Upgrading V2O5-WO3/TiO2 deNOx Catalyst with TiO2-SiO2 Support Prepared from Ti-Bearing Blast Furnace Slag

Abstract

Abstract:The study is devoted to developing a rather high-efficiency NH 3 -SCR (selective catalytic reduction) catalyst for NO x removal using TiO 2 -SiO 2 support made from blast furnace slag. Through adjusting hydrolytic pH value of TiOSO 4 solution obtained from acidolysis of slag with 70 wt. % H 2 SO 4 , a series of TiO 2 -SiO 2 mixed oxides was prepared to have different mass ratios of TiO 2 to SiO 2 . The supports are further impregnated with V 2 O 5 and WO 3 to make the SCR catalysts for NO x removal. Characterizing the catalysts show that silica and unavoidable impurities in support prepared from slag were responsible for maintaining their mesoporous structure and the enhancements in the acidity and reducible form of active species on the catalyst surface, which thus rendered the catalysts to have higher NO x reduction capability than catalyst using commercial TiO 2 . Furthermore, the low-cost catalyst prepared from slag-based TiO 2 support possesses good stability, and strong resistance to SO 2 and H 2 O poisoning, which are beneficial to practical deNO x applications.

Spherical Al-MCM-41 Doped with Copper by Modified TIE Method as Effective Catalyst for Low-Temperature NH3-SCR

“…This technology effectively operates in the temperature range of 300-400 • C in the presence of the catalysts based on V 2 O 5 -TiO 2 metal oxide systems [4]. The main advantages of these catalysts are their high selectivity to nitrogen and tolerance for SO x [5]. While the main disadvantages are narrow temperature range of effective operation and relatively high volatility of vanadium [6].…”

Review on the latest developments in modified vanadium-titanium-based SCR catalysts

“…Tran et al [116] prepared TiO2-SiO2 supports using Ti-bearing blast furnace slags (BFS). On loading with V2O5 and WO3, their low-temperature deNOx performance was significantly better than that of V2O5-WO3/TiO2.…”

Structure and performance of a V2O5–WO3/TiO2–SiO2 catalyst derived from blast furnace slag (BFS) for DeNOx

“…The detailed procedure for preparing the BFSbased supports can be found in our previous publications. 17,24 Commercial Ti and Si precursors were also used to synthesize TiO 2 -SiO 2 by co-precipitation and sol-gel methods. Following literature reports, 28,29 TiCl 4 and colloidal silica were used in co-precipitation, and the resulting precipitate was washed with distilled water and aqueous NH 3 to get S-CP-TiCl 4 .…”

“…Then the paste was dried at 110 C for 10 h and calcined at 600 C for 4 h to get the V 2 O 5 -WO 3 /TiO 2 -SiO 2 catalysts. 24 Four catalysts were prepared and denoted as BFS-1, BFS-2, CP-TiCl 4 and SG-Organic according to their different raw materials and synthesis methods used in preparing the TiO 2 -SiO 2 supports.…”

“…[5][6][7]19 As a matter of fact, the TiO 2 -SiO 2 support with different TiO 2 /SiO 2 ratios can be easily prepared in one step from BFS as shown by our recent work. 24 Besides providing low preparation cost as compared to methods based sol-gel or co-precipitation using pure chemicals, a distinguishing feature is its enabled high specic surface (427 m 2 g À1 ) and better DeNO x performance in a wide temperature window of 250-400 C for the prepared catalyst. However, the TiO 2 -SiO 2 support made from BFS has to contain some unavoidable dopant oxides such as Al 2 O 3 and Fe 2 O 3 to challenge the understanding of relationship between structure and function of the BFS-derived DeNO x catalysts.…”