【摘要】 以钒磷氧化物（VPO）为活性组分，TiO₂为载体，通过改变制备条件，制备具有不同表面酸性位特性的钒磷氧催化剂VPO/TiO₂,并对其低温脱硝活性和表面酸性进行了研究。结果表明，当HCl/V摩尔比为3、V/P摩尔比为5、VPO煅烧温度为450℃时，制得的VPO/TiO₂催化剂表现出优异的脱硝活性，200℃时脱硝效率接近100%。VPO/TiO₂催化剂主要活性晶相为（VO）₂P₂O₇、V₂O₅和VOPO₄。催化剂表面具有大量的酸性位点，通过数据拟合建立了脱硝活性与表面酸量间的相关性，结果表明所有VPO/TiO₂催化剂的低温脱硝活性均与弱Lewis酸含量呈正相关（相关系数>0.9）。此外，对脱硝机理进行研究表明，NH₃以配位态NH₃或NH⁺₄吸附于VPO/TiO₂表面，并参与后续选择性催化还原（SCR）反应，反应过程中NO被氧化成NO₂或单齿硝酸盐后最终被还原。在VPO/TiO₂催化剂的SCR反应过程中Eley-Rideal机理和Langmuir-Hinshelwood机理并存。更多还原

【Abstract】 Vanadium phosphorus oxygen catalysts VPO/TiO₂ with different surface acidity characteristics were prepared using vanadium phosphorus oxygen（VPO） as active component and TiO₂ as support by changing the preparation conditions. Their low temperature denitrification activities and surface acidity were studied. The results showed that when HCl/V molar ratio was 3,V/P molar ratio was 5 and the calcination temperature of VPO was 450 ℃,the obtained VPO/TiO₂ catalyst exhibited excellent denitration activity, with nearly 100% denitration rate at 200 ℃. The main active crystal phases of VPO/TiO₂ catalysts were（VO）₂P₂O₇,V₂O₅ and VOPO₄. VPO/TiO₂ surface had a large number of acidic sites, and the correlation between the denitrification activity and the amount of acid on the catalyst surface was established by data fitting, which showed that the low-temperature denitrification activities of all VPO/TiO₂ catalysts were positively correlated with the weak Lewis acid content（correlation coefficient>0.9）. In addition, the denitrification mechanism studies revealed that the NH₃ adsorbed on VPO/TiO₂ surface in state of coordination NH₃ or NH⁺₄,and participate in the further selective catalytic reduction reaction. The NO was oxidized to NO₂,monodentate nitrate before eventually reduced. SCR reaction over VPO/TiO₂ followed the Eley-Rideal and Langmuir-Hinshelwood mechanism simutanously.更多还原