Reductive removal of gaseous nitrous oxide by activated carbon with metal oxide catalysts

Abstract

The efficient reductive decomposition of gaseous nitrous oxide (N₂O) from industrial effluents is of practical importance in abating greenhouse gas emissions. In the present study, active carbon (AC) has been chosen as both a reductive agent and a catalyst support. Dozens of AC-based catalysts with different kinds and amounts of metal oxide have been prepared under various conditions and characterized. The performances of Cu-containing AC have been studied at varying gas flow rates, Cu contents, and calcination temperatures. N₂O in a gas mixture (42% N₂O, 58% N₂) was found to be completely removed by Cu-loaded AC (9 wt% Cu, calcined at 400 °C) at 325 °C with a GHSV of 2293 h⁻¹. This process is viable by virtue of the low cost of AC and easier manipulation and process control in comparison with alternative methods employing reductive gases such as hydrogen and ammonia.