纳米CeO2基固溶体催化柴油机碳颗粒物燃烧性能

采用柠檬酸溶胶鄄凝胶法制备CeO2基固溶体催化剂(Ce0.7Zr0.3O2-δ、Ce0.7Pr0.3O2-δ和Ce0.7Gd0.3O2-δ), 并考察了固溶体和三种常用载体(TiO2、SiO2和Al2O3)及其负载KNO3后的催化碳黑燃烧活性. 结果表明, CeO2基固溶体催化剂具有很高的催化燃烧活性, 其活性接近TiO2、SiO2和Al2O3负载30%KNO3催化剂的活性. 因为纳米CeO2基固溶体的形成, 提高了催化剂的抗烧结能力, 使氧更活泼, 从而提高氧化还原性能, 有利于碳颗粒燃烧. 由于CeO2基固溶体本身的高活性, 因此KNO3的添加不能明显提高CeO2基固溶体催化剂(尤其是Ce0.7Zr0.3O2-δ和Ce0.7Pr0.3O2-δ)的催化燃烧活性, 但KNO3能显著提高TiO2, SiO2和Al2O3的催化燃烧活性.

Catalytic Combustion of Diesel Soot on Nanocrystalline CeO2-based Solid Solutions

CeO2-based solid solutions (Ce0.7Zr0.3O2-δ, Ce0.7Pr0.3O2-δ, and Ce0.7Gd0.3O2-δ) were prepared using a sol-gel method. Catalytic behaviors for diesel soot combustion over the CeO2-based solid solutions and three typical supports (TiO2, SiO2, and Al2O3) and their KNO3 doped catalysts have been studied. It was found that the CeO2-based solid solution catalysts had nearly the same good catalytic activity as the 30% KNO3 doped TiO2, SiO2, and Al2O3 had. As the formation of the CeO2-based solid solutions can slow down the sintering process and form more active oxygen, which enhanced the reducibility and hence improved the catalytic combustion activity. As the intrinsic high activity of the CeO2-based solid solutions, the addition of the KNO3 did not have obvious effect on them, especially for Ce0.7Zr0.3O2-δ and Ce0.7Pr0.3O2-δ, while for TiO2, SiO2, and Al2O3, the addition of KNO3 could remarkably enhance the combustion activity.