Mechanistic Understanding of Methane Hydroxylation by Cu-Exchanged Zeolites

Methane direct conversion to methanol or methane hydroxylation by Cuexchanged zeolite catalysts through a stepwise approach is a promising process for fulfilling the increasing energy demand in the midst of declining fossil energy and unreadiness of renewable energy technologies. However, there are still many challenges hampering this process from yielding methanol with amount that meets industrial expectations. Therefore, understanding the mechanism of how the strong C–H bond of methane is cleaved and how methanol is formed only in the presence of a particular solvent could help optimizing the process or finding novel approaches. In this chapter, we overview the mechanistic understanding on the methane’s C–H cleavage through the homolytic hydrogen atom abstraction and evaluate the formation of methanol through a mechanism where a surface methoxy is formed as an intermediate species and a water molecule acts as a reactant or an assistant to form methanol through a hydrolysis or an indirect HO–CH3 rebound.