Selective catalytic reduction with NH3 (NH3-SCR) is the most efficient technology to reduce the emission of nitrogen oxides (NOx) from coal-fired industries, diesel engines, etc. Although V2O5-WO3(MoO3)/TiO2 and CHA structured zeolite catalysts have been utilized in commercial applications, the increasing requirements for broad working temperature window, strong SO2/alkali/heavy metal-resistance, and high hydrothermal stability have stimulated the development of new-type NH3-SCR catalysts. This review summarizes the latest SCR reaction mechanisms and emerging poison-resistant mechanisms in the beginning and subsequently gives a comprehensive overview of newly developed SCR catalysts, including metal oxide catalysts ranging from VOx, MnOx, CeO2, and Fe2O3 to CuO based catalysts; acidic compound catalysts containing vanadate, phosphate and sulfate catalysts; ion exchanged zeolite catalysts such as Fe, Cu, Mn, etc. exchanged zeolite catalysts; monolith catalysts including extruded, washcoated, and metal-mesh/foam-based monolith catalysts. The challenges and opportunities for each type of catalysts are proposed while the effective strategies are summarized for enhancing the acidity/redox circle and poison-resistance through modification, creating novel nanostructures, exposing specific crystalline planes, constructing protective/sacrificial sites, etc. Some suggestions are given about future research directions that efforts should be made in. Hopefully, this review can bridge the gap between newly developed catalysts and practical requirements to realize their commercial applications in the near future.

Selective Catalytic Reduction of NOx with NH3 by Using Novel Catalysts: State of the Art and Future Prospects.

Recent progress in metal-doped TiO2, non-metal doped/codoped TiO2 and TiO2 nanostructured hybrids for enhanced photocatalysis

Mechanistic aspects of NH3-SCR reaction over CeO2/TiO2-ZrO2-SO42− catalyst: In situ DRIFTS investigation

Elemental mercury removal from coal-fired flue gas using recyclable magnetic Mn-Fe based attapulgite sorbent

Low temperature NH3 selective catalytic reduction (NH3-SCR) technology is an efficient and economical strategy for cutting NOx emissions from power-generating equipment. In this study, a novel and ...

Tourmaline-Modified FeMnTiOx Catalysts for Improved Low-Temperature NH3-SCR Performance

Cerium-loaded MnOx/attapulgite catalyst for the low-temperature NH3-selective catalytic reduction

Three-dimensional g-C3N4/MWNTs/GO hybrid electrode as electrochemical sensor for simultaneous determination of ascorbic acid, dopamine and uric acid.

Novel cerium-loaded MnTiOx/attapulgite (Ce/MnTiOx/ATP) and cerium-doped MnTiOx/attapulgite (Ce–MnTiOx/ATP) catalysts for low-temperature selective catalytic reduction of nitrogen oxides (NOx) with ammonia (NH3-SCR) were synthesized by co-precipitation methods. The results of catalytic activity testing for the as-prepared Ce–MnTiOx/ATP and Ce/MnTiOx/ATP indicated that the Ce–MnTiOx/ATP catalyst exhibited better catalytic performance with over 80% NOx conversion within a wide temperature window between 170 and 350°, and the highest NOx conversion attained for the Ce–MnTiOx/ATP catalyst was 97.5%. A series of characterization illustrated that the Ce–MnTiOx/ATP catalyst exhibited a higher specific surface area, oxygen vacancy, redox ability, and acid site as compared to that of the Ce/MnTiOx/ATP catalyst. The performance tests showed that the Ce–MnTiOx/ATP catalyst exhibited not only better SO2 & H2O resistance but also higher N2 selectivity and good stability. Therefore, the Ce–MnTiOx/ATP catalyst was testified to be a promising catalyst for NH3-SCR.

https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S088429141800242X

Cerium modified MnTiOx/attapulgite catalyst for low-temperature selective catalytic reduction of NOx with NH3

Two-dimensional MoS2/Mn-MOF/multi-walled carbon nanotubes composite material for high-performance supercapacitors

A series of Ce-doped LaMnO3 (La1-xCexMnO3) were prepared and were tested for gaseous toluene oxidation in order to investigate the effect of cerium doping in LaMnO3 on activity under photothermal conditions. It was found that the activity and CO2 yield of the catalyst can be effectively increased when x = 0.25. A group of characterization is used to characterize the morphology, composition, and physical properties of the as-prepared catalysts. Results show that the Ce-doped LaMnO3 can form coexistence of La1-xCexMnO3 and CeO2, the reaction of CeO2/La1-xCexMnO3 under photothermal conditions follows the Mars-van Krevelen redox cycle mechanism, and the prepared CeO2/La1-xCexMnO3 can form a highly efficient Z-scheme heterojunction, which can enhance the electrons transfer speed of the catalyst. Moreover, in the photothermal catalytic degradation, lattice oxygen is the most important active substance, a small amount of cerium doping can increase the lattice oxygen content of perovskite and increase the activity of the reaction.

Aijuan Xie

Papers

Cerium-loaded MnOx/attapulgite catalyst for the low-temperature NH3-selective catalytic reduction

Three-dimensional g-C3N4/MWNTs/GO hybrid electrode as electrochemical sensor for simultaneous determination of ascorbic acid, dopamine and uric acid.

Cerium modified MnTiOx/attapulgite catalyst for low-temperature selective catalytic reduction of NOx with NH3

Two-dimensional MoS2/Mn-MOF/multi-walled carbon nanotubes composite material for high-performance supercapacitors

Direct Z-scheme La 1-x Ce x MnO 3 catalyst for photothermal degradation of toluene