H_(2)S在B_(16)N_(16)及M@B_(16)N_(16)(M=K,Na,Cl,F)纳米笼催化剂上的分解机理研究  

Decomposition mechanism of H_(2)S on B_(16)N_(16)and M@B_(16)N_(16)(M=K,Na,Cl,F)nanocages

作　　者：李琳 张圳佳 赵蔡斌[1] LI Lin;ZHANG Zhen-jia;ZHAO Cai-bin(School of Chemical and Environment Science,Shaanxi University of Technology,Hanzhong 7230o0,China)

机构地区：[1]陕西理工大学化学与环境科学学院,陕西汉中723000

出　　处：《分子科学学报》2023年第4期369-376,共8页Journal of Molecular Science

基　　金：2021年陕西省大学生创新创业训练计划项目(S202110720050)。

摘　　要：采用密度泛函理论研究了B_(16)N_(16)及M@B_(16)N_(16)(M=K,Na,Cl,F)纳米笼催化剂的稳定性及H_(2)S在催化剂上的分解机理.结果表明,Na和F掺杂有利于提高B_(16)N_(16)稳定性,而K和Cl掺杂则降低了B_(16)N_(16)的稳定性.H_(2)S在催化剂上的降解按H_(2)S→HS+H→S+H_(2)方式进行,第二步为反应的速率控制步.动力学研究表明H_(2)S在B_(16)N_(16)笼上第一步分解的活化能为0.60eV,第二步分解的活化能为2.01eV.Na和K的掺入对H_(2)S降解有利,而F和Cl的掺入则对H_(2)S降解不利.特别是Na@B_(16)N_(16)纳米笼不但展现出良好的稳定性,而且能将速控步能垒从2.01降低至1.23eV左右,应该是H_(2)S降解的优良催化剂.Hydrogen sulfide(H_(2)S)is a toxic gas widely existing in oil/gas exploitation,petrochemical industry,coal chemical industry,and other industries.H_(2)S emission will cause the environmental pollution,the formation of acid rain,and then threaten human health.Numerous studies have proved that H_(2)S can be efficiently decomposed into H_(2) and S by the thermal decomposition technology on the suitable catalyst.However,there are several technical barriers in the process of H_(2)S catalytic decomposition,such as high cost of H_(2) recovery and poor durability of catalyst,which seriously hinder the large-scale application of H_(2)S catalytic decomposition technology.Boron nitride materials can be used as electron transport materials due to their high temperature stability,low dielectric constant,high thermal conductivity,and good oxidation resistance.Recently,researchers found that boron nitride nanocages can provide a high binding energy for hydrogen storage,making them one of the popular hydrogen storage materials.Therefore,we selected B_(16)N_(16)and M@B_(16)N_(16)(M=K,Na,Cl and F)nanocages as possible catalysts in this study,and systematically studied the decomposition process of H_(2)S on these catalysts.Based on density functional theory,the GGA-PBE method was used to calculate the structure and electronic properties of catalyst,and the stability of catalyst and the decomposition mechanism of H_(2)S on them were analyzed.At the same time,the effect of doping atoms on the decomposition of H_(2)S was also studied.The results showed that the incorporation of Na and F can improve the stability of B_(16)N_(16)cage,while the incorporation of K and Cl tends to reduce it.In addition,our results also indicated the degradation of H_(2)S on these catalysts was carried out with the pathway of H_(2)S→HS+H→S+H_(2),and the second step is the rate-determining step.Kinetic study showed that the activation energy of H_(2)S dehydrogenation on the B_(16)N_(16)cage catalyst was only about 0.60 eV,but which was as large as 2.01 e

关 键 词：硫化氢分解 纳米笼催化剂 稳定性 微观机理 

分 类 号：O643[理学—物理化学]