蜂窝状微量贵金属催化剂对几种典型VOCs的催化氧化性能

Performance of honeycomb catalyst containing micro-noble mental on catalytic oxidation of several typical VOCs

研制出了用于催化氧化废气中挥发性有机化合物(VOCs)的蜂窝状微量贵金属催化剂。用浸渍法制备催化剂Pt-Ce-La-Zr/Al2O3,并在自行设计的活性检测系统上,对用该催化剂净化含有苯、甲苯、乙醇、正己烷的模拟废气进行了研究,考察了空速、质量浓度等因素对催化剂活性的影响。实验结果表明,该催化剂对上述几种典型的VOCs气体都具有较低的起燃温度,其催化转化活性较好。

The paper is concerned about a honeycomb catalyst, known as the Pt-Ce-La-Zr/Al2O3 catalyst, developed by the present authors based on the micro-noble metals for catalytical oxidation of volatile organic compounds （VOCs） in a waste gas. The catalyst under development has been prepared through impregnation, and then checked on a system designed by us authors. A simulated investigation has also been done with the catalyst to determine the effects of the space welocity and reactant concentration on the catalyst when it works with the gas with benzene, toluene, ethanol or n-hexane in the aetivation-cbecking system. The results of our experiments indicate that the catalyst enjoys a nice adaptability to the changes of the experimental conditions, such as space velocity, reactant concentration or the kind of VOCs, which prove to have little or no effect on the activities of the catalyst. Therefore, the catalyst of ours proves to be highly flexible to its working conditions. In addition, the testing resuits also indicate that the catalyst has low light-giving-off temperatures and perfect conversion efficiency with a few kinds of typical VOCs. For example, under the effect of the said catalyst, the lightgiving off temperatures prove to be 185 ℃, 190 ℃, 150 ℃ , respectively. And full combustion temperatures of benzene, toluene, ethanol separately turn to be 190 ℃, 220 ℃, 195 ℃ , respectively, under the experimental conditions of 13 000 h^-1. Besides, with the, catalyst hereby discussed, the mass proportion of chloroplatinic acid in its raw material is only about 0,05 % and the mass proportion of assistants （assistants containing cerous nitrate, lanthanum nitrate and zirconium nitrate） is only 0.5 % that helps to ensure desirable oxidation activity and rather low cost. In conclusion, it can be said that the present catalyst can display quite satisfactory utilization properties and thus enjoys practical industrial application prospects.