Abstract
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.