Novel Fe‐W‐Ce Mixed Oxide for the Selective  Catalytic Reduction of NOx with NH3 at Low  Temperatures

Ståhl, Anna; Zhong, Wang; Schwämmle, Tobias; Ke, Jun; Li, Xuebing

doi:10.3390/catal7020071

Cited by 25 publications

(9 citation statements)

References 47 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Ge–Ce–W catalysts showed a broad working temperature window (200–470 °C) due to the optimized surface distribution of Ce and W after Ge addition and the synergistic effects among Ge, Ce, and W species . Fe–Ce–W oxide catalysts showed an excellent working temperature window (200–500 °C) because Fe was highly dispersed and formed a solid solution in the Ce oxide lattice . Cu–Ce–W catalysts showed more Cu 2+ , Ce 3+ , W 5+ , and chemisorbed oxygen species while following both E-R and L-H mechanisms .…”

Section: Metal Oxide Catalystsmentioning

confidence: 99%

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

et al. 2019

View full text Add to dashboard Cite

Selective catalytic reduction with NH 3 (NH 3 −SCR) is the most efficient technology to reduce the emission of nitrogen oxides (NO x ) from coal-fired industries, diesel engines, etc. Although V 2 O 5 −WO 3 (MoO 3 )/TiO 2 and CHA structured zeolite catalysts have been utilized in commercial applications, the increasing requirements for broad working temperature window, strong SO 2 /alkali/heavy metal-resistance, and high hydrothermal stability have stimulated the development of new-type NH 3 −SCR catalysts. This review summarizes the latest SCR reaction mechanisms and emerging poisonresistant mechanisms in the beginning and subsequently gives a comprehensive overview of newly developed SCR catalysts, including metal oxide catalysts ranging from VO x , MnO x , CeO 2 , and Fe 2 O 3 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.

show abstract

Section: Metal Oxide Catalystsmentioning

confidence: 99%

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

et al. 2019

View full text Add to dashboard Cite

show abstract

“…On the contrary, the most widely method for preparing solids is the sol-gel followed by the hydrothermal method [6,8]. This route involves one-pot hydrothermal process, through the processing of metal salt or metal alkoxide precursors, which is not time consuming for the practical applications.…”

Section: Epr Measurementsmentioning

confidence: 99%

Styrene Oxidation to Valuable Compounds over Nanosized FeCo-Based Catalysts: Effect of the Third Metal Addition

et al. 2017

View full text Add to dashboard Cite

Nanosized FeCo-based solids were prepared via distinct preparation procedures. The catalytic performances of the solids for styrene oxidation in the presence of hydrogen peroxide were evaluated. The addition of promoters in FeCo such as Sn, Mo, or Cu was also investigated. The catalysts were characterized with XRD, Raman spectroscopy, TEM, chemical analyses, EPR and SEM-EDS. Of these solids obtained via four different methods, the catalyst prepared via the NC and CM procedures enabled a partial incorporation of the Sn into the FeCo matrix forming a very active phase, namely the Heusler alloy. This was ascribed to the high initial dispersion of Sn as a promoter into the FeCo matrix, which led to available FeCoSn (FCS) particles well dispersed and stable on the catalyst surface. In the case of incorporating Mo or Cu to the nanosized FeCo catalyst, a poor stability towards leaching was observed when operating under the same reaction conditions. Cu was much less active than both Sn and Mo, mainly leading to acetophenone, ethylbenzene, 2-phenyl ethanol, 2-phenyl acetic acid, and 2-phenyl acetaldehyde products. The best catalytic results under the optimized reaction conditions, especially at 50 • C and styrene/H 2 O 2 molar ratio of 1 were achieved with nanosized FCS. This solid had a conversion of ca. 70% and selectivity for aldehydes of ca. 27%, and the selectivity for the condensation products was 29%.

show abstract

“…Compared with MgAl-LDO (CP), the small peak shift toward higher binding energies for both Mg (0.4 eV) and Al (0.3 eV) suggested a decrease in the oxidation state of the transition metals [32]. From the findings, the XPS peak migration of metal oxides caused the lattice distortion of metal, which resulted in more defective sites and active sites [33,34]. Additionally, the introduction of oxygen vacancies was balanced by the lowered valence state of Mg and Al sites.…”

Section: Introductionmentioning

confidence: 97%

High CO Methanation Performance of Two-Dimensional Ni/MgAl Layered Double Oxide with Enhanced Oxygen Vacancies via Flash Nanoprecipitation

