Hg⁰ Removal Performance For The Catalyat Of Co₃O₄ Loading On Carbonated Plant Vessels

Mercury?Hg?is a pollutant with a global migration risk that poses a major threat to human health and the environment.Coal combustion is the main source of anthropogenic mercury emissions.Effective control of Hg content in flue gas,especially the content of element mercury?Hg⁰?,which is hardly soluble in water,is the key to coping with the increasingly serious mercury pollution in China.The catalytic oxidation method can realize the key conversion of Hg⁰ to Hg²⁺by means of the catalyst,and the effective removal of mercury can be realized by the existing pollution control equipment.Current research hotspots focus on supported catalysts,but current catalyst supports do not have regular pore structure,which will result in large mass transfer resistance and reaction resistance,limit the uniform dispersion of active components,and limit the mercury removal performance of the catalyst.Aiming at the problems of supported catalysts,the native wood biochar with three-dimensional connected pore structure was selected as the carrier,and the Hg⁰ performance was studied by metal Co modification.Then,the original wood carrier was used as the object to investigate the effect of hydrophilicity difference on the dispersion of active components,and the structure-effect relationship was constructed by characterization to study the reasons for the difference in mercury removal performance between the two catalysts.Finally,the preparation of Co₃O₄ nanorods and array-supported catalysts was explored to expose more active sites by directional growth of specific crystal face groups of catalysts,and to improve the mercury removal performance of the catalysts.Four kinds of carbon material carriers were used to carry Co for removal Hg⁰ research by impregnation method.Because the native wood biochar?BC?has an orderly pore structure,it can reduce the mass transfer resistance,promote the uniform dispersion of active components,and have good mercury removal.performance.On this basis,the effect of loading and temperature on the performance of Co/BC catalyst was studied.It was found that the loading was 31.32%,and the oxidation efficiency of Hg⁰ was up to 96%at 200°C.The characterization results show that the three-dimensional interconnected pore structure and large specific surface area of BC can promote the high dispersion of Co and expose more active sites,which constitute the"structural-effect relationship"of catalyst structure and activity.In order to promote the dispersion of active materials more effectively and improve the mercury removal performance of the catalyst,the hydrophilic properties of the carrier and the effect of the hierarchical porous structure on the mercury removal performance were studied.Studies have shown that wood impregnation method?Co/NWBC?can effectively exert the hydrophilicity advantage of the carrier,promote the uniform dispersion of Co₃O₄ on the surface and inside of the carrier,and the hierarchical porous structure can effectively reduce the mass transfer resistance.The catalyst Hg⁰ oxidation efficiency at 200°C up to 99%.Co/NWBC has good stability and regeneration performance,and its activity is reduced by 8%after 32 h.It can be restored to the original level after in-situ regeneration.In order to investigate the effect of Co₃O₄ nano-morphology on the oxidation efficiency of Hg⁰ catalyst,Co₃O₄ nanorods and Co₃O₄ nanosheet catalysts were synthesized in the conduit.By generating more oxygen vacancies,more active sites were exposed to improve the mercury removal performance of the catalyst.The preparation method of nanorods is optimized,and the successful anchoring of Co₃O₄ nanorods in the carrier channel is achieved,and the Hg⁰oxidation efficiency of the catalyst can reach 100%at 200°C.The uniform growth of the nanosheets in the pores of the carrier was initially achieved,and the mercury removal performance was initially tested.