This reaction exhibits an energy barrier of +97.0 kJ/mol (HSE06; for PBE +75.7 kJ/mol) and a total reaction energy of ΔE = +90.7 kJ/mol (HSE06; for PBE +62.0 kJ/mol). Considering that this energy barrier must be added to the energy barrier to reach 1 TS CH , we suggest that this reaction is unlikely to occur. In the third deactivation pathway, the reaction of methanol with an M site could lead to an iron-bound methoxy species FeOCH3 and water (ads). We find, that the reaction energy for this reaction is +4.7 kJ/mol (HSE06; for PBE -0.02 kJ/mol), making it an energetically slightly unfavorable but possible side reaction, considering the desorption energy of water into the gas phase is 34.1 kJ/mol. However, the so formed iron-methoxy species can be expected to be subject to hydrolysis due to the slightly higher relative energy of the iron-methoxy species with respect to the M site.