Research On Electrocatalytic Oxidation Of Toluene In Gas Phase

With the development of industrialization and urbanization,Volatile organic compounds have serious impact on human life and health,so removing the volatile organic compounds in the atmosphere and reducing the emission of volatile organic compounds has received widespread attention.Among the technologies for removing pollutant gases,technologies such as biological decomposition,photocatalysis,thermal catalysis and adsorption have been developed,but each technology has certain defects and is difficult to be widely used.As an advanced oxidation technology,electrocatalytic oxidation technology has a wide range of applications in the field of pollutant removal in water,but the feasibility and effect of electrocatalytic oxidation technology in the removal of pollutant gases need to be studied.In this paper,the metal foam Ti is selected as the catalyst substrate,by designing an all-solid-state reaction cell for the electrocatalytic oxidation of gas phase toluene,the prepared catalyst was used to conduct room temperature electrocatalytic oxidation experiment of gas phase toluene,and the electrodeposition current of different lead oxide active layer electrodeposition experiments was explored.Electrodeposition temperature,electrodeposition time,and the pore size and thickness of the metal foam titanium substrate affect the catalytic activity,product selectivity,microscopic characteristics and electrochemical performance of the catalyst for electrocatalytic degradation of gas-phase toluene.The reasons for the improvement of the performance of the best electrode matrix are discussed in depth from the aspect of microscopic structure.The impact of different activity test experiments conditions such as the flow rate of the reaction gas,the humidity of the reaction gas,and the voltage applied to the reactor during the reaction.On this basis,the electrodeposition method was used to prepare PbO₂ electrodes modified by different content of polyethylene glycols.The microscopic morphology,electrochemical characteristics of different electrodes and the degradation effect of target pollutants on toluene were explored,and the modification of PbO₂ electrodes was realized and optimization.In this paper,the Sb-SnO₂ interface layer and Ti/Sb-SnO₂/PbO₂ electrode prepared by the electrodeposition-calcination method have been characterized by SEM,XRD,XPS,and EDS,etc.The results show that:1.The interface layer in the Ti/Sb-SnO₂/PbO₂ catalyst is Sb-SnO₂ nanospheres with uniform particles and densely arranged.PbO₂is aβ-PbO₂crystal form with a uniform and dense pyramid structure.2.Polyethylene glycol was added to the lead oxide electrodeposition solution,and the PbO₂ electrodeposition process was modified to prepare the Ti/Sb-SnO₂/PEG-PbO₂ catalyst.The addition of polyethylene glycol can have an impact on the crystallinity and surface morphology of lead oxide,so that the vapor-phase toluene oxidation elimination effect of the active crystal formβ-PbO₂ is improved.3.PbO₂ can be used to remove indoor gas phase pollutants.The experimental results show that the polyethylene glycol modified Ti/Sb-SnO₂/PbO₂ catalyst can achieve 90%removal efficiency of toluene under2 V voltage conditions,and the product carbon dioxide selectivity is high（96%）.Electrocatalytic oxidation technology has great potential for development in the field of indoor pollutant gas removal.4.The sandwich catalyst structure reactor with hydrogen ion exchange membrane as solid electrolyte can be used for indoor electrocatalytic oxidation.