Periodic DFT Study on the Adsorption and Catalytic Desulfurization of Thiophene over VC(001) and VN(001) via Hydrogenation and Direct Pathways
Periodic DFT Study on the Adsorption and Catalytic Desulfurization of Thiophene over VC(001) and VN(001) via Hydrogenation and Direct Pathways
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DOI：
10.1021/acs.jpcc.5b10993
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发表时间：
2016-03-10
影响因子：
3.7
通讯作者：
de Alencastro, Ricardo Bicca
中科院分区：
文献类型：
--
作者：
de Souza, Eugenio Furtado;Ramalho, Teodorico C.;de Alencastro, Ricardo Bicca
基于超软赝势和平面波基组，采用周期性从头算密度泛函方法研究了噻吩在碳化钒和氮化钒立方面心（001）表面上的吸附和反应机理，并探讨了噻吩在加氢脱硫（HDS）、直接脱硫（DDS）和加氢脱硫（HYD）反应中的应用.此外，为了确定它们在吸附和脱硫过程中的作用，研究了吸附络合物的各种初始构型。我们的研究结果表明，环加氢并不一定导致噻吩脱硫的HYD途径的偏好。此外，由于吸附的表面和电子效应也进行了评估。我们已经发现，在理想条件下，钒的氮化物和碳化物表面呈现类似的活性超过噻吩的脱硫，在定性与实验一致。
Periodic ab initio DFT calculations based on ultrasoft pseudopotentials and a plane-wave basis set were carried out to shed some light on the adsorption and reaction mechanisms of thiophene over vanadium carbide and vanadium nitride cubic face-centered (001) surfaces and its implications for hydrodesulfurization (HDS), Direct (DDS) and hydrogenating (HYD) routes were considered for further desulfurization reactions. Furthermore, to identify their role in the adsorption and desulfurization process, various initial configurations for the adsorption complexes were investigated. Our results suggest that ring hydrogenation does not necessarily lead to a preference for the HYD pathway of thiophene desulfurization. Moreover, surface and electronic effects due to adsorption were also evaluated. We have found that under ideal conditions, vanadium nitride and carbide surfaces present similar activity over desulfurization of thiophene, in qualitative agreement with experiments.