Preparation Of Monolithic Catalyst Over Copper Substrate And Catalytic Decomposition Of Toluene By Low Temperature Plasma

Volatile organic compound(VOC)is one of the major pollution which caused environmental problems.Low temperature plasma technique has been attracting close attention recently due to its advantages such as convenient to start-up and shutdown,low-cost and universal to a wide range of VOCs.But the low purification efficiency and selectivity are the bottlenecks that constrain its industrial application.The combination of low temperature plasma technology and catalyst technology coupling is an effective way to solve this problem.The development of high-performance and low-cost catalyst is the hotspot in this field.At the same time,the form of catalyst loading in reactor is also important for industrialization.In this thesis,we tried to develop a high-performance monolithic catalyst on copper substrate which is simple,green,controllable and easy to scale-up.The application in plasma-catalytic oxidation of toluene was also studied.The main content of this thesis is as follows:(1)Copper oxide nanowire structure on a foamed Cu substrate is made through simple thermal oxidation to get CuO/Cu foam catalyst.It is found that the prepared CuO nanowires are single crystals,and the length of CuO nanowires can be controlled by changing the duration of heat treatment.The toluene conversion rate was significantly improved when CuO/Cu foam was filled in the reator compared with that of empty tube.This advantages was more obvious at lower energy density.The effect is due to the synergy of low temperature plasma and catalysis.(2)The Co-Mn@CuO 1D core-shell nanowires were obtained through the thermal oxidation and dipping method on copper mesh,and the activity of low temperature plasma-catalysis oxidation of toluene was also studied.It showed that the prepared Co-Mn@CuO nanowires were 1D core-shell structure.CuO nanowires are the core while Mn,Co and a few of Cu disperse in the shell layer.Its thickness and distribution can be adjusted by the immersion time and the concentration of the Co-Mn mixed solution.The formation of the core-shell structure may be due to the growth of Co-Mn oxide and the dissolution of CuO,which lead to the diffusion of Cu ions.The result showed that the low temperature plasma reactor was filled with CuO nanowires and Co-Mn@CuO core-shell nanowires.The activity was improved obviously due to the low temperature plasma-catalyzed synergistic effect.The order of activity was Co-Mn@CuO 1D core-shell nanowires(annealing)> Co-Mn@CuO 1D core-shell nanowires>CuO nanowires>tube>Cu mesh.In conclusion,the developed monolithic catalysts over copper mesh showed a synergistic effect in low temperature plasma-catalysis oxidation of toluene,particularly at low-energy density.The mechanism of action is worth to be further studied.The monolithic catalyst is potential in real application due to the advantages of simple,green,economical,controlled,easy to scale-up and etc.