The synergistic effect in Co–Ce oxides for catalytic oxidation of diesel soot

Abstract

Oact: active oxygen species. C*[O]: carbon–oxygen intermediate. The synergistic effect in Co–Ce catalyst leads to more oxygen vacancies and enhanced redox ability, thus assisting soot combustion.

Effect of Residual Na+ on the Combustion of Methane over Co3O4 Bulk Catalysts Prepared by Precipitation

“…The pore size distributions, shown in Figure 3, also evidenced a shrinking effect over the mean pore diameter when cobalt oxide is contaminated with residual sodium. These effects have already been reported in other studies regarding the doping of Co3O4 catalysts with other metallic elements [27,28]. It must be noticed that all those variations were originated by a relatively low bulk concentration of sodium (0.4 wt%).…”

Design of active NiCo2O4‐δ spinel catalyst for abatement of CO‐CH4 emissions from CNG fueled vehicles

“…Co 3 O 4, homogeneous spinel with variable valence states (Co 2+ , Co 3+ , and Co 4+ ) of metal cations is a promising candidate for oxidation due to its multifold surface lattice oxygen anions . The substitution of Co 2+ cation in the normal spinel with the other divalent cations (Ni 2+ ) is a promising opportunity to increase the catalytic activity due to the presence of highly oxidized redox couples (Co 3+ /Co 2+ and Ni 3+ /Ni 2+ ) as well as the synergistic effect of two metals . The nickel cobaltite (NiCo 2 O 4 ) is known as mixed spinel oxide with general formula (A 1‐x B x )[A x B 2‐x ]O 4 .…”

Reactive calcination route for synthesis of active Mn–Co 3 O 4 spinel catalysts for abatement of CO–CH 4 emissions from CNG vehicles

“…24,25 The substitution of Co 21 cation in the normal spinel with the other divalent cations (Ni 21 ) is a promising opportunity to increase the catalytic activity due to the presence of highly oxidized redox couples (Co 31 /Co 21 and Ni 31 / Ni 21 ) as well as the synergistic effect of two metals. [26][27][28] The nickel cobaltite (NiCo 2 O 4 ) is known as mixed spinel oxide with general formula (A 1-x 4 . The lattice of spinel NiCo 2 O 4 imparts extra stability under various catalytic reaction conditions so that it has sustained activity for longer periods whereas; individual metal oxides lose their catalytic activity rapidly due to sintering and carbonaceous deposition.…”