等离子体引发CeO_2低温活性协同脱除空气中甲醛

Synergistic removal of formaldehyde from air thanks to plasma-initiated catalytic activity of CeO_2 at low temperature

为考察放电电压、甲醛初始体积分数和水体积分数对空气中甲醛脱除率的影响,选取催化剂MnO2、CeO2、TiO2分别与等离子体结合,在标准大气压、40℃条件下进行脱除甲醛实验。结果表明:空气中甲醛的体积分数为2.01×10-4、水的体积分数为1.0%、空速为13 650 h-1、放电电压为18 kV时,CeO2与等离子体结合的甲醛脱除率达98.5%;在相同条件下,单纯等离子体和单纯CeO2催化氧化(不放电)对甲醛的脱除率分别为62.5%和8.0%。等离子体与催化剂在脱除空气中甲醛的过程中产生了显著的协同作用。该研究为脱除空气中甲醛提供了理论参考。

This paper highlights a new combination which combines CeO2, MnO2 and TiO2 catalysts respectively with the plasma as a way to eliminate formaldehyde in air at atmospheric pressure and temperature 40℃. The combination works better for investigating the effects of discharge voltage, initial formaldehyde concentration and water concentration on formaldehyde removal rate. This investigation sug- gests that with the presence of the formaldehyde volume fraction of 2.01×10 -4, the water volume fraction of 1%, the airspeed of 13 650 h-1, and the input discharge voltage of 18 kV, the combination of the dielectric barrier discharge plasma with CeO2, enables a formaldehyde removal rate up to 98.5%, compared to 62.5% and 8.0% respectively for pure plasma-induced oxidation and pure catalytic oxidation CeO2 （without discharges）. It follows that the combination of plasma and CeO2 catalyst produces a signifi- cant synergistic effect on the removal of formaldehyde in the air. The investigation may provide a theoreti- cal reference for the removal of formaldehyde in air.