CeO₂in different morphologies with 2, 4-dihydroxybenzonic acid as auxiliary: Synthesis and application in NH₃-SCR

Different morphologies (rod-like and sheet-like) of CeOHCO₃were controllably synthesized by using 2, 4-dihydroxybenzonic acid (DHBA) as auxiliary. During the hydrothermal process, the morphologies of CeOHCO₃were controlled by adding different amount of DHBA. When the amount of DHBA was 3.5 mmol, rod-like CeOHCO₃was synthesized, while by increasing the amount of DHBA to 5.0 mmol, the sheet-like CeOHCO₃was relatively generated. Then the rod-like and sheet-like fcc-CeO₂(face-centered cubic-CeO₂) were successfully obtained by the subsequent calcination procedure. The resulted CeO₂affords large surface area (> 60 m2·g^-1), while the rod-like CeO₂exhibits higher redox ability and more acid amount compared to those of sheet-like CeO₂. In addition, the rod-like CeO₂exhibits better catalytic activity in NH₃-SCR.