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椰壳活性炭经硝酸氧化处理后做载体,采用浸渍法负载含SiO_2的复合氧化物,用做低温脱硝催化剂.在锰氧化物中添加Ti O2,可以提高催化剂的抗硫性能,但低温脱硝活性降低.然而在锰氧化物中添加SiO_2,不仅提高了催化剂的抗硫性能,而且也提高了脱硝活性.TEM结果表明加入SiO_2可以有效的减小复合氧化物晶粒尺寸,更提高了其在载体上的分散度.NH_3-TPD结果显示加入SiO_2后催化剂表面酸性显著增强.XPS分析发现加入SiO_2还增大了催化剂表面Mn~(4+)的相对含量.此外,经硝酸氧化处理过的椰壳活性炭,表面含氧基团增加,从而也大大提高了对NH_3及NO的吸附容量.在相同脱硝条件下,与原料活性炭负载的催化剂比较,硝酸氧化处理后的活性炭负载的催化剂具有更高的脱硝效率.
After the coconut shell activated carbon was treated by nitric acid oxidation, the impregnated SiO 2 -containing composite oxide was used as a low-temperature denitrification catalyst. Adding TiO 2 to the manganese oxide could improve the sulfur resistance of the catalyst but lower the denitrification activity at low temperature However, the addition of SiO 2 to manganese oxide not only improves the sulfur resistance but also enhances the denitrification activity.The TEM results show that the addition of SiO 2 can effectively reduce the grain size of the composite oxide and enhance its performance on the support .NH 3 -TPD results showed that the surface acidity of the catalyst was significantly enhanced by adding SiO 2 .XPS analysis found that the addition of SiO 2 also increased the relative content of Mn 4+ on the surface of the catalyst. In addition, the coconut shell activated carbon oxidized by nitric acid oxidation , The oxygen content of the surface increased, which also greatly increased the adsorption capacity of NH_3 and NO.Under the same denitration conditions, compared with the raw material activated carbon supported catalyst, activated carbon supported nitric acid oxidation catalyst has a higher denitrification efficiency .