CAJ | 학술논문

采用密度泛函理论（DFT）方法研究了NO和NH3在完整和有缺陷的γ-Al2O3(110)表面吸附与SCR（选择催化还原）反应特性。研究表明，NO在完整的(110)表面的吸附作用较弱，而NH3分子的吸附作用较强，NH3分子在Al原子顶位可形成稳定吸附。反应路径研究结果表明完整的(110)表面上SCR反应的决速步为-NH2NO基团的分解，反应的最大能垒为235.75 kJ·mol-1。对于产生氧空穴的有缺陷(110)表面，NO和NH3均可稳定吸附， NH3在吸附过程中可直接裂解成NH2和H。另外，SCR反应在有缺陷(110)表面的最大能垒明显较低，说明氧空穴的存在促进了SCR脱硝反应的进行。
채용밀도범함이론（DFT）방법연구료NO화NH3재완정화유결함적γ-Al2O3(110)표면흡부여SCR（선택최화환원）반응특성。연구표명，NO재완정적(110)표면적흡부작용교약，이NH3분자적흡부작용교강，NH3분자재Al원자정위가형성은정흡부。반응로경연구결과표명완정적(110)표면상SCR반응적결속보위-NH2NO기단적분해，반응적최대능루위235.75 kJ·mol-1。대우산생양공혈적유결함(110)표면，NO화NH3균가은정흡부， NH3재흡부과정중가직접렬해성NH2화H。령외，SCR반응재유결함(110)표면적최대능루명현교저，설명양공혈적존재촉진료SCR탈초반응적진행。
γ-Al2O3is an outstanding catalyst carrier and has been widely used in the SCR (selective catalytic reduction) catalyst study. The adsorption and reaction properties of NO/NH3 on the bare and defectiveγ-Al2O3 (110) surface were studied by the DFT (density functional theory) method. The corresponding microscopic parameters, such as adsorption energies, bond length, changes of net charge and PDOS (partial density of states) were calculated. NO could be adsorbed on the bare (110) surface weakly, and it was more inclined to be adsorbed on the top sites of O2c. NH3 could be adsorbed strongly on top sites of Al. The rate-determining step of SCR reaction was the-NH2NO decomposition, while the largest energy barrier reached 235.75 kJ·mol-1. For the defective (110) surface with the oxygen vacancy, NO and NH3 could be both adsorbed strongly on the surface, and NH3 could also decompose into NH2 and H directly in this situation. The largest energy barrier of SCR reaction in this situation was much lower, indicating that the presence of oxygen vacancy could promote SCR reaction proceeding.