Nitrous Oxide Decomposition Over MCO3–Co3O4 (M = Ca, Sr, Ba) Catalysts

Abstract

In this paper, nitrous oxide decomposition over a series of MCO 3 -Co 3 O 4 (M = Ca, Sr, Ba) catalysts having M/Co ratios of 0.1-0.4 has been studied. The various catalysts were characterized using thermal (TGA, DTA), XRD, IR and N 2 sorption techniques. N 2 O decomposition activity was found to be dependent on the type of the alkaline earth cation, the M/Co ratio, cobalt oxide crystallites sizes, and the calcination temperature.

Green synthesis of Co3O4nanoparticles viaAspalathus linearis: Physical properties

“…While the Raman mode at 684.5 cm −1 is attributed to characteristics of the octahedral sites A 1g , the E g, and F 2g modes are related to the combined vibrations of tetrahedral site and octahedral oxygen motions (23). The average shift of Δν∼5 cm -1 may be attributed to size effects or surface stress/strain.…”

“…The precipitate was then separated from the aqueous extract, first by decanting then by centrifuging at 1000 rpm 3 times for 10 min each over successive additions of de-ionized water to wash the precipitate of any residual aqueous extract. As the synthetized oxides-based nanoparticles by green process are generally amorphous, an annealing was necessary to induce an effective crystallization (23)(24)(25)(26)(27)(28)(29)(30)(31)(32). In this case, the asobtained centrifuged precipitate was heated at 90°C for 90 min to remove bio-compounds in excess.…”

Rare Earth-Promoted Nickel Oxide Nanoparticles as Catalysts for N2O Direct Decomposition

“…The reported N 2 O decomposition mechanism on various metal oxide catalysts involves the following steps: (i) N 2 O adsorption via electron donation from the catalyst surface to the adsorbate; (ii) N-O bond destabilization, which leads to its scission and the liberation of N 2 molecule and the formation of an adsorbed O´species; and (iii) recombination of two O´species and desorption of one oxygen molecule. Thus, this reaction requires the coexistence of a redox couple on the catalysts surfaces, such as Co 2+ -Co 3+ [7][8][9][10][11][12][13][14][15][16]43], Cu + -Cu ++ [21,22], Ni 0 -Ni 2+ [23,24]. In this respect, our XPS analysis (Figure 7) revealed the presence of Ni 0 -Ni 2+ redox couple on the surfaces of bare NiO and Gd-promoted NiO.…”

Optimization of Cs content in Co–Mn–Al mixed oxide as catalyst for N2O decomposition

“…According to reported studies [2,20,[22][23][24], mechanism of the N 2 O catalytic decomposition can be described as a charge donation from the catalyst to the anti-bonding orbital of N 2 O, which destabilizes the N-O bond, leading to scission. Therefore, electron charge transfer from the metal ion to the N 2 O molecule is a crucial step for N 2 O catalytic decomposition [24].…”