SCR催化剂表面TiO_(2)复合涂层的抗碱金属性能研究

Research on Alkali Metal Resistance of SCR Catalyst by Surface Coating of TiO_(2) Composite

本文通过在催化剂表面涂敷纳米TiO_(2)复合涂层的方式来阻隔碱金属K与催化剂上酸性位点的结合,从而提升催化剂的抗碱金属性能。采用SEM-EDS、ICP-OES、H_(2)-TPR及NH_(3)-TPD表征手段对涂层处理后样品的抗K性能进行评价。结果表明,涂层处理后样品中沉积的K元素较处理前降低了75%,且KCl中毒处理后脱硝活性仍可达60%~80%;涂层中MgO的添加可进一步提升其在高温下的抗K性能,但会损失10%~15%的初始活性;催化剂的抗水抗硫性能不受涂层的影响。

The alkali metal resistance of the V_(2)O_(5)-WO_(3)/TiO_(2)catalyst was improved by coating nano-TiOcomposite washcoat on the surface of the catalyst to block the combination of K element with acid sites. The K resistance of the treated samples was characterized by SEM-EDS, ICP-OES,H_(2)-TPR and NH_(3)-TPD. The results showed that the coated sample is significantly more active than the initial sample after K doping. The NO conversion of the KCl doped coated sample can still maintain at 60%~80%. The addition of MgO in the coating could further improve the K resistance of the catalyst, but its initial activity would decrease by 10% to 15%. Besides, the water and sulfur resistance of the catalyst did not decline due to TiOsurface coating.