DFT-D2 simulations of water adsorption and dissociation on the low-index surfaces of mackinawite (FeS)
DFT-D2 simulations of water adsorption and dissociation on the low-index surfaces of mackinawite (FeS)
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DOI：
10.1063/1.4947588
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发表时间：
2016-05-07
影响因子：
4.4
通讯作者：
de Leeuw, N. H.
中科院分区：
文献类型：
--
作者：
Dzade, N. Y.;Roldan, A.;de Leeuw, N. H.
利用离散/校正密度泛函理论（DFT-D2）计算，研究了水在mackinawite（层状FeS）表面的吸附和解离。测定了水及其解离产物在FeS{001}、{011}、{100}和{111}表面上的催化活性位点，并利用爬升图像轻推弹性带技术计算了水解离反应的热力学和动力学。结果表明，水及其解离产物在最不稳定的FeS{111}表面上吸附更强，表面上存在低配位阳离子，而在最稳定的FeS{001}表面吸附最弱。吸附能大小依次为FeS{111} > FeS{100} > FeS{011} > FeS{001}。与FeS{111}表面对水及其解离产物的优越反应性相一致，我们计算的热化学能和激活势垒表明，水的解离反应将优先发生在具有{111}取向的FeS纳米颗粒表面。这些发现提高了我们对不同的FeS表面结构和相对稳定性如何决定其对水吸附和解离的反应性的理解。AIP出版社出版。
The adsorption and dissociation of water on mackinawite (layered FeS) surfaces were studied using dispersion/corrected density functional theory (DFT-D2) calculations. The catalytically active sites for H2O and its dissociated products on the FeS {001}, {011}, {100}, and {111} surfaces were determined, and the reaction energetics and kinetics of water dissociation were calculated using the climbing image nudged elastic band technique. Water and its dissociation products are shown to adsorb more strongly onto the least stable FeS{111} surface, which presents low-coordinated cations in the surface, and weakest onto the most stable FeS{001} surface. The adsorption energies decrease in the order FeS{111} > FeS{100} > FeS{011} > FeS{001}. Consistent with the superior reactivity of the FeS{111} surface towards water and its dissociation products, our calculated thermochemical energies and activation barriers suggest that the water dissociation reaction will take place preferentially on the FeS nanoparticle surface with the {111} orientation. These findings improve our understanding of how the different FeS surface structures and the relative stabilities dictate their reactivity towards water adsorption and dissociation. Published by AIP Publishing.