VPO/TiO2催化剂表面酸性位调控及低温NH3-SCR脱硝性能研究

陈宜华; 王攀; 孟凡禹; 陈雅芬; 张铭; 贾勇

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中国环境科学 ›› 2023, Vol. 43 ›› Issue (4) : 1558-1566.

大气污染与控制

VPO/TiO₂催化剂表面酸性位调控及低温NH₃-SCR脱硝性能研究

陈宜华, 王攀, 孟凡禹, 陈雅芬, 张铭, 贾勇

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The optimization of surface acidity VPO/TiO₂ catalyst and its low-temperature NH₃-SCR denitration performance

CHEN Yi-hua, WANG Pan, MENG Fan-yu, CHEN Ya-fen, ZHANG Ming, JIA Yong

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摘要

采用HCl调控负载型钒磷氧(VPO/TiO₂)催化剂的表面酸性,用于研究VPO/TiO₂催化剂的NH₃-SCR脱硝性能.结果表明:在HCl/V物质的量比为3~5:1范围内,催化剂的脱硝活性最高,当反应温度达到200℃时脱硝效率接近100%.表征结果表明:HCl的添加能提高催化剂的结晶度,HCl的调控使得VPO/TiO₂催化剂的比表面积略有增加.同时,也使得VPO/TiO₂催化剂中活性组分V⁴⁺的量从38%逐渐升高至46%,提高了催化剂的氧化还原性能.此外,不同HCl/V物质的量比的催化剂中化学吸附氧的相对含量随着HCl加入量的增加而提高.吡啶红外测试结果显示:HCl能影响催化剂酸性位点,HCl/V物质的量比=5的催化剂Lewis酸含量最高,总酸量为0.84×10^-4mol/g.数据拟合进一步表明,所有VPO/TiO₂催化剂的低温脱硝活性均与弱Lewis酸量呈正相关(相关系数>0.9),与活性测试相吻合.

Abstract

HCl was used to modify the surface acidity of supported vanadium phosphorus oxide (VPO/TiO₂) catalysts for NH₃-SCR. The results show that the denitration activity of catalyst was the highest with HCl/V molar ratio of 3~5:1, and the efficiency was almost 100% when the reaction temperature reached 200℃. It was found that the addition of HCl improved the crystallinity of the catalyst, and the modification of HCl could slightly increase the specific surface area of the VPO/TiO₂ catalyst. Meanwhile, the amount of active component V⁴⁺ in the VPO/TiO₂ catalyst was gradually increased from 38% to 46%, which improved the redox performance of the catalyst. In addition, the relative content of chemisorbed oxygen in the catalysts with different HCl/V molar ratios increased with the increase of HCl addition amount. The pyridine infrared test results show that HCl affected the acid site of the catalyst, and the catalyst with HCl/V molar ratio=5 had the highest Lewis acid content as 0.84×10^-4mol/g. Data fitting results further demonstrate that the low-temperature denitration activities of all VPO/TiO₂ catalysts were positively correlated with the amount of weak Lewis acid (correlation coefficient > 0.9), which is consistent with the results of activity test.

导出引用

陈宜华, 王攀, 孟凡禹, 陈雅芬, 张铭, 贾勇. VPO/TiO₂催化剂表面酸性位调控及低温NH₃-SCR脱硝性能研究[J]. 中国环境科学. 2023, 43(4): 1558-1566

CHEN Yi-hua, WANG Pan, MENG Fan-yu, CHEN Ya-fen, ZHANG Ming, JIA Yong. The optimization of surface acidity VPO/TiO₂ catalyst and its low-temperature NH₃-SCR denitration performance[J]. China Environmental Science. 2023, 43(4): 1558-1566

中图分类号： X701

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