以光觸媒/沸石複合材料同時處理VOCs及NOx之研究

Abstract

傳統吸附劑除污能力受到吸附容量的影響，飽和後需做再生或更換才能維持原處理功效，使其使用受到限制。本研究目的係以沸石結合光觸媒合成之複合材料，在常溫並輔以紫外光的照射下，將空氣中的NO與VOCs氣狀污染物質同時去除，達到先將污染物吸附於吸附材上，再進行光催化分解之效果，不僅可以同時處理兩種污染物質，還能改善傳統吸附劑只能吸附而無法去除之缺憾。實驗所製備之光觸媒/沸石複合材料，乃經由XRD、SEM、UV-Vis、BET等表面分析儀器進行表面特性分析。實驗的進行是以連續式反應器，在365 nm紫外光波長照射下，以兩種不同流量，分別針對不同合成比例之光觸媒/沸石複合材料作測試。實驗結果證實複合材料可有效提升單獨沸石或單獨光觸媒之同時去除NO與丙酮效能，並發現在本實驗條件下，光觸媒/沸石的重量合成比例為40%與60%時擁有最佳的NO除污效能，80%比例則有最佳丙酮除污效能。而針對60%的光觸媒/沸石重量合成比例，探討單獨與同時去除NO與丙酮之研究，發現複合材料於同時去除NO與丙酮，可增進NO去除效果，且不影響丙酮去除效率。而對單純光觸媒樣品而言，兩者則互為競爭去除，同時處理的效率會低於單獨處理之效率。

Due to the limited adsorption capacity of traditional adsorbent, it is necessary to regenerate or replace the adsorbent for ensuring high pollutant removal efficiency. The purpose of this research is to combine photocatalyst and zeolite as a composite catalytic adsorbent to continuously and simultaneously remove NO and VOCs under UV illumination at room temperature. It achieves the goal that photocatalyst/zeolite composite can adsorb the pollutants onto the material, then the photocatalytic decomposition is being processed and the pollutants are destructed. As a result, the lifetime of traditional adsorbent is increased. The catalysts are characterized by XRD、SEM、UV-Vis、BET and FT-IR analyzer. Pollutant abatement tests are carried out by a continuous flow reactor under 365nm UV illumination. Results show that photocatalyst/zeolite composite is more effective to removal NO and acetone than the pure zeolite or pure photocatalyst. For simultaneous removal of NO and acetone, the 40/60 and 60/40 mass ratio of photocatalyst/zeolite composites show the highest NO removal, and the 80/20 sample is the best for acetone removal. For the test of 60/40 sample, it is found that the coexistence of NO and acetone enhances NO removal efficiency without influencing the acetone removal. But for pure photocatalyst, the coexistence of NO and VOCs results in decreases of NO and VOCs removal efficiencies.