商用V/W/Ti系脱硝催化剂表面SO<sub>3</sub>生成的反应机理

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Abstract Based on the serious impact of SO₃ generation and emission in coal-fired flue gas on the operation of power plants and the atmospheric environment, the SO₃ generation reaction kinetic and reaction mechanism in the surface of a typical commercial honeycomb V/W/Ti DeNO_x catalyst are studied. The reaction temperature and SO₂ were the key factors affecting the generation of SO₃ on the catalyst surface. SO₂-SO₃ conversion rate increased from 0.2% to 0.65% when the reaction temperature increased from 300℃ to 360℃ under 400×10^-6 SO₂ condition. After the reaction temperature reached to 400℃, the catalytic activity of V₂O₅ in catalyst surface increased more significantly, the SO₂-SO₃ conversion rate increased to 2.3%, and the apparent rate constant of SO₃ generation reaction also increased significantly by nearly 3times. The generation path of SO₃ on the catalyst surface is: SO₂ reacted with V⁵⁺-OH to generate intermediate products VOSO₄ and HSO₄^-, and then further reacted to generate SO₃. SO₂ mainly affected SO₃ generation through its adsorption and conversion on the catalyst surface, and its intrinsic kinetic reaction order is 0.52. The intrinsic kinetic reaction order of O₂ is 0, the generation reaction of SO₃ could be carried out without O₂. The presence of O₂ could promote SO₃ generation reaction, but did not change SO₃ generation path.

Key words： SCR catalyst SO₃ reaction kinetics in-situ Drift

Received: 02 December 2020

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X511

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	Articles by authors
	QING Meng-xia
	LIU Liang
	YIN Zi-jun
	LEI Si-yuan
	WANG Le-le
	SU Sheng
	XIANG Jun

Cite this article:

QING Meng-xia,LIU Liang,YIN Zi-jun等. Generation mechanism of SO₂ on the surface of commercial V/W/Ti DeNO_x catalysts[J]. CHINA ENVIRONMENTAL SCIENCECE, 2021, 41(7): 3161-3168.

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http://www.zghjkx.com.cn/EN/ OR http://www.zghjkx.com.cn/EN/Y2021/V41/I7/3161

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