State Key Joint Laboratory of Environment Simulation and Pollution Control, Research Center for Eco-Environmental Sciences , Chinese Academy of Sciences , Beijing 100085 , China.
State Key Laboratory of Chemical Resource Engineering , Beijing University of Chemical Technology , Beijing 100029 , China.
Environ Sci Technol. 2018 Nov 6;52(21):12685-12696. doi: 10.1021/acs.est.8b04294. Epub 2018 Oct 22.
Transition metal (cerium and cobalt) doped γ-MnO (M-γ-MnO, where M represents Ce, Co) catalysts were successfully synthesized and characterized. Cerium-doped γ-MnO materials showed ozone (O) conversion of 96% for 40 ppm of O under relative humidity (RH) of 65% and space velocity of 840 L g h after 6 h at room temperature, which is far superior to the performance of the Co-γ-MnO (55%) and γ-MnO (38%) catalysts. Under space velocity of 840 L g h, the conversion of ozone over the Ce-γ-MnO catalyst under RH = 65% and dry conditions within 96 h was 60% and 100%, respectively, indicating that it is a promising material for ozone decomposition. XRD and HRTEM data suggested that Ce-γ-MnO formed mixed crystals consisting of α-MnO and γ-MnO with specific surface area increased from 74 m/g to 120 m/g compared to undoped γ-MnO, thus more surface defects were introduced. H-TPR, O-TPD, XPS, Raman, and EXAFS confirmed that Ce-γ-MnO exhibited more surface oxygen vacancies and surface defects, which play a key role during the decomposition of ozone. This study provides important insights for developing improved catalysts for gaseous ozone decomposition and promoting the performance of manganese oxide for practical ozone elimination.
过渡金属（铈和钴）掺杂 γ-MnO（M-γ-MnO，其中 M 代表 Ce、Co）催化剂被成功合成并进行了表征。铈掺杂 γ-MnO 材料在相对湿度（RH）为 65%和空间速度为 840 L g h 的条件下，室温下经过 6 小时后，对 40 ppm 的 O 的臭氧（O）转化率达到 96%，远优于 Co-γ-MnO（55%）和 γ-MnO（38%）催化剂的性能。在空间速度为 840 L g h 的条件下，Ce-γ-MnO 催化剂在 RH=65%和干燥条件下，96 小时内的臭氧转化率分别为 60%和 100%，表明其是一种很有前途的臭氧分解材料。XRD 和 HRTEM 数据表明，Ce-γ-MnO 形成了由 α-MnO 和 γ-MnO 组成的混合晶体，比未掺杂的 γ-MnO 的比表面积从 74 m/g 增加到 120 m/g，从而引入了更多的表面缺陷。H-TPR、O-TPD、XPS、拉曼和 EXAFS 证实，Ce-γ-MnO 具有更多的表面氧空位和表面缺陷，在臭氧分解过程中起着关键作用。本研究为开发用于气相臭氧分解的改进型催化剂提供了重要的见解，并促进了锰氧化物在实际臭氧消除中的性能。
