中文摘要：

以非均相沉淀法制备了凹凸棒石（PG）载体上负载锰氧化物催化剂Mn/PG,并用于低温选择性催化还原法（SCR）脱硝反应.采用X射线衍射、透射电子显微镜和H2-程序升温还原方法对催化剂进行了表征;通过NH3吸脱附实验考察了催化剂的锰负载量和煅烧温度对NH3吸附和脱附量及吸附位的影响.结果表明,锰氧化物高度分散于PG晶体表面,其存在状态取决于催化剂煅烧温度.煅烧温度低于550℃,锰氧化物为Mn2O3和Mn3O4,煅烧温度为550℃时,锰氧化物为Mn3O4.NH3主要吸附在PG载体上,锰氧化物的担载基本不影响催化剂吸附NH3的能力,但促进了吸附NH3的活化,这是催化剂SCR活性显著增加的直接原因.

英文摘要：

A Mn/palygorskite catalyst for low-temperature selective catalytic reduction （SCR） of NO by NH3 was prepared by heterogeneous co-precipitation followed by drying and calcination. NH3 adsorption capacity of the catalyst, which is generally considered to be a key property of SCR catalysts, was investigated by experiments of ammonia adsorption and temperature-programmed desorption （TPD）. Physico-chemical properties of the catalyst were characterized by X-ray diffraction, transmission electron microscopy, temperature-programmed reduction in H2. The results showed that manganese oxides are highly dispersed on the surface of the palygorskite support. The surface manganese species exist as Mn2O3 and Mn3O4 at calcination temperature lower than 550 ℃ and as Mn3O4 at 550 ℃. Adsorption of ammonia on the catalyst occurs mainly on the palygorskite support. The manganese oxide loading does not promote the NH3 adsorption on the catalyst but increases the activation of the adsorbed NH3. This is the main reason for the remarkable increase in catalytic activity of the palygorskite-based catalyst.