iron. In the most oxidized state of the complex, the iron lacks an open
coordination site for substrate binding. Upon addition of an electron and proton to a nitrogen on
one of the ligands, an iron-oxygen bond dissociates, leading to the ligand shifting away from the
iron. Five atoms remain bound to the iron, meaning there is an open coordination site. This
freeing of a coordination site allows an inner-sphere mechanism to take place for the
electrocatalytic reduction of nitroaromatics, namely nitrobenzene and TNT. Complexation of
nitrobenzene with the catalyst provided energetic stabilization. The inner-sphere catalytic
mechanism for nitrobenzene reduction mostly proceeded downhill energetically, with the initial
reduction of the catalyst to free a coordination site being the rate-limiting step. TNT
electrocatalytic reduction by the iron organometallic complex followed a similar pattern, with the
removal of OH from the catalyst being the rate-limiting step.
