Enhancement of performance and sulfur resistance of Si-doped V/W/Ti using sulfation for selective catalytic reduction of NO_x with ammonia

ABSTRACT

This study investigated the SO₂ resistance enhancement factors of silica with the V/SiW/TiO₂ catalyst prepared using various precursors. BET, XPS, H₂-TPR, DRIFT, and temperature-programmed desorption (TPD) were used to analyze the physical and chemical properties of the catalyst. The catalyst prepared with Dimethoxydimethylsilane (DMDMS), from various precursor silica fabricated to improve SO₂ resistance, demonstrated the highest increase in resistance. The SO₂ resistance improvement factor was confirmed to form Si²⁺(Si-O-Ti) species in the optimised V/SiW/TiO₂ catalyst; the incoming SO₂ was converted to Si(SO₄). The formation of Si(SO₄) increased the number of adsorbed sites for adsorbed NH₃, in the form of SO₄-NH₃ to increase the amount of the reducing agent of NH₃-SCR, and improve denitrification efficiency. It was optimal to increase the VO_x surface density whilst increasing the ratio of the Si²⁺ species, the Si-sulfate site of SiW/TiO₂ support, to improve denitrification performance and SO₂ resistance concurrently.

Highlights

• The SO₂ resistance improvement factor was confirmed to form Si²⁺(Si-O-Ti) species.

• In the optimised V/SiW/TiO₂ catalyst; the incoming SO₂ was converted to Si(SO₄).

• The formation of Si(SO₄) increased active sites for adsorbed NH₃, in the form of SO₄-NH₃ to improve denitrification efficiency.

GRAPHICAL ABSTRACT

KEYWORDS:

• NH₃-SCR
• SO₂ resistance
• DMDMS precursor
• Si²⁺(Si-O-Ti)
• Si-sulfate

Acknowledgements

This work was conducted under the framework of Research and Development Programme of the Korea Institute of Energy Research (KIER) (C0-2425).

Data availability statement

The data that support the findings of this study are available from the corresponding author, [ S.C. Hong], upon reasonable request.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by Korea Institute of Energy Research: [Grant Number C0-2425].