DFT Study of Methanol Adsorption on Defect‐Free CeO2 Low‐Index Surfaces. Issue 16 (18th July 2019)

• Record Type: Journal Article
• Authors: Liu, Zhao; Sorrell, Charles C.; Koshy, Pramod; Hart, Judy N.
• Is Part Of: Chemphyschem. Volume 20:Issue 16(2019)
• Page Start: 2074
• Page End: 2081
• Publication Date: 2019-07-18
• Subjects: ceria -- density functional theory calculations -- hydrogen production -- low-index surfaces -- methanol adsorption; Chemistry, Physical and theoretical -- Periodicals; 541.05
• DOI: 10.1002/cphc.201900583
• Languages: English
• ISSNs: 1439-4235

Abstract

Abstract: Methanol decomposition is a promising method for hydrogen production. However, the performance of current catalysts for this process is not sufficient for commercial applications. In this work, methanol adsorption on the CeO2 low‐index surfaces is studied by density functional theory (DFT). The results show that methanol always dissociates spontaneously on the (100) surface, whereas dissociation on the (110) surface is site‐selective; dissociation does not occur at all on the (111) surface, where only weak physisorption is found. The results confirm that surfaces with higher energies are more catalytically active. Analysis of the surface geometries shows that the dominant factors for the dissociation of methanol are the degree of undercoordination and the charges of the surface ions. The adsorption energy of each methanol molecule decreases with increasing coverage and there is a transition threshold between dissociative and associative adsorption. The present work indicates that a strategy to design catalysts with high activity is to maximize exposure of surfaces on which the ions have a high degree of undercoordination and a strong tendency to donate/accept electrons. The results demonstrate the importance of appropriately selecting and controlling exposed facets and particle morphology for optimizing catalyst performance. Abstract : Dissociate or not ? Methanol adsorption on three low‐index ceria surfaces is studied by means of DFT calculations. It is found that methanol spontaneously dissociates on the (100) surface, whereas dissociation on the (110) surface is site‐selective; dissociation does not occur at all on the (111) surface. The results confirm that surfaces with higher energies exhibit higher catalytic activity. The different degrees of undercoordination and charges of the surface ions on the three surfaces result in different catalytic performance.