NH 3 -SCR of NO over one-pot Cu-SAPO-34 catalyst: Performance enhancement by doping Fe and MnCe and insight into N 2 O formation

2017 ◽  
Vol 543 ◽  
pp. 247-256 ◽  
Author(s):  
Dong Zhang ◽  
Ralph T. Yang
Catalysts ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 55
Author(s):  
Katarzyna Świrk ◽  
Ye Wang ◽  
Changwei Hu ◽  
Li Li ◽  
Patrick Da Costa ◽  
...  

Copper and iron promoted ZrO2 catalysts were prepared by one-pot synthesis using urea. The studied catalysts were characterized by XRD, N2 physisorption, XPS, temperature-programmed desorption of NH3 (NH3-TPD), and tested by the selective catalytic reduction by ammonia (NH3-SCR) of NO in the absence and presence of water vapor, under the experimental conditions representative of exhaust gases from stationary sources. The influence of SO2 on catalytic performance was also investigated. Among the studied catalysts, the Fe-Zr sample showed the most promising results in NH3-SCR, being active and highly selective to N2. The addition of SO2 markedly improved NO and NH3 conversions during NH3-SCR in the presence of H2O. The improvement in acidic surface properties is believed to be the cause.


2021 ◽  
Author(s):  
Kartik Sau ◽  
Tamio Ikeshoji ◽  
Godwill Mbiti Kanyolo ◽  
Titus Masese

<b>Although the fascinatingly rich crystal chemistry of honeycomb layered oxides has been accredited as the propelling force behind their remarkable electrochemistry, the atomistic mechanisms surrounding their operations remain unexplored. Thus, herein, we present an extensive molecular dynamics study performed systematically using a refined set of inter-atomic potential parameters of <i>A</i><sub>2</sub>Ni<sub>2</sub>TeO<sub>6</sub> (where <i>A</i> = Li, Na, and K). We demonstrate the effectiveness of the Vashishta-Rahman form of the interatomic potential in reproducing various structural and transport properties of this promising class of materials and predict an exponential increase in cationic diffusion with larger interlayer distances. The simulations further demonstrate the correlation between broadened inter-layer (inter-slab) distances associated with the larger ionic radii of K and Na compared to Li and the enhanced cationic conduction exhibited in K<sub>2</sub>Ni<sub>2</sub>TeO<sub>6</sub> and Na<sub>2</sub>Ni<sub>2</sub>TeO<sub>6</sub> relative to Li<sub>2</sub>Ni<sub>2</sub>TeO<sub>6</sub>. Whence, our findings connect lower potential energy barriers, favourable cationic paths and wider bottleneck size along the cationic diffusion channel within frameworks (comprised of larger mobile cations) to the improved cationic diffusion experimentally observed in honeycomb layered oxides. Furthermore, we explicitly study the role of inter-layer distance and cationic size in cationic diffusion. Our theoretical studies reveal the dominance of inter-layer distance over cationic size, a crucial insight into the further performance enhancement of honeycomb layered oxides.</b><br>


2021 ◽  
Author(s):  
Kartik Sau ◽  
Tamio Ikeshoji ◽  
Godwill Mbiti Kanyolo ◽  
Titus Masese

<b>Although the fascinatingly rich crystal chemistry of honeycomb layered oxides has been accredited as the propelling force behind their remarkable electrochemistry, the atomistic mechanisms surrounding their operations remain unexplored. Thus, herein, we present an extensive molecular dynamics study performed systematically using a reliable set of inter-atomic potential parameters of </b><i>A</i><sub>2</sub><b>Ni</b><sub>2</sub><b>TeO</b><sub>6</sub><b> (where </b><i>A</i><b> = Li, Na, and K). We demonstrate the effectiveness of the Vashishta-Rahman form of the inter-atomic potential in reproducing various structural and transport properties of this promising class of materials and predict an exponential increase in cationic diffusion with larger inter-layer distances. The simulations demonstrate the correlation between broadened inter-layer (inter-slab) distances associated with the larger ionic radii of K and Na compared to Li and the enhanced cationic conduction exhibited in K</b><sub>2</sub><b>Ni</b><sub>2</sub><b>TeO</b><sub>6</sub><b> and Na</b><sub>2</sub><b>Ni</b><sub>2</sub><b>TeO</b><sub>6</sub><b> relative to Li</b><sub>2</sub><b>Ni</b><sub>2</sub><b>TeO</b><sub>6</sub><b>. Whence, our findings connect lower potential energy barriers, favourable cationic paths and wider bottleneck size along the cationic diffusion channel within frameworks (comprised of larger mobile cations) to the improved cationic diffusion experimentally observed in honeycomb layered oxides. Furthermore, we elucidate the role of inter-layer distance and cationic size in cationic diffusion. Our theoretical studies reveal the dominance of inter-layer distance over cationic size, a crucial insight into the further performance enhancement of honeycomb layered oxides.</b><br>


