Cobalt-based ferrites as efficient redox materials for thermochemical two-step CO₂-splitting: enhanced performance due to cation diffusion

Abstract

The addition of CoO into CoFe2O4 triggers bulk cation diffusion and thereby leads to higher CO2 splitting reactivity.

Remarkable solar thermochemical CO2 splitting performances based on Ce- and Al-doped SrMnO3 perovskites

“…Thus, the reaction kinetic model of solar thermochemical CO 2 splitting can be analyzed and obtained by fitting solid-state kinetic theory with the master plot methods. 64,65 Table 3 lists four solid-state reaction models (F1, F2, D1, and D2) in this work, 66 and the comparison of normalized rate data at 1100 °C with various reaction model data is presented in Fig. 9.…”

“…9b), the normalized CO production rate has the same trend as the second order reaction model (F2) at first, and subsequently, when 0.5> α > 0.2, the reaction mechanism model begins to transform to the D1 model, and then when α > 0.5, the CO 2 splitting reaction is more inclined to the two-dimensional diffusion model (D2), showing that the oxidation reaction may occur in crystal lattices, in which molecular motion depends on lattice defects. 64,65 Compared to undoped SrMnO 3 , the kinetic reaction mechanism of SCMA20 has mainly changed from F1 to F2, indicating that the kinetic reaction rate can be enhanced by the increase of the reaction order n . Therefore, the ultrahigh CO yield and fast kinetics of SCMA20 can be mainly attributed to the transition from the first-order reaction (F1) to the second-order reaction (F2).…”

“…Thus, the reaction kinetic model of solar thermochemical CO 2 splitting can be analyzed and obtained by tting solid-state kinetic theory with the master plot methods. 64,65 9. F1 and F2 models are dened as an instantaneous nucleation and unidimensional shape and bidimensional shape, respectively.…”

Ca- and Ga-Doped LaMnO3 for Solar Thermochemical CO2 Splitting with High Fuel Yield and Cycle Stability

“…Up until now, tens of metal oxides have been investigated for solar thermochemical CO 2 splitting, such as Fe 3 O 4 /FeO, ZnO/Zn, 10 SnO 2 /SnO, 11 ABO 3 /ABO 3−δ (perovskite), 12−14 CeO 2 /Ce 2 O 3 , 15−18 and ferrite 19…”

“…Up until now, tens of metal oxides have been investigated for solar thermochemical CO 2 splitting, such as Fe 3 O 4 /FeO, ZnO/Zn, SnO 2 /SnO, ABO 3 /ABO 3−δ (perovskite), − CeO 2 /Ce 2 O 3 , − and ferrite catalytic systems. Stoichiometric redox pairs such as ZnO/Zn and SnO 2 /SnO have high oxygen exchange capacities, but they are volatile.…”