V/AC催化剂改性机理及其CO脱硝活性

Modification mechanism and CO denitration activity of V/AC catalyst

为探明不同钒负载量对活性炭的改性机理和所制备催化剂的CO脱硝活性,选用椰壳活性炭为催化剂载体,先用硝酸活化活性炭,再用VOSO_(4)溶液浸渍并煅烧,制得V/AC系列催化剂。对V/AC进行SEM、EDS、BET、XRD和FTIR表征研究,探究V/AC改性机理,结果表明,催化剂表面活性组元均含有V及其氧化物。10%V负载量所制备催化剂能高效利用活性炭孔容并构建出新结构,比表面积和孔体积得以提高。V/AC系列催化剂表面均可观察到V_(2)O_(5)和V_(2)O_(3)活性组元。随负载量增加羧基和O-H官能团逐渐减少,过多负载量会破坏C-OH、C-O和C=O键。分析脱硝活性可知,具有较优理化参数的10%V负载量催化剂脱硝活性高于其他催化剂,同时15%V负载量催化剂的CO脱硝活性又高于5%V负载量催化剂。相关研究成果可为低温催化剂制备和CO脱硝技术应用提供借鉴。

In order to investigate the modification mechanism of activated carbon with different vanadium loads and the CO denitration activity of the prepared catalyst,coconut shell activated carbon was selected as catalyst carrier in this paper.A series of V/AC catalysts were prepared by using nitric acid activated,impregnation with VOSO_(4)solution,and calcination.V/AC catalysts were characterized by SEM,EDS,BET,XRD and FTIR.V/AC modification mechanism was researched.The results show that the surface active components of the catalyst contain Vanadium and Vanadium oxide.The pore volume of activated carbon is efficiently utilized with 10%V loading catalyst.A new structure is formed and the specific surface area and pore volume are increased with the 10%V loading catalyst.The active components of V_(2)O_(5)and V_(2)O_(3)is observed on the surface of V/AC catalysts.The carboxyl group and O-H functional group decrease gradually with the increase of V loading capacity,too much vanadium can break the C-OH,C-O and C=O bonds.The denitration activity of 10%V loading catalyst with better physical and chemical parameters is higher than others.The CO denitration activity of 15%V loading catalyst is higher than 5%V loading catalyst’s.The research results can provide reference for the preparation of low temperature catalysts and the application of CO denitration technology.