In Situ Spectroscopic Studies of NH 3 Oxidation of Fe-Oxide/Al 2 O 3 .

Simple temperature-regulated chemical vapor deposition was used to disperse iron oxide nanoparticles on porous Al 2 O 3 to create an Fe-oxide/Al 2 O 3 structure for catalytic NH 3 oxidation. The Fe-oxide/Al 2 O 3 achieved nearly 100% removal of NH 3 , with N 2 as a major reaction product at temperatures above 400 °C and negligible NO x emissions at all experimental temperatures. The results of a combination of in situ diffuse reflectance infrared Fourier-transform spectroscopy and near-ambient pressure-near-edge X-ray absorption fine structure spectroscopy suggest a N 2 H 4 -mediated oxidation mechanism of NH 3 to N 2 via the Mars-van Krevelen pathway on the Fe-oxide/Al 2 O 3 surface. As a catalytic adsorbent-an energy-efficient approach to reducing NH 3 levels in living environments via adsorption and thermal treatment of NH 3 -no harmful NO x emissions were produced during the thermal treatment of the NH 3 -adsorbed Fe-oxide/Al 2 O 3 surface, while NH 3 molecularly desorbed from the surface. A system with dual catalytic filters of Fe-oxide/Al 2 O 3 was designed to fully oxidize this desorbed NH 3 to N 2 in a clean and energy-efficient manner.