K2Ti2O5的制备及其对柴油机尾气碳黑催化氧化的性能

Preparation and catalytic performance of potassium titanates used as soot oxidation catalyst in diesel exhaust

以醋酸钾(CH3COOK)、钛酸四丁酯(Ti(OC4H9)4)、无水乙醇和柠檬酸等为原料,采用柠檬酸配位燃烧法合成钛酸钾系列碳黑氧化催化剂(DOC)K2Ti2O5。利用X线衍射仪(XRD)、场发射扫描电子显微镜(FESEM)、透射电子显微镜(TEM)表征K2Ti2O5的晶相及表面形貌;利用程序升温反应(TPR)考察老化时间、K2Ti2O5与碳黑颗粒的接触方式、焙烧温度、尾气中SO2和水蒸气含量、重复使用等因素对K2Ti2O5催化活性的影响。结果表明:K2Ti2O5催化活性较高,起燃温度低至280℃,峰值温度为322℃,催化活性在同类活性金属钛氧化物中最好,并且具有良好的重复使用稳定性及抗SO2和水蒸气稳定性。

Potassium titanate catalyst K2Ti2O5 was prepared by citrate acid complex-combustion using CH3 COOK, Ti （OC4H9 ）4, anhydrous ethanol, and citrate acid as raw materials. The crystalline phase, surface area and surface morphology of K2Ti2O5 were investigated by X-ray diffraction（XRD） ,field emission scanning electron microscope （ FESEM ）, and transmission electron microscope （ TEM ）. Some influence factors, such as the contact type between K2Ti2O5 and soot, the content of water vapor and SO2 in exhaust, and the reuse of the catalyst, were studied by temperature programmed reaction （TPR）. The results showed that K2Ti2O5 had high catalytic activity, with the ignition temperature being as low as 280 ℃, the peak temperature being 322 ℃, and good renewable capacity and stability.