John Di Iorio
Graduate Research AssistantAdvised by Professor Rajamani Gounder
Xtrudx Technologies Inc., Process Engineering Intern (Summer 2010 – Summer 2013)
Allan Research Group – University of Washington, Undergraduate Research Assistant (May 2010 – June 2013)
- Henry K. Benson Endowment in Chemical Engineering Scholarship (2011 – 2013)
Project Description (high level)
Nitrogen oxide (NOx) compounds are greenhouse gases and pollutants generated by industrial power plants and lean-burn diesel engines, and have been linked to acid rain and smog formation and to various human respiratory ailments. I work on the synthesis and characterization of metal-exchanged zeolite catalysts for the selective catalytic reduction (SCR) of these harmful NOx compounds to environmentally benign N2 and H2O products. The zeolites that I work with have a mixture of Lewis and Bronsted acid sites and I am trying to determine the role of each site in the SCR mechanism. The number of Lewis and Bronsted sites can be varied during zeolite synthesis or by post-synthetic modification. The structure and behavior of the zeolites are determined using a variety of characterization techniques available within the Purdue Catalysis Center and in shared facilities at Purdue. Rates of NOx SCR are measured on a gas-phase flow reactor connected to online gas chromatographs, mass spectrometers, and gas infrared analyzers that let us examine the product composition under different reaction conditions.
Project Description (detailed)
My research focuses on the selective catalytic reduction (SCR) of NOx compounds over Cu-exchanged zeolites, primarily of the chabazite (CHA) topology. Particular interest is placed on the synthesis of zeolites with varying composition and structure, which will be used in fundamental characterization and kinetic studies that probe the active sites responsible for catalyzing NOx SCR. It is known that both Lewis acidic metal sites and Bronsted acid sites exist in these zeolites, but their individual contributions to SCR reactivity remain an area of active investigation. The structure of the zeolites and the active sites will be examined in detail using characterization methods including X-ray diffraction (XRD), atomic adsorption (AA), N2 and Ar physisorption, basic amine titration and temperature-programmed desorption (TPD) experiments, UV-Visible spectroscopy, and probe reactions of metal and acid sites. These Cu-exchanged zeolite materials, which are synthesized in-house, will also be used in kinetic studies of NOx SCR and NO oxidation.