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.

Automated summary

Temperature-regulated chemical vapor deposition was used to disperse iron oxide nanoparticles on porous Al2O3 to create a catalytic Fe-oxide/Al2O3 structure for NH3 oxidation. The Fe-oxide/Al2O3 achieved almost complete NH3 removal, with N2 as the main product and no detectable NOx emissions at all temperatures. The results of spectroscopic analysis suggest an NH3 oxidation mechanism mediated by N2H4 on the Fe-oxide/Al2O3 surface. A dual catalytic filter system was designed using Fe-oxide/Al2O3 to fully oxidize NH3 to N2 in a clean and energy-efficient manner.