Probing the Electric Field Effect on the Catalytic Performance of Mn-Doped Graphene to CO Oxidation

Abstract

The electric field is an effective route to tune the performance of catalysts. Here, we have probed the reaction mechanism of CO oxidation on Mn-doped graphene (Mn-Gr), the effect as a result of the externally applied electric field, and provided a theoretical understanding of the rule by density functional theoy (DFT) calculation. On the basis of DFT calculations, we suggest that electric field has significant impact on the catalytic performance of CO oxidation on Mn-Gr. The reaction barriers for CO2 formation decrease with increasing CO/O2 adsorption on Mn-Gr as the electric field decreases from +0.5 to −0.75 V/A, leading to a greater activation of the O–O bond and then accelerate the CO2 formation. However, strong binding between CO2 and Mn-Gr under a larger positive or negative electric field would result in CO2 desorption difficult and hinder the catalyst regeneration. Therefore, it is proposed that −0.50 F/A is more appropriate for CO oxidation on Mn-Gr with a lower determined reaction barrier of 0....