Klaas Lena, Bulfin Brendan, Kriechbaumer Dorottya, Roeb Martin, Sattler Christian
Deutsches Zentrum für Luft- und Raumfahrt - DLR/German Aerospace Center, Institute of Future Fuels, Linder Höhe, 51147 Cologne, Germany.
Faculty of Mechanical Engineering, Chair for Solar Fuel Production, RWTH Aachen University, 52062 Aachen, Germany.
Phys Chem Chem Phys. 2023 Mar 29;25(13):9188-9197. doi: 10.1039/d3cp00267e.
CaMnO-based perovskites find application in a variety of thermochemical cycles, oxygen partial pressure adjustment, chemical looping processes, and thermochemical energy storage. The applicability of these materials is governed by their thermodynamic and kinetic properties. Therefore, tunability of these properties is desirable to adapt the material to the required conditions. In this study, the effect of Sr content in CaSrMnO on thermodynamics and kinetics is investigated by thermogravimetric analysis. The thermodynamics are measured in the temperature range of 873 K to 1473 K with oxygen partial pressures of 1 × 10 bar to 0.8 bar. The oxidation kinetics were characterized in the temperature range from 473 K to 673 K with oxygen partial pressures of 0.01 bar to 1 bar. The reduction kinetics were very rapid in the temperature range of 873 K to 1023 K, with the measured rates limited by the constraints of the measurement device. The results show that with increasing Sr content the structural changes of the material decrease the reduction enthalpy and the oxidation activation energy. This not only leads to a tunability of material properties, but can also be used to predict changes of these properties when only the structural changes are known.
