负载型V_2O_5-WO_3/NiO-TiO_2脱硝催化剂上Ni组分的催化作用

Catalytic effect of Ni component on supported V_2O_5-WO_3/NiO-TiO_2 denitration catalysts

通过共沉淀法将Ni组分掺入到TiO_2载体中,并考察了不同NiO掺杂量对催化剂结构、表面性质与选择性催化还原(SCR)性能的影响。结果表明,NiO掺入到TiO_2中形成NiTiO_3,抑制了TiO_2晶粒的长大。Ni_3V_2O_8中孤立四面体VO_4的存在使催化剂表面Br?nsted酸含量减少,同时NiO_x与VO_x之间的相互作用降低了催化剂的可还原性,Ni_3V_2O_8中V^(4+)的大量存在也不利于催化剂脱硝活性的提高。Ni组分以不当的方式渗入到V_2O_5-WO_3/TiO_2催化剂中对其具有毒化作用。

NiO components were doped to TiO2 carrier of V2O5-WO3/TiO2 catalysts by co-precipitation and the effect of NiO content on the microstructure,surface properties and SCR performance of the catalyst were investigated. Results show that NiO is incorporated into TiO2 to form NiTiO3,which inhibits the growth of TiO2 grains. The presence of isolated tetrahedron VO4 in Ni3V2O8 reduces the Br?nsted acid content on the catalyst surface,while the interaction between NiOx and VOx reduces the reducibility of the catalyst. The existence of V4+ in Ni3V2O8 is also not conducive to the improvement of catalyst denitration activity. Therefore,NiO doping into V2O5-WO3/TiO2 catalysts by an inappropriate method tends to poison the catalysts.