One-step synthesized SO42–-TiO2 with exposed (001) facets and its application in selective catalytic reduction of NO by NH3

Review of Sulfur Promotion Effects on Metal Oxide Catalysts for NOx Emission Control

“…Besides, the exposed metal sites on metal oxides not only provided additional acid sites over sulfated catalysts but also were beneficial for the rate-determining step of NO activation. ,− Therefore, significant efforts have been made to explore the in-depth relationship between sulfur doping and metal oxides. (i) The synthesis of sulfated metal oxides with specific crystal planes could strengthen the interactions between sulfates and metal oxides on unary catalysts. ,, (ii) The fabrication of sulfated composited metal oxides could facilitate multiple redox cycles of the metal sites, − increase active oxygen storage, and improve successive oxygen mobility . (iii) The separation of acid and metal sites would facilitate NH 3 , NO, and O 2 adsorption and activation over the corresponding sites. ,, (iv) The construction of acid sites as sacrificial sites could functionally bind alkali , and heavy metals, further protecting the metal sites or resisting SO 2 adsorption .…”

“…(i) The synthesis of sulfated metal oxides with specific crystal planes could strengthen the interactions between sulfates and metal oxides on unary catalysts. 24,37,42 (ii) The fabrication of sulfated composited metal oxides could facilitate multiple redox cycles of the metal sites, 43−46 increase active oxygen storage, 47 and improve successive oxygen mobility. 48 (iii) The separation of acid and metal sites would facilitate NH 3 , NO, and O 2 adsorption and activation over the corresponding sites.…”

DeNOxperformance enhancement of Cu-based oxidesviaemploying a TiO2phase to modify LDH precursors

“…While NO + O 2 were imported for 30 min, the corresponding species appeared as follows: the absorbed N 2 O 4 (1745-1700 cm À1 ), bridged nitrate (1646 cm À1 and 1232 cm À1 ), bidentate nitrate (1547 cm À1 and 1516 cm À1 ), linear nitrite (1455 cm À1 ), monodentate nitrite (1424 cm À1 , 1393 cm À1 and 1108 cm À1 ), monodentate nitrate (1262 cm À1 ). 16,25,42,47 With an increase in the adsorption time of NH 3 , the bands of NO x species gradually reduced (1745-1700 cm À1 , 1646 cm À1 , 1547 cm À1 , 1455 cm À1 , 1424 cm À1 , 1393 cm À1 1262 cm À1 and 1108 cm À1 ), accompanied by the emergence of bands located at 1619 cm À1 and 1232 cm À1 , which were consistent with the asymmetric and symmetric bending vibrations of NH 3 adsorbed on Lewis acid sites (1619 cm À1 and 1232 cm À1 ). 13,48 Consequently, the NH…”