Silver‐Doped Cobalt (Magnesium) Aluminum Mixed Metal Oxides as Potential Catalysts for Nitrous Oxide Decomposition

Abstract

AbstractN2O is a potent greenhouse gas released among others in nitric and adipic acid production as well as from stationary and mobile combustion sources. A catalytic decomposition is highly attractive but requires catalysts active over a broad temperature range and in the presence of inhibiting compounds such as NO and O2. Ag‐doped Co‐(Mg)‐Al‐Ox mixed metal oxides obtained by the coprecipitation of metal nitrate precursors followed by calcination were evaluated as potential catalysts for N2O decomposition (deN2O) also in the presence of NO and/or O2. Ag integration during synthesis proved to be essential for superior catalytic activity. The catalyst with the optimum composition, AgCo3Al‐Ox (Co/Al=3:1 mol %, 1.0 wt % Ag), achieved full N2O conversion at 350 and 450 °C under N2O/N2 and N2O/NO/O2/N2 conditions, respectively. Catalyst characterization, with a focus on H2 temperature‐programmed reduction and X‐ray photoelectron spectroscopy, evidenced that abundant Ag0 on the surface of (1.0–2.8 wt %)AgCo3Al‐Ox enhanced the reduction of cobalt spinels to enable the superior catalytic performance.