State Key Joint Laboratory of Environment Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China.
State Key Joint Laboratory of Environment Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; Center for Excellence in Regional Atmospheric Environment, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China; University of Chinese Academy of Sciences, Beijing 100049, China.
J Environ Sci (China). 2023 Dec;134:2-10. doi: 10.1016/j.jes.2021.12.016. Epub 2021 Dec 29.
Ground-level ozone is harmful to human beings and ecosystems, while room-temperature catalytic decomposition is the most effective technology for ozone abatement. However, solving the deactivation of existing metal oxide catalysts was caused by oxygen-containing intermediates is challenging. Here, we successfully prepared a two-dimensional NiFe layered double hydroxide (NiFe-LDH) catalyst via a facile co-precipitation method, which exhibited stable and highly efficient performance of ozone decomposition under harsh operating conditions (high space velocity and humidity). The NiFe-LDH catalyst with Ni/Fe = 3 and crystallization time over 5 hr (named NiFe-5) exhibited the best catalytic performance, which was well beyond that of most existing manganese-based oxide catalysts. Specifically, under relative humidity of 65% and space velocity of 840 L/(g·hr), NiFe-5 showed ozone conversion of 89% and 76% for 40 ppmV of O within 6 and 168 hr at room-temperature, respectively. We demonstrated that the layered structure of NiFe-LDH played a decisive role in its outstanding catalytic performance in terms of both activity and water resistance. The LDH catalysts fundamentally avoids the deactivation caused by the occupancy of oxygen vacancies by oxygen-containing species (HO, O, and O) in manganese-based oxide. This study indicated the promising application potential of LDHs than manganese-based oxide catalysts in removal of gaseous ozone.
地面臭氧对人类和生态系统有害，而室温催化分解是减少臭氧的最有效技术。然而，解决含氧中间产物导致现有金属氧化物催化剂失活的问题具有挑战性。在这里，我们通过简便的共沉淀法成功制备了二维 NiFe 层状双氢氧化物（NiFe-LDH）催化剂，该催化剂在苛刻的操作条件（高空间速度和高湿度）下表现出稳定且高效的臭氧分解性能。具有 Ni/Fe=3 和结晶时间超过 5 小时（命名为 NiFe-5）的 NiFe-LDH 催化剂表现出最佳的催化性能，远远超过大多数现有锰基氧化物催化剂。具体而言，在相对湿度为 65%和空间速度为 840 L/（g·hr）下，NiFe-5 在室温下分别在 6 和 168 小时内将 40 ppmV 的 O 的臭氧转化率提高到 89%和 76%。我们证明了 NiFe-LDH 的层状结构在其活性和耐水性方面对其出色的催化性能起着决定性作用。LDH 催化剂从根本上避免了含氧物种（HO、O 和 O）占据锰基氧化物中的氧空位而导致的失活。这项研究表明 LDH 比锰基氧化物催化剂在去除气态臭氧方面具有更大的应用潜力。
