V2O5@CeO2核壳微球结构的脱硝催化剂制备及其抗硫性能

利用静电自组装法制备了V₂O₅@CeO₂核壳微球结构，并负载在TiO₂上。考察了分散剂六偏磷酸钠（SHP（对表面zeta电位的影响，采用扫描电镜（SEM（、投射电镜（TEM（观察了核壳结构的形貌，并在固定床上进行了脱硝性能测试，并通过比表面积（BET（、氨气吸附漫反射（in situ DRIFTS（等进行表征。结果表明：SHP使纳米颗粒表面带负电，且一定范围内SHP浓度越高，zeta电位越大；含质量分数1%V₂O₅、5% CeO₂的催化剂，在260~400℃间具有80%以上的脱硝效率，对比了该核壳结构与传统浸渍法制备催化剂的抗硫抗水性，烟气中含15%（体积分数（H₂O，SO₂含量较低时，脱硝性能优于传统浸渍法制备的催化剂。

Preparation and SO2-resistance of V2O5@CeO2 core-shell microspheres for SCR deNOx

V₂O₅@CeO₂ core-shell microspheres are prepared by electrostatic self-assembly technique and supported on TiO₂. Influences of dispersant (SHP) on zeta potential are investigated. Morphology of obtained microspheres are observed by TEM and FESEM and the catalytic performance for the selective catalytic reduction of NO_x with NH₃ (NH₃-SCR) was investigated in a fixed-bed stainless steel reactor. The catalysts are characterized by BET and in situ DRIFTS analysis of NH₃ adsorption. The results show that the nanoparticle surface is negatively charged by dispersant (SHP) and within a certain range, the higher the concentration of SHP is, the greater the zeta potential are. Catalysts with mass fraction of 1% V₂O₅ and 5% CeO₂ show high activity with the NO_x conversion over 80% from 260 to 400℃. Compared with catalysts prepared by the traditional impregnation method, the core-shell catalysts present higher SO₂ and H₂O resistance at low SO₂ concentration. When the flue gas contains 571 mg·m^-3 SO₂ and 15%(vol) H₂O, the NO_x conversion can be maintained at a high level of 80% after 7 hours.