Density Functional Theoretical Studies on the Methanol Adsorption and Decomposition on Ru（0001） Surfaces

• Published in: 高等学校化学研究：英文版 2016 (2), p.234-241
• Main Author: LIU Jianhong LV Cunqin JIN Chun GUO Yong WANG Guichang
• Format: Article
• Language: English
• Subjects: Ru（0001）; 吸附; 和分解; 密度泛函理论; 甲醇; 脱氢反应; 表面; 覆盖面
• ISSN: 1005-9040; 2210-3171

Periodic density functional theory（DFT） calculations are presented to describe the adsorption and decomposition of CH3OH on Ru（0001） surfaces with different coverages, including p（3 ×2）, p（2×2）, and p（2× 1） unit cells, corresponding to monolayer（ML） coverages of 1/6, 1/4, and 1/2, respectively. The geometries and energies of all species involved in methanol dissociation were analyzed, and the initial decomposition reactions of methanol and the subsequent dehydrogenations reactions of CH3O and CH2OH were all computed at 1/2, 1/4, and 1/6 ML coverage on the Ru（0001） surface. The results show that coverage exerts some effects on the stable adsorption of CH30, CH2OH, and CH3, that is, the lower the coverage, the stronger the adsorption. Coverage also exerts effects on the initial decomposition of methanol. C-H bond breakage is favored at 1/2 ML, whereas C-H and O--H bond cleavages are preferred at 1/4 and 1/6 ML on the Ru（0001） surface, respectively. At 1/4 ML coverage on the Ru（0001） surface, the overall reaction mechanism can be written as 9CH3OH ,3CH30＋6CH2OH＋9H ,6CH20＋3CHOH＋18H , 7CHO＋COH＋CH＋OH＋26H → 8CO＋C＋O＋36H.