Effect of External Electric Field on Methane Conversion on IrO₂(110) Surface: A Density Functional Theory Study

Abstract

Catalytic conversion of methane to value-added chemicals is a promising application for gas versatility. In this work, we have investigated the methane oxidation over oxygen-rich IrO2 (110) surface by DFT calculations, as IrO2 is reported to be an effective catalyst for activating the C–H bond of methane. Compared to the methane reaction on the surface of stoichiometric IrO2 (110), the reaction barrier for each step of forming formaldehyde on the oxygen-rich IrO2 (110) is small. The calculations show that formaldehyde formation is the most favorable route in methane oxidation, but this process is limited by the high desorption energy of formaldehyde. To modify the reactivity of IrO2 (110), we conducted a study of the influence of an external electric field on the methane conversion reaction. The calculations show that the effects of external electric field on methane dehydrogenation and C–O coupling reactions are not so apparent. However, it is found that the desorption energy of the adsorbates can be regulated by applying an external electric field. Our study indicates that the use of an external electric field is crucial in regulating the catalytic reaction, and especially the application of a positive electric field promotes the oxidation of methane to formaldehyde over oxygen-rich IrO2 (110) surface.

Oriented external electric fields regulating the oxidation reaction of CH4 catalyzed by Mn‐corrolazine

“…Then, when the external electric fields are applied, the Mulliken charges of the C atom of CH 4 are −0.88, −1.08, and −0.72 |e − | under fields of +0.015, 0.0, and −0.015 a.u. for F z1 (−1.01, −0.88, −0.76 |e − | for F z2 ), respectively, which is consistent with the work of Jiang et al [ 55 ] that the positive external electric field enhances the electron transfer in the positive Z‐direction, and the negative external electric field weakens the electron transfer in the positive Z‐direction.…”

Catalytic Oxidation of Methane to Oxygenated Products: Recent Advancements and Prospects for Electrocatalytic and Photocatalytic Conversion at Low Temperatures

“…Recently, through DFT calculations, Yeh et al demonstrated that a positive electric field enhanced the oxidation of CH 4 to HCHO by O 2 over the oxygenrich (110) surface of IrO 2 . [183] External electric field can suppress methane reforming temperature considerably. [184] In addition, plasma can oxidize methane as can be seen in the following review.…”

External electric field: a new catalytic strategy for the anti-Markovnikov hydrohydrazination of parent hydrazine

“…The external electric eld (EEF), which is well-known as a green and effective metal-free catalyst, is emerging into one's insight. [50][51][52][53] This "invisible catalyst", by now, has been investigated by numerous theoretical studies [54][55][56][57][58][59][60][61][62][63][64][65] and further conrmed by experiments for the Diels-Alder reaction in 2016. 66 These investigations manifested that EEF not only inuence the atom charge but also catalyzes the chemical reactions.…”