A series of silicotungstic acid modified CeO₂ (SC-x, x represents the pH value of solution that is used for the preparation of catalysts) were prepared for the selective catalytic reduction (SCR) of NO_x with NH₃. SC-9 showed the best catalytic activity among the samples. The monodentate nitrate, bidentate nitrate, bridging nitrate and NO₂ were detected over SC-9 and SC-10. Monodentate nitrate and bridging nitrate disappeared over SC-8. Furthermore, the monodentate nitrate and bridging nitrate could react with NH₄⁺ on Brønsted acid sites to generate NH₄NO₃, and then was reduced by NO to form NO₂, accompanied with the fast reaction between NO₂ and coordinated NH₃ on Lewis acid sites in the presence of gaseous NO. Besides, the SCR reaction pathway of SC catalysts followed by the Langmuir–Hinshelwood mechanism and the Eley–Rideal mechanism.

改性的CeO一系列硅钨酸₂（SC- X，X代表一个用于催化剂的制备溶液pH值）中用于选择性催化还原（SCR）中制备的NO _X与NH ₃。SC-9在样品中显示出最佳的催化活性。在SC-9和SC-10上检测到了单齿硝酸盐，双齿硝酸盐，桥连硝酸盐和NO ₂。单齿硝酸盐和桥连硝酸盐在SC-8上消失了。此外，单齿硝酸盐和桥连硝酸盐可与布朗斯台德酸位上的NH ₄ ⁺反应生成NH ₄ NO ₃，然后被NO还原形成NO _2。，伴随着气态NO存在下NO ₂与配位NH ₃在路易斯酸位上的快速反应。此外，SC催化剂的SCR反应路径依次为Langmuir-Hinshelwood机理和Eley-Rideal机理。