Catalytic conversion of methane to alcohol is an attractive process as alcohols are easier to store and transfer, and can be used as a feedstock to various value-adding products via a consecutive chemical process. Although methanol is mainly synthesized steam reforming of methane to syngas, alternative routes have been investigated as the process operates in energy consuming harsh conditions. Electrochemical systems in ambient conditions is potentially a fine alternative. Few reports exist on electrochemical methane conversion systems, and as underlying mechanisms are hard to find by experimental means only. Even fewer reports propose validated mechanisms. In this research, we use Density Functional Theory plus Hubbard U(DFT+U) calculations and Nudged Elastic Band (NEB) method to propose and validate mechanisms of electrochemical reactions in oxide bifunctional nanocomposite catalysts iron oxide-zirconia and Nb-doped nickel oxide-zirconia as a medium to convert methane to higher order alcohols. Under basic conditions with carbonate anions as the main oxygen source, in Fe2O3-ZrO2 and NiO-ZrO2 systems, there exist methane-to-methanol/methane-to-ethanol pathways. We show that these pathways are realistic reactions given moderate electrochemical potentials. We demonstrate that aqueous basic conditions potentially alter the reaction pathway itself from conventional gas phase reactions that have previously been reported. The precise mechanism of oxygen transfer involving zirconium oxide support will also be covered.

First principle calculations on electrochemical conversion of methane to alcohols on iron oxide-zirconia and Nb-doped nickel oxide-zirconia composites

2019 Spring National Meeting

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.