Solvothermal Method Prepare Metal-Organic Framework Catalyst ?Ni-MOF? Applied For Selective Catalytic Reduction Of NOx With NH₃

Nitrogen oxides?NOx?are the main pollutants in the atmosphere.Although China has some control method of decreasing NOx emissions,truly effective green emissions has not been achieved.Reducing NO emission has become the focus of our country's ecological protection.Among many pollution control technologies,selective catalytic reduction with ammonia?NH₃-SCR?has been most widely used as a high deNOx method.The key of SCR Reaction conditions is the characterization of catalyst,which determines the deNOx efficiency of catalytic reactions.Metal-organic framework compounds?MOFs?possess regular pore structure,large specific surface area,and coordinated unsaturated metal active sites,which have been used in many fields such as gas separation,storage,catalysis and so on.Although there are few reports about the application of MOFs in gas-phase catalysis,it has been considered to be a promising catalyst in the field of denitrification.The current research is not only limited to the preparation of a single metal active site MOFs material,but also includes the construction of MOFs with bimetallic active sites.For bimetallic MOFs,the effect of synergy between their metal and electronic structure changes can further improve the catalytic performance of MOFs.In this paper,Ni-MOF and Cu⁺/Ni-MOF catalysts were successfully synthesized by solvothermal method and low-temperature loading method.They were used as NH₃-SCR catalysts to remove nitric oxide in simulated flue gas.The physical chemistry of catalysts was examined through various characterization methods.The results are as follows:1.Ni-MOF catalyst was successfully prepared by direct solvothermal synthesis.By optimizing the conditions including solvent,ligand,active temperature,it came to the conclusion that with DMF as solvent,H₂BDC as ligand after vacuum drying at 120?,a pure Ni-MOF material with good crystal structure was obtained with a yield of 97.2%.2.The material was purged with nitrogen at different temperatures for two hours.The pre-treated activated materials were applied to the NH₃-SCR reaction to remove NO.The active temperature had an important effect on the physical and chemical properties of materials.The material activated at 220? had the best NH₃-SCR efficiency.At 275-440?,the NO conversion rate up to 92%.The results of thermal stability analysis showed that the catalyst still kept its own good thermal stability at 440?.3.Cu⁺/Ni-MOF catalysts were prepared by low temperature loading method.The EDX and XPS characterization proved Cu⁺ions had been introduced successfully.The introduction of Cu⁺did not change the framework structure of the catalyst.At the same time,compared with the single metal?Ni?material,the denitrification efficiency increased in the NH₃-SCR reaction.