B掺杂C3N对SO2催化氧化的第一性原理研究

First Principle Study of Catalytic Oxidation of SO2 by B-doped C3N

通过第一性原理计算,采用Dmol3模块考察了B原子分别掺杂C3N二维材料的C位(B/C-C3N)和N位(B/N-C3N)所形成的两种单原子催化剂的结构、电子性质以及催化性能。首先,分析了B掺杂C3N的两种结构的稳定性与电子性质,发现B的掺杂使两种结构的稳定性均显著增强,B/C-C3N的电子性质变化更大,由半导体变成了导体。然后,分析了C3N、B/C-C3 N和B/N-C3 N这3种催化剂对SO 2氧化反应的催化性能,计算比较了对O2与SO2的吸附能、电荷转移量、稳定构型、态密度以及O 2活化后的键长。结果显示3种催化剂对O 2的吸附能均大于SO2,均服从E-R机理,其中B/C-C3N对O2的吸附能最大、O2与SO2之间吸附能之差最大,对O2的活化程度最高,表现出最利于SO2催化氧化反应的性能。态密度分析也表明,O2与B/C-C3N在费米能级附近的杂化作用最强,这更利于反应的发生。因此,B/C-C3N具有成为SO2氧化反应优良催化剂的潜力。

Based on the first principle calculation,the structures,electronic properties and catalytic performances of two kinds of monoatomic catalysts,which are formed by the doping of B atom into C-position(B/C-C3N)and N-position(B/N-C3N)of C3N two-dimensional materials,are investigated by the Dmol3 module.Firstly,the stability and electronic properties of the two structures with B-doped C3N are analyzed.It is found that the stability of the two structures is significantly enhanced by the doping,and the electronic properties of B/C-C3N changed significantly,from semiconductor to conductor.Then,the catalytic performance of C3N,B/C-C3N and B/N-C 3N catalysts for SO2 oxidation is analyzed respectively.The adsorption energy,charge transfer,stable configuration,density of states and bond length of activated O 2 are calculated and compared.The results show that the adsorption energy of the three catalysts for O2 is higher than that of SO2,and all of them follow E-R mechanism.The adsorption energy of B/C-C3N for O2 is the largest,and the adsorption energy difference between O2 and SO2 is the largest.The results of density of state analysis show that the hybridization between O2 and B/C-C3N is the strongest near Fermi level,which is more conducive to the occurrence of the reaction.Therefore,B/C-C3N has the potential to be an excellent catalyst for SO2 oxidation.