Catalytic degradation of benzene over non-thermal plasma coupled Co-Ni binary metal oxide nanosheet catalysts

Non-thermal plasma(NTP)has been demonstrated as one of the promising technologies that can degrade volatile organic compounds(VOCs)under ambient condition.However,one of the key challenges of VOCs degradation in NTP is its relatively low mineralization rate,which needs to be addressed by introducing catalysts.Therefore,the design and optimization of catalysts have become the focus of NTP coupling catalysis research.In thiswork,a series of two-dimensional nanosheet Co-Ni metal oxides were synthesized by microwave method and investigated for the catalytic oxidation of benzene in an NTP-catalysis coupling system.Among them,Co_(2)Ni_(1)O_(x)achieves 60%carbon dioxide(CO_(2))selectivity(SCO_(2))when the benzene removal efficiency(REbenzene)reaches more than 99%,which is a significant enhancement compared with the CO_(2)selectivity obtained without any catalysts(38%)under the same input power.More intriguingly,this SCO_(2)is also significantly higher than that of single metal oxides,NiO or Co_(3)O_(4),which is only around 40%.Such improved performance of this binary metal oxide catalyst is uniquely attributed to the synergistic effects of Co and Ni in Co_(2)Ni_(1)O_(x)catalyst.The introduction of Co_(2)Ni_(1)O_(x)was found to promote the generation of acrolein significantly,one of the key intermediates found in NTP alone system reported previously,suggest the benzene ring open reaction is promoted.Compared with monometallic oxides NiO and Co_(3)O_(4),Co_(2)Ni_(1)O_(x)also shows higher active oxygen proportion,better oxygenmobility,and stronger low-temperature redox capability.The above factors result in the improved catalytic performance of Co_(2)Ni_(1)O_(x)in the NTP coupling removal of benzene.

活性氧物种及其检测方法的研究进展

活性氧物种(Reactive Oxygen Species, ROS)是一种具有强反应活性的物质,主要包括超氧阴离子自由基、过氧化氢、单线态氧和羟基自由基等。作为氧化剂的氧气分子较为稳定,需要转化为高反应活性的活性氧物种后才能进一步与其他物质发生反应。在化学反应尤其是催化氧化反应中,活性氧的种类、生成、扩散行为等常常决定着整个反应的进行方向与速率;在生命科学领域,活性氧则参与能量转换、氧平衡等重要生理环节,与衰老、疾病等息息相关。而活性氧因其短寿命、强反应活性等,定性定量测试较为困难。选择合适的检测方式、提高检测的时空准确度,对于多相催化、环境化学、生命科学等领域研究有着重要意义。本工作对活性氧检测方法的基本原理、研究进展,以及在环境、生命领域以及多相催化的应用等方面进行对比与分析,比较各种手段的优缺点及适用范围。并对多相催化中氧物种的模拟及检测手段进行分析,展望了活性氧在催化氧化等领域未来的研究方向。要点:(1)介绍了活性氧物种的定义及种类。(2)分析了环境化学、生命科学中活性氧的检测原理与应用。(3)比较了活性氧不同检测手段的特点并讨论了方法的适用性。(4)讨论了多相催化中表面活性氧物种的研究方向。