Synthesis of high performance diesel oxidation catalyst using novel mesoporous AlLaZrTiOx mixed oxides by a modified sol-gel method

High performance diesel oxidation catalyst (DOC) is achieved using novel Al2O3-LaAlO3-ZrO2-TiO2 (AlLaZrTiOx) mixed oxides and has been successfully fabricated by a modified sol-gel method. It is worth noting that novel AlLaZrTiOx mixed oxides own outstanding properties, such as mesoporous structure, high specific surface area, and thermal stability, which are confirmed by N-2 adsorption-desorption, TEM, small-angle x-ray diffraction, and XRD spectrum. For these mixed oxides, temperature has a significant effect on their properties, for example, high specific surface area (206.5 m(2)/g) with a pore volume of 0.5 cc/g can be obtained by calcining at 700 degrees C for 4 h. Meanwhile, the possible synthesis mechanism of mesoporous AlLaZrTiOx mixed oxides was also discussed. Finally, the catalytic performances of Pt-Pd/AlLaZrTiOx catalyst and commercial catalyst were compared under the same simulated clean diesel combustion. Pt-Pd/AlLaZrTiOx catalyst demonstrated an excellent low temperature oxidation catalytic activity with the conversion of CO and total hydrocarbon (C3H6) reaching 90% at 196 degrees C and 200 degrees C, respectively. Specially, the conversion of NO reached 75% when the temperature was at around 200 degrees C.