摘要
通过第一性原理计算研究了Ti_(2)NO_(2) MXene对H_(2)S的吸附、分解行为. Ti_(2)NO_(2)对H_(2)S气体分子的吸附结果表明,两者之间为弱的物理吸附, Ti_(2)NO_(2)无法有效吸附H_(2)S气体.采用过渡金属(Sc、 V)修饰Ti_(2)NO_(2)的研究结果表明,Sc和V可以在Ti_(2)NO_(2)表面上稳定存在,不易发生团聚,其最稳定吸附位为N原子上方.进一步研究了Sc、 V修饰的Ti_(2)NO_(2)对H_(2)S气体分子的吸附行为,结果表明金属修饰后其吸附H_(2)S的能力明显提高.此外还发现, H_(2)S分子可以在Sc/Ti_(2)NO_(2)和V/Ti_(2)NO_(2)表面直接解离为HS^(*)和H^(*),而后HS^(*)中的H原子再与H^(*)进一步结合形成H_(2), S原子则与过渡金属成键. HS^(*)在V/Ti_(2)NO_(2)表面解离的势垒为1.69 eV,低于在Sc/Ti_(2)NO_(2)表面的2.08 eV,表明V/Ti_(2)NO_(2)有望成为吸附、分解H_(2)S气体的理想候选材料.
First-principles calculations are used to study the adsorption and decomposition behavior of H_(2)S on Ti_(2)NO_(2) MXene. The adsorption results of H_(2)S gas molecules on Ti_(2)NO_(2) show that the adsorption belongs to weak physical adsorption, and the H_(2)S gas can not be adsorbed effectively by Ti_(2)NO_(2). The results of the modification of Ti_(2)NO_(2) by transition metals(Sc, V) show that Sc and V can stably anchor on the surface of Ti_(2)NO_(2) and are not easy to agglomerate, and the most stable adsorption site is the top of N atom. The adsorption behavior of H_(2)S gas molecules on Sc and V modified Ti_(2)NO_(2) arefurther studied. The results show that the adsorption strength of H_(2)S was significantly improved on the transition-metal modified Ti_(2)NO_(2). In addition, H_(2)S molecules can be directly dissociated into HS^(*) and H^(*) on the surface of Sc/Ti_(2)NO_(2) and V/Ti_(2)NO_(2), and then the H atom in HS^(*) combines with H^(*) to form H_(2), and the S atom bonds with the transition metal. The dissociation barrier of HS^(*) on the surface of V/Ti_(2)NO_(2) is 1.69 eV, which is lower than the 2.08 eV on the surface of Sc/Ti_(2)NO_(2), indicating that V/Ti_(2)NO_(2) is expected to be an ideal candidate material for H_(2)S gas adsorption and decomposition.
作者
于书敏
王岚
齐礼磊
邢盈盈
张淑洁
吕晓静
李晓璐
王军凯
YU Shu-min;WANG Lan;QI Li-lei;XING Ying-ying;ZHANG Shu-jie;LU Xiao-jing;LI Xiao-lu;WANG Jun-kai(Henan Key Laboratory of Materials on Deep-Earth Engineering,School of Materials Science and Engineering,Henan Polytechnic University,Jiaozuo 454003,China)
出处
《分子催化》
CAS
CSCD
北大核心
2021年第4期343-352,I0002,共11页
Journal of Molecular Catalysis(China)
基金
河南省科技攻关计划(212102210589)
河南理工大学博士基金(B2019-40)。
