铜改性凹凸棒土催化剂对Hg0及NH3的氧化性能研究

采用改进湿式浸渍法制备了兼备汞氧化和氨氧化活性的铜改性凹凸棒土（Cu₃-ATP）催化剂，对其进行SEM、H₂-TPR和NH₃-TPD表征，并在150-400℃测试其汞氧化及氨氧化性能。结果表明，铜物种成功负载在ATP表面，显著提高了催化剂的氧化还原能力，增加了表面中强酸性位和部分强酸性位，从而有效促进Hg⁰和NH₃的氧化。HCl在Hg⁰的高效氧化中起重要作用，高温不利于Hg⁰氧化反应的进行，但能够促进NH₃的氧化。在350℃下，Cu₃-ATP对Hg⁰和NH₃的氧化效率均在90%以上。影响因素实验显示，高空速下NH₃对汞氧化反应有明显抑制作用，而低浓度Hg⁰及HCl对氨氧化活性无显著影响，当气体空速（GHSV）低于5×10⁴ h^-1时，Cu₃-ATP能够实现NH₃和Hg⁰的同时氧化。此外，汞的氧化反应具备良好的抗硫性和抗水性，而SO₂对氨氧化有一定抑制作用。

Study on the Hg0 and NH3 oxidation performance of copper modified attapulgite catalysts

A copper-modified attapulgite (Cu₃-ATP) catalyst with both mercury oxidation and ammonia oxidation activities was prepared by an improved wet impregnation method. Several characterization including SEM, H₂-TPR and NH₃-TPD were performed on it, and its mercury oxidation and ammonia oxidation performance were tested at 150-400 ℃. The results show that the copper species is successfully loaded on ATP surface, which significantly improves the redox ability of the catalyst, increases the strong acid sites and partial strong acid sites on the surface, and thus promotes the oxidation of Hg⁰ and NH₃. HCl plays an important role in Hg⁰ oxidation. High temperature is not conducive to the Hg⁰ oxidation reaction, but can promote the oxidation of NH₃. At 350 ℃, the oxidation efficiencies of Hg⁰ and NH₃ over Cu₃-ATP are both above 90%. Experiments on the influencing factors show that NH₃ has an obvious inhibitory effect on mercury oxidation at high space velocity, while low concentrations of Hg⁰ and HCl have no significant influence on ammonia oxidation. When the gas hourly space velocity (GHSV) is lower than 5×10⁴ h^-1, Cu₃-ATP can simultaneously oxidize NH₃ and Hg⁰. In addition, the mercury oxidation reaction shows good sulfur resistance and water resistance, but SO₂ has a certain inhibitory effect on ammonia oxidation.