烟气脱汞过程中Ce掺杂对于不同吸附质在MnO2（110）表面吸附机理的研究

Study on the adsorption mechanism of different adsorbents on the surface of MnO2 (110) by Ce doping in the process of flue gas mercury removal

摘要:

基于密度泛函理论（DFT）的第一性原理，采用Materials Studio软件计算模拟研究了烟气催化脱汞过程中Hg0，Cl和HgCl在Ce掺杂前后MnO2（110）表面的吸附状态．结果表明：在Ce掺杂前后，Hg0和Cl都是优先吸附在MnO2（110）表面的含氧位点，且从掺杂后形成的键长更大，表明掺杂有利于反应体系活性的增加；HgCl吸附时，Ce掺杂前后不管是以Hg端吸附还是以Cl端吸附都是化学吸附，且以Hg端吸附在O位点上较为稳定，以Hg端吸附时HgCl的键能大于新形成的键能，有利于HgCl作为整体进一步与Cl反应生成最终的产物HgCl2．

Abstract:

Based on the first principles of density functional theory (DFT), Materials Studio software was used to calculate and simulate the adsorption state of Hg0, Cl and HgCl on the MnO2(110) surface before and after Ce-doping in the process of flue gas catalytic mercury removal. The results show that both Hg0 and Cl are preferentially adsorbed on the surface of oxygen-containing sites towards MnO2 (110) before and after towards．The bond length formed after doping is larger，indicating that doping is beneficial to the increase of the activity of the reaction system. When HgCl is adsorbed, both before and after the Ce-doping, whether it is adsorbed at the Hg end or at the Cl end．It is chemical adsorption, and the Hg end is adsorbed on the O site more stable．Moreover, when the Hg end adsorption occurs，the bond energy of HgCl is greater than the newly formed bond energy, which is conducive to the further reaction of HgCl as a whole with Cl to generate the final product HgCl2．