In Situ Spectroscopic Studies of NH3 Oxidation of Fe-Oxide/Al2O3

Simple temperature-regulatedchemical vapor deposition was usedto disperse iron oxide nanoparticles on porous Al2O3 to create an Fe-oxide/Al2O3 structurefor catalytic NH3 oxidation. The Fe-oxide/Al2O3 achieved nearly 100% removal of NH3, withN(2) as a major reaction product at temperatures above 400 & DEG;C and negligible NO x emissions atall experimental temperatures. The results of a combination of insitu diffuse reflectance infrared Fourier-transform spectroscopy andnear-ambient pressure-near-edge X-ray absorption fine structurespectroscopy suggest a N2H4-mediated oxidationmechanism of NH3 to N-2 via the Mars-vanKrevelen pathway on the Fe-oxide/Al2O3 surface.As a catalytic adsorbent an energy-efficient approach to reducingNH(3) levels in living environments via adsorption and thermaltreatment of NH3 no harmful NO x emissions were produced during the thermal treatment of theNH(3)-adsorbed Fe-oxide/Al2O3 surface,while NH3 molecularly desorbed from the surface. A systemwith dual catalytic filters of Fe-oxide/Al2O3 was designed to fully oxidize this desorbed NH3 to N-2 in a clean and energy-efficient manner.