CO2 Adsorption on H2O-Saturated BaO(1 0 0) and Induced Barium Surface Dissociation

• Published in: Bulletin of the Korean Chemical Society Vol. 36; no. 1; pp. 11 - 16
• Main Authors: Kwon, Soonchul, Lee, Seung Geol, Chung, Eunhyea, Lee, Wang Ro
• Format: Journal Article
• Language: English
• Published: Weinheim Wiley-VCH Verlag GmbH & Co. KGaA 01.01.2015; Wiley‐VCH Verlag GmbH & Co. KGaA; 대한화학회
• Subjects: Adsorption; Barium oxide; Carbon dioxide; Density functional theory; Water; 화학
• ISSN: 1229-5949; 0253-2964; 1229-5949
• DOI: 10.1002/bkcs.10000

The aggregated H2O molecules tend to produce a hydrogen‐terminated surface, and then generate barium dissociation of the barium oxide (BaO) surface. The dissociated barium of the surface, driven by the high affinity of H2O to the surface, contributes to a reduction in basicity, which may gradually cause the reduction of CO2 adsorption performance. CO2 adsorption on a barium oxide (BaO) surface saturated with a monolayer of H2O molecules was studied; a monolayer of H2O molecules on the BaO surface exhibits nondissociative or dissociative adsorption. During the nondissociative reaction, a hydroxyl ion‐terminated surface is produced, resulting in the formation of barium hydroxide (Ba(OH)2) on the surface. The Ba(OH)2 from the substrate associates with the tightly bound CO2 molecule, resulting in the formation of barium carbonate (BaCO3). In contrast, during the dissociative H2O adsorption, a hydrogen‐terminated surface is produced, which strongly adsorbs CO2 molecules. The H2O molecules on a fully saturated BaO surface (containing multiple layers of H2O molecules) readily aggregate, and Ba dissociation takes place on the hydrated surface, possibly resulting in a surface containing Ba defects.