CO对碳基吸附汞的影响机理研究

Effect of Carbon Monoxide on Mercury Adsorption on Carbonaceous Materials

应用密度泛函理论B3PW91方法计算CO在碳基表面的吸附结构和吸附能,并研究了CO对碳基吸附汞的影响机理。建立了含有CO的碳基固体表面簇模型,计算结果表明CO在碳基表面有三种稳定的吸附模式,主要以C端垂直吸附和平行吸附为主,吸附能在-173.8 kJ/mol到-304.7 kJ/mol之间,属于较强的化学吸附。汞在含有CO的碳基表面的吸附能在-87.7 kJ/mol到-109.4 kJ/mol之间,大于汞在不含CO的碳基表面的吸附能。CO对单质汞在碳基表面吸附的影响机理比较复杂,与烟气中CO的含量有关。

The density functional theory B3PW91 was performed to investigate the effect of CO on mercury adsorption on a carbonaceous surface. The possible cluster models in which CO adsorbed on the carbonaceous surface were considered and the adsorption energies were calculated. There are three stable models when CO adsorbs on carbonaceous surface. The adsorption energies of CO adsorptions with side-on and C-down modes are between chemisorptions. The adsorption energies of Hg -173.8 kJ/mol and -304.7 k J/mol, which belong to on carbonaceous surface with CO are between -87.7 kJ/mol and -109.4 k J/mol, which are larger than that of Hg on carbonaceous surface without CO. The results indicate that the effect of CO on Hg adsorption on carbonaceous surface is complicated and depends on the concentration of CO in the flue gas.