含酮基团对煤焦异相还原NO的影响

基于量子化学密度泛函理论和过渡态理论研究了含酮基团对煤焦异相还原NO的影响及其产物发生氧脱附的微观反应机理。计算结果表明，NO更易于吸附在含酮基团煤焦表面。椅形含酮基团强化了煤焦异相还原NO；锯齿形含酮煤焦表面与NO异相反应决速步能垒值（495.45 kJ/mol）大于锯齿形纯碳基煤焦表面与NO决速步能垒值（331.32 kJ/mol），基于锯齿形含酮煤焦模型中的氧浓度不在利于NO还原的范围内而不易于NO的还原。中间产物P1在无CO存在情况下，较纯碳基煤焦表面更易于发生氧脱附而产生表面缺陷；在CO存在条件下，含酮煤焦表面为氧脱附过程提供自由活性位点，降低了过程能垒消耗。

Effect of ketone group on heterogeneous reduction of NO by char

Based on the density functional theory of quantum chemistry and transition state theory, reaction mechanism of heterogeneous reaction of ketone char with NO and oxygen desorption of the products were examined. The results indicate that NO is more easily adsorbed on surface of the ketone char. The ketone group of armchair enhances the char heterogeneous reduction of NO; On account of oxygen concentration in the ketone of zigzag char may not be within the range where is beneficial to reduction of NO, the energy barrier value of heterogeneous reduction of ketone coal char and NO (495.45kJ/mol) is higher than that of the pure carbon-based char and NO (331.32 kJ/mol). Without the presence of CO, the P1 of intermediate products is more prone to oxygen desorption than the pure carbon-based char, and surface defects are produced. With the presence of CO, the ketone char provides surface free active sites for the oxygen desorption process, which reduces energy barrier of the process.