以理論計算探討一氧化碳分子於Au_1/ZrO_2(111)材料上的氧化反應

Theoretical Studies of CO Oxidation Reactionon Au_1/ZrO_2(111) Surface

劉啟佑(Chi-You Liu) ； 張鈞智(Chun-Chih Chang)

《化學》 78卷2期 (2020/06) Pp. 145-154

https://doi.org/10.6623/chem.202006_78(2).003

摘要

我們應用密度泛函理論（DFT）來研究CO在Au/ZrO_2(111)和具有氧空缺的Au/ZrO_2(111)-vac表面上的氧化反應機構。利用Nudged Elastic Band（NEB）方法推導了CO在potential-energy surfaces的氧化轉變結構。Au/ZrO_2(111)和Au/ZrO_2(111)-vac表面上的CO分子吸附能分別為-0.98 eV和-1.14 eV。在Au/ZrO_2(111)（E_a=0.94 eV,ΔH=-2.01 eV）和Au/ZrO_2(111)-vac（E_a=1.48 eV,ΔH=-2.93 eV）表面上的CO氧化都是可被進行的。此外，由於Au/ZrO_2(111)-vac中的Zr原子會因Au原子吸附而被活化，這也表示Au/ZrO_2(111)-vac與Au/ZrO_2(111)相比之下是有更優良的催化性能。為了理解催化劑及其吸附物之間的相互作用，我們同時也計算了電子性能，包含Local Density of States（LDOS）與Bader Charge分析，以支持所有這些結果的證據。

關鍵字

DFT計算 ； 一氧化碳 ； 氧化反應 ； 二氧化鋯

並列摘要

We applied density-functional theory (DFT) to investigate the reaction mechanism of CO oxidation on Au/ZrO_2(111) and Au/ZrO_2(111)-vac (with oxygen vacancies) surfaces. The transition structures of the CO oxidation on the potential-energy surfaces were derived with the nudged-elastic-band (NEB) method. The adsorption energies of CO molecules on the Au/ZrO_2(111) and Au/ZrO_2(111)-vac surfaces are -0.98 eV and -1.14 eV, respectively. The CO oxidation on Au/ZrO_2(111) (E_a = 0.94 eV, ΔH= -2.01 eV ) and Au/ZrO_2(111)-vac (E_a = 1.48eV, ΔH = -2.93 eV) surfaces are both feasible. Furthermore, compared with Au/ZrO_2(111) systems, the Zr atoms of the Au/ZrO_2(111)-vac would be activated by the adsorption of Au atom, implying the Au/ZrO_2(111)-vac system exhibits advantageous catalysis performance. To understand the interaction between catalysts and their adsorbates, we simultaneously calculated the electronic properties including the local densities of states and Bader charge analysis to support all evidence of these results.

並列關鍵字

DFT calculation ； CO oxidation ； ZrO_2