Zhang

et al. 2018

Catalysts

View full text Add to dashboard Cite

As a methanation tool, two-dimensional (2D) carrier-loaded Ni has attracted the attention of many researchers. We successfully prepared 2D MgAl layered double oxides (LDO) carriers via flash nanoprecipitation (FNP). Compared to the LDO samples prepared by conventional co-precipitation (CP), the 2D MgAl-LDO (FNP) has more oxygen vacancies and more exposed active sites. The Ni/MgAl-LDO (FNP) catalyst demonstrates a CO conversion of 97%, a CH 4 selectivity of 79.8%, a turnover frequency of 0.141 s −1 , and a CH 4 yield of 77.4% at 350 • C. The weight hourly space velocity was 20,000 mL·g −1 ·h −1 with a synthesis gas flow rate of 65 mL·min −1 , and a pressure of 1 atm. A control experiment used the CP method to prepare Ni/MgAl-LDO. This material exhibits a CO conversion of 81.1%, a CH 4 selectively of 75.1%, a TOF of 0.118 s −1 , and a CH 4 yield of 61% at 450 • C. We think that this FNP method can be used for the preparation of more 2D LDO catalysts. molecular sieve catalysts (Ni/3D-MCM-41), the Ni/2D-SiO 2 catalyst showed remarkable catalytic activity with high CO conversion and CH 4 selectivity at 450 • C.Natural mineral vermiculite (VMT) with a 2D structure as a catalyst support was reported [12]. Li et al. [13] attempted to expand multilayered vermiculite as a catalyst support and successfully synthesized NiO/VMT composite by microwave irradiation-assisted synthesis (MIAS). The Ni/VMT (MIAS) resulted in highly dispersed active sites and exhibited excellent catalysis performance, including a 99.6% CO conversion and 93.8% CH 4 selectivity at 400 • C. Zhang et al. [14] synthesized a 2D plasma-treated vermiculite (PVMT) with low Ni loading (0.5 wt %) via a plasma irradiation method (PIM). The PIM-Ni/PVMT exhibited superior catalytic performance, and the plasma-treated catalyst PIM-Ni/PVMT achieved a CO conversion of 93.5% and a turnover frequency (TOF) of 0.8537 s −1 at a temperature of 450 • C and a pressure of 1.5 MPa.Other 2D catalysts for CO methanation include 2D Ni-based layered double oxides (LDO) from layered double hydroxides (LDH). These systems are popular because of their high Ni dispersibility [15,16]. NiAl-LDO offers excellent activity for methanation under 2.0 MPa and 527 • C. NiAl-LDO catalysts with 56.5 wt % Ni achieved 97% CO conversion in a pilot methanation unit. Bian et al.[17] synthesized a NiAl-LDO catalyst that displayed high catalytic stability due to high Ni dispersion and strong resistance to coke deposition versus the impregnated catalyst. Nearly 100% CO conversion was achieved with reaction temperatures between 400 and 500 • C with a weight hourly space velocity (WHSV) of 300,000 mL·g −1 ·h −1 .Mg adulteration can also improve the anti-coke ability of Ni-based catalysts. Li et al.[18] synthesized Ni-Mg-Al LDO (i.e., NiMg8, Ni/Mg = 1/8) via a co-precipitation method. The as-obtained catalyst with 11 wt % Ni had the best CO methanation performance due to the small size of Ni particles and high Ni dispersion. The NiMg8 had excellent performance: 99.8% CO conversion and 73.6% CH 4 selectivi...

show abstract

Novel Fe‐W‐Ce Mixed Oxide for the Selective Catalytic Reduction of NOx with NH3 at Low Temperatures

Cited by 25 publications

References 47 publications

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

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

Styrene Oxidation to Valuable Compounds over Nanosized FeCo-Based Catalysts: Effect of the Third Metal Addition

High CO Methanation Performance of Two-Dimensional Ni/MgAl Layered Double Oxide with Enhanced Oxygen Vacancies via Flash Nanoprecipitation

Contact Info

Product

Resources

About

Novel Fe‐W‐Ce Mixed Oxide for the Selective Catalytic Reduction of NOx with NH3 at Low Temperatures

Cited by 25 publications

References 47 publications

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

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

Styrene Oxidation to Valuable Compounds over Nanosized FeCo-Based Catalysts: Effect of the Third Metal Addition

High CO Methanation Performance of Two-Dimensional Ni/MgAl Layered Double Oxide with Enhanced Oxygen Vacancies via Flash Nanoprecipitation

Contact Info

Product

Resources

About

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

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