It has to be mentioned that we consider the thermodynamic feasible conversion, which represents the upper bound. For instance, Alam et al. assumed a conversion of 60% (the authors called it efficiency) at a stoichiometric H2/CO2 ratio of 4 based on kinetic experiments conducted by Falbo et al. . In equilibrium, we obtain a significantly higher conversion of approx. 94% at the stoichiometric feed ratio. However, achieving conversions close to chemical equilibrium is generally viable and a matter of appropriate reactor design as illustrated by Bremer et al. for adiabatic and polytropic operation strategies .