Ce_(x)Zr_(1-x)O_(y)常温催化氧化去除甲醛的研究

Study on catalytic oxidation of formaldehyde over CexZr1-xOy catalyst at room temperature

室内甲醛对环境和人体有危害,其去除有重要意义.利用共沉淀法制备了Ce_(x)Zr_(1-x)O_(y)催化剂用于催化氧化去除甲醛,用XRD、SEM、N吸附-脱附、XPS表征催化剂,考察不同铈锆摩尔比的催化剂去除甲醛的活性强弱.结果表明:Ce_(0.8)Zr_(0.2)O_(y)常温催化氧化1.5 mg/m^(3)甲醛,反应前200 min内保持100%的去除率,连续反应12 h后甲醛去除率降至85%,5次焙烧再生后甲醛降解率为97%.结合物理化学表征分析发现,Ce物种的掺入能改变催化剂的形貌结构,带来更多化学吸附氧,进而提升催化剂的性能.催化剂失活原因是H_(2)O、Ce(CO_(3))_(2)占据活性位点,堵塞孔道及消耗活性组分.

Indoor formaldehyde is harmful to the environment and the human health,thus it becomes important to reduce formaldehyde.The Ce_(x)Zr_(1-x)O_(y)catalyst was prepared for formaldehyde removal by co-precipitation method and characterized by XRD,SEM,N_(2) adsorption-desorption and XPS to investigate the activity of catalytic formaldehyde with different cerium-zirconium molar ratio.The results showed that the formaldehyde with a concentration of 1.5mg/m3 could be catalytic oxidized by the Ce_(0.8)Zr_(0.2)O_(y)catalyst at room temperature,the removal rate maintained at 100%within 200 min and remained above 85%after 12 h of continuous reaction,and retained at 97%after five regeneration tests.Combined with the physicochemical characterization analysis,the Ce species can change the morphological structure of the catalyst,bring more chemical adsorbent oxygen,and then improve the performance of the catalyst.The reason for catalyst deactivation is that water and carbonate species occupy the active sites,block the pore and consume the active components.