Research On Synthesis And Properties Of Low Temperature Thermocatalytic Material

Rapid social development had resulted in more volatile organic compound（VOC）emissions which affects the health of human sincerely.To resolve this problem,traditional manifold technologies,such as thermal combustion,catalysis,adsorptive recovery,absorption,biofiltration,etc.have been employed to remove VOC.Among them,catalytic degradation reaction driven by light and thermo energy is a more effective approach.To data,photocatalytic technology utilizing the sunlight energy has been investigated intensively because it carried out at mild reaction conditions.However,the photocatalysis has the relatively low quantum efficiency which restricted its industrial application.Low temperature thermocatalytic technology can be driven by both thermo and light,which is an ideal and cleaning catalytic reaction.Compared to photocatalysis,the low temperature thermal catalysis performed not only in the dark,but also under light irradiation since light absorption can convert to thermo over catalyst.Some thermocatalysts have wide light absorption ranged from Uv-light to irradiation light,exhibiting a potential application under sun-light irradiation due to its high sun-light energy utilization efficiency.Furthermore,compared to photocatalyst,the thermocatalysts usually exhibit high performance,which can degrade the pollutant in a short time;this makes thermocatalyst is more suitable for industrial application.Therefore,based on the shortcomings of thermocatalyst,make use of chemical treatment to increase its catalytic performance.The specific contents of the paper are as follows:1.Synthesis of oxygen vacancy Cr₂O₃Black Cr₂O₃ was obtained by heating chromic nitrate nonahydrate（Cr（NO₃）₃·9H₂O）in air at high temperature.The black Cr₂O₃ possesses an amount of oxygen vacancies.Oxygen vacancies enhance the absorbance intensity and extend the absorbance range up to 800nm.The balck Cr₂O₃ samples exhibit high performance in gas-phase organic pollution degradation both by thermo driven and sunlight light driven conditions.The surface oxygen vacancies faciliate the absorption of organic molecular,accelate the catalytic reaction.The A500 sample showed remarkably higher thermocatalytic activities,underlining the important roles played by oxygen vacancies.This study deepens the understanding of thermdegradation gas-phase organic pollution on defective surface,and may also provide a simple and cost-effective strategy for synthesizing efficient thermocatalysis for environmental remediation.2.Synthesis of oxygen vacancy of Cr doping Mn₃O₄Catalytic oxidation is an important method for degrading organic gaseous compounds,which has been researched intensively.Here,a high-performance Cr-doped Mn₃O₄ catalyst was synthesized by using a facile ultrasonic assistant method.The obtained sample exhibits abundant defects,small particles size and large specific surface area.The low crystallinity of Cr-doped Mn₃O₄ resulted from introducing Cr³⁺dopants makes the lattice oxygen atoms migrate easier,reducing the onset temperature of the reaction.Also,the dopant of Cr³⁺increases the specific surface area of Mn₃O₄,which is beneficial for the catalytic reaction carrying out.During the process of IPA（iso-Propyl alcohol）catalytic degradation,Cr-doped Mn₃O₄ exhibited improved thermocatalytic activity compared to pristine Mn₃O₄,which can be ascribed to the special of physical and chemical properties contributed by Cr³⁺dopants.