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采用过饱和溶液浸渍法,在不同焙烧温度下制备了LaCoO3/γ-Al2O3煤蚅a0.8Sr0.2CoO3/γ-Al2O3催化剂并对其活性进行测试,利用XRD、BET等技术对样品进行了表征。焙烧温度<600℃,催化剂样品的比表面积相对较大,活性组分在载体Al2O3上分散度高,从而具有较高的活性,并且用Sr部分取代La制得La0.8Sr0.2CoO3/γ-Al2O3催化剂中,Sr的加入有助于钙钛矿的形成,可以促进催化活性的提高;焙烧温度≥600℃,催化剂样品的比表面积呈下降趋势,在载体Al2O3上所负载的LaCoO3或La0.8Sr0.2CoO3由于烧结而长大,造成分散度下降,催化活性变差,掺入Sr未能提高催化剂对甲苯的催化氧化活性,甚至会抑制催化活性。
The LaCoO3 / γ-Al2O3 coal tar a0.8Sr0.2CoO3 / γ-Al2O3 catalyst was prepared by supersaturated solution impregnation method at different calcination temperature, and its activity was tested. The samples were characterized by XRD, BET and other techniques. The calcination temperature is less than 600 ℃, the specific surface area of the catalyst sample is relatively large, and the active component is highly dispersed on the carrier Al2O3, which results in high activity. The La0.8Sr0.2CoO3 / γ-Al2O3 In the catalyst, the addition of Sr is helpful to the formation of perovskite and the promotion of the catalytic activity. The calcination temperature is higher than 600 ℃, the specific surface area of the catalyst sample shows a decreasing trend, and LaCoO3 or La0.8Sr0 supported on the Al2O3 carrier. 2CoO3 grows as a result of sintering, resulting in decreased dispersion and poor catalytic activity. Incorporation of Sr fails to increase the catalyst’s catalytic oxidation activity for toluene, and even inhibits the catalytic activity.