Cu(x)/TiO2催化剂NH3-SCR低温脱硝性能

Denitrification performance of Cu(x)/TiO2 catalysts for selective catalytic reduction of NO with NH3 at low temperature

摘要:

以硝酸铜和二氧化钛为原料，采用浸渍法制备Cu(x)/TiO2（x=1, 3, 4, 5, 6, 7；x为以TiO2载体质量为基准的铜负载量，质量百分数/%，下同）催化剂。运用XRD、XPS、NO-TPD、H2-TPR等对催化剂进行了表征，在微型固定床反应器中评价了Cu(x)/TiO2催化剂在以NH3为还原剂的选择性催化还原NO反应（NH3-SCR）脱硝活性。结果表明，铜物种以Cu2O和CuO的形式共存于TiO2载体上。铜负载量影响催化剂的脱硝性能。Cu(6)/TiO2催化剂表现出较好的氧化还原性和对反应物NO的吸附-脱附能力，低温（<300 ℃）脱硝活性较好，NO转化率达到85%和95%时对应反应温度T85和T95分别为195 ℃和218 ℃，NO转化率大于95%的活性窗口温度为218~270 ℃，宽度为52 ℃。

Abstract:

Cu(x)/TiO2 (x=1, 3, 4, 5, 6, 7; x is the amount of copper loading based on the mass of TiO2 carrier, mass percent/%, the same below) catalysts were prepared by impregnation method using copper nitrate and TiO2 as raw materials. The catalysts were characterized by XRD, XPS, NO-TPD and H2-TPR. The performance of the catalysts for the selective catalytic reduction of NO with NH3 (NH3-SCR) was evaluated in a fixed-bed micro-reactor. The results showed that copper species existed in the form of Cu2O and CuO on the TiO2 carrier. The denitrification performance of catalysts was affected by the amount of copper loading. The Cu(6)/TiO2 catalyst exhibited excellent redox properties and good adsorption/desorption performance for reactants, which showed a good catalytic activity in denitrification reaction even at low-temperature (<300 ℃). When the conversion of NO reached 85% and 95%, the reaction temperature T85 and T95 were 195 ℃ and 218 ℃, respectively. The temperature range for the NO conversion over 95% was from 218 ℃ to 270 ℃ with a width of 52 ℃.