Catalysis Today, Vol.320, 133-140, 2019
Improvement of thermal stability of microporous TiO2 for NH3-SCR reaction using multivalent cations
The thermal stability of polycrystalline microporous TiO2 (m-TiO2) has been improved by incorporating multivalent cations such as La3+ and Ce3+. The changes in the crystal structure upon heating were monitored using X-ray powder diffraction and N-2 adsorption-desorption isotherms. The presence of multivalent cations significantly increased the thermal stability of TiO2, as inferred from the changes in the surface area, pore volume, and X-ray diffraction pattern. The catalytic performance of the pristine V/m-TiO2 catalyst in the NH3-SCR reaction increased from 40% to 70% and 80% by using the V/m-TiO2 catalyst containing La3+ and Ce3+, respectively, after thermal treatment at 500 degrees C for 2 h. Further it was demonstrated that the addition of WOx onto La3+ or Ce3+ modified m-TiO2 affected the corresponding thermal stability and the catalytic performance, suggesting that the Ce3+ seemed to be best for the improvement of thermal stability.