2015 ◽  
Vol 3 (31) ◽  
pp. 15854-15857 ◽  
Author(s):  
Ying Chen ◽  
Shuang Yang ◽  
Xiao Chen ◽  
Yi Chu Zheng ◽  
Yu Hou ◽  
...  

We report a one-pot solvothermal approach to synthesize cuboid shaped CH3NH3PbI3 single crystals. Growth and dissolution phenomena of perovskite crystals were discovered for the first time under solvothermal conditions.


2008 ◽  
Vol 22 (1) ◽  
pp. 90-108 ◽  
Author(s):  
Patsy Tremayne ◽  
Debra A. Ballinger

Ballroom dance has resurfaced worldwide as a highly popular competitive sport and might be added to Olympic medal competition for the 2012 London Games. This resurgence presents opportunities for sport psychologists to provide psychological-skills and performance-enhancement training for ballroom dancers at all competitive levels. Few sport psychologists have the personal experience, expertise, or an adequate knowledge base about the competitive-ballroom-dance environment to provide meaningful intervention strategies for participants. This article was developed to provide initial guidance for sport psychology professionals interested in working in this environment. An overview of the competitive-dance and ballroom-dance environment, strategies used by dance couples for enhanced mental preparation before and during dance competitions, and excerpts from an interview with an Australian championship-level couple provide readers insight into performance-enhancement strategies for DanceSport.


2013 ◽  
Vol 8 (11) ◽  
pp. 2739-2745 ◽  
Author(s):  
Xiuyi Zhu ◽  
Shenshen Jin ◽  
Shuxin Wang ◽  
Xiangming Meng ◽  
Changwei Zhu ◽  
...  

2020 ◽  
Vol 5 (46) ◽  
pp. 14685-14702
Author(s):  
Marwa A. A. Mohamed ◽  
Francisco Carrasco‐Marín ◽  
Noha A. Elessawy ◽  
Hesham A. F. Hamad

ChemCatChem ◽  
2020 ◽  
Vol 12 (19) ◽  
pp. 4871-4878
Author(s):  
Peiqiang Wang ◽  
Zhibin Li ◽  
Xiaotong Wang ◽  
Yongming Tong ◽  
Fulong Yuan ◽  
...  

2018 ◽  
Author(s):  
Ying Wei ◽  
Quanyou Feng ◽  
Hui Liu ◽  
Xiuling Wang ◽  
Dongqing Lin ◽  
...  

We focus on another kind of square-type unit nanogrids with starlike divergent extensibility. As a result, square windmill-like nanogrid <b>WG4</b> have been successfully synthesized by two different kinds of fluorene-based nanosynthons, namely I-shape nanosynthon and L-shape nanosynthon synthesis method. Besides <b>WG4</b>, triangle and hexagon windmill-like nanogrids (<b>WG3</b> and <b>WG5</b>) are also obtained via one-pot nanosynthesis of I-shape nanosynthon with <b>WG3</b> as the main product. For the L-shape nanosynthon synthetic method, the cyclization process possesses higher selectivity, resulting to an excellent yield for <b>WG</b>4. In addition, two stereoisomers of the triangle nanogrids, <i>cis-trans</i>-<b>WG3</b> and <i>cis-cis-</i><b>WG3</b>, were separated and characterized from the single-crystal X-ray diffraction and <sup>1</sup>H NMR analyses for getting insight into the configuration of the triangle nanogrids with the skeleton planarization for the <i>trans</i>-configuration and deplanarization for the <i>cis</i>-configuration.


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