Selective catalytic reduction over size-tunable rutile TiO2 nanorod microsphere-supported CeO2 catalysts

2016 ◽  
Vol 6 (12) ◽  
pp. 4478-4490 ◽  
Author(s):  
Kai Cheng ◽  
Weiyu Song ◽  
Ying Cheng ◽  
Jian Liu ◽  
Zhen Zhao ◽  
...  
Keyword(s):  
Selective Catalytic Reduction ◽  
Catalytic Reduction ◽  
Rutile Tio2 ◽  
Tio2 Nanorod ◽  
Morphology And Structure

Morphology and structure of TiO2 supports impact NH3-SCR performance of Ce/Ti catalysts significantly.

scholarly journals Catalytic Properties of Pd Modified Cu/SAPO-34 forNOxRemoval from Diesel Engine

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
J. C. Wang ◽  
H. Qiao ◽  
L. N. Han ◽  
Y. Q. Zuo ◽  
L. P. Chang ◽  
...  
Keyword(s):  
Hydrothermal Synthesis ◽  
Diesel Engine ◽  
Selective Catalytic Reduction ◽  
Catalytic Properties ◽  
Catalytic Reduction ◽  
Aging Treatment ◽  
No Conversion ◽  
Morphology And Structure ◽  
Skeleton Structure

The Cu/SAPO-34 catalysts with different Cu contents were prepared by in situ hydrothermal synthesis. The selected Cu/SAPO-34 was modified by impregnating 1 wt% Pd(NO3)3. The morphology and structure of the samples were characterized via XRD and SEM techniques. The effects of Cu contents and the Pd modification on the de-NOxactivity of the samples were investigated through the selective catalytic reduction by C3H6and NH3. The Cu contents do not change the skeleton structure of the SAPO-34 crystalline and the Cu/SAPO-34 catalysts with Cu/Si ratios of 0.05, 0.1, and 0.2 have better de-NOxactivity than other catalysts. The addition of Pd can improve the de-NOxactivity of the Cu/SAPO-34 catalysts. The maximum of NO conversion of samples with Pd could reach 90%. Besides, the effect of aging treatment for Cu/SAPO-34 catalysts with and without Pd on the de-NOxactivity was also investigated. The results indicated that the Cu/SAPO-34 catalysts modified by Pd have better antiaging performance than raw samples.

Highly dispersed MnOx–FeOx supported by silicalite-1 for the selective catalytic reduction of NOx with NH3 at low temperatures

2020 ◽  
Vol 10 (16) ◽  
pp. 5525-5534 ◽  
Author(s):  
Jialiang Gu ◽  
Bingjun Zhu ◽  
Rudi Duan ◽  
Yan Chen ◽  
Shaoxin Wang ◽  
...  
Keyword(s):  
Selective Catalytic Reduction ◽  
Low Temperatures ◽  
Catalytic Reduction ◽  
Highly Dispersed ◽  
Reduction Of Nox

MnOx–FeOx-Loaded silicalite-1 catalysts exhibit high NOx conversion at low temperatures.

Transition-metal-free catalytic hydroboration reduction of amides to amines

2020 ◽  
Vol 7 (21) ◽  
pp. 3515-3520
Author(s):  
Wubing Yao ◽  
Jiali Wang ◽  
Aiguo Zhong ◽  
Shiliang Wang ◽  
Yinlin Shao
Keyword(s):  
Transition Metal ◽  
Selective Catalytic Reduction ◽  
Catalytic Reduction ◽  
Value Added ◽  
Metal Free

The selective catalytic reduction of amides to value-added amine products is a desirable but challenging transformation.

Comparative analysis on the effects of diesel particulate filter and selective catalytic reduction systems on a wide spectrum of chemical species emissions

2018 ◽  
Author(s):  
Z. Gerald Liu ◽  
Devin R. Berg ◽  
Thaddeus A. Swor ◽  
James J. Schauer‡
Keyword(s):  
Diesel Engine ◽  
Selective Catalytic Reduction ◽  
Diesel Particulate Filter ◽  
Catalytic Reduction ◽  
Wide Spectrum ◽  
Chemical Species ◽  
Pollutant Emissions ◽  
Particulate Filter ◽  
Diesel Particulate ◽  
Aftertreatment Systems

Two methods, diesel particulate filter (DPF) and selective catalytic reduction (SCR) systems, for controlling diesel emissions have become widely used, either independently or together, for meeting increasingly stringent emissions regulations world-wide. Each of these systems is designed for the reduction of primary pollutant emissions including particulate matter (PM) for the DPF and nitrogen oxides (NOx) for the SCR. However, there have been growing concerns regarding the secondary reactions that these aftertreatment systems may promote involving unregulated species emissions. This study was performed to gain an understanding of the effects that these aftertreatment systems may have on the emission levels of a wide spectrum of chemical species found in diesel engine exhaust. Samples were extracted using a source dilution sampling system designed to collect exhaust samples representative of real-world emissions. Testing was conducted on a heavy-duty diesel engine with no aftertreatment devices to establish a baseline measurement and also on the same engine equipped first with a DPF system and then a SCR system. Each of the samples was analyzed for a wide variety of chemical species, including elemental and organic carbon, metals, ions, n-alkanes, aldehydes, and polycyclic aromatic hydrocarbons, in addition to the primary pollutants, due to the potential risks they pose to the environment and public health. The results show that the DPF and SCR systems were capable of substantially reducing PM and NOx emissions, respectively. Further, each of the systems significantly reduced the emission levels of the unregulated chemical species, while the notable formation of new chemical species was not observed. It is expected that a combination of the two systems in some future engine applications would reduce both primary and secondary emissions significantly.

Effect of Fe on the Selective Catalytic Reduction of NO by NH3 at Low Temperature over Mn/CeO2-TiO2 Catalyst

2012 ◽  
Vol 27 (5) ◽  
pp. 495-500 ◽  
Author(s):  
Da-Wang WU ◽  
Qiu-Lin ZHANG ◽  
Tao LIN ◽  
Mao-Chu GONG ◽  
Yao-Qiang CHEN
Keyword(s):  
Low Temperature ◽  
Selective Catalytic Reduction ◽  
Catalytic Reduction ◽  
Reduction Of No

Aplicação de Multi-Layer Perceptron para Previsão de Emissão de Gases derivados de Veículos a Diesel

2017 ◽  
Vol 3 (2) ◽  
pp. 1-11
Author(s):  
Luís Otávio Rigo Jr. ◽  
Jesuina Cássia Santiago de Araújo ◽  
Leandro Nogueira dos Santos ◽  
Mona Lisa Moura de Oliveira
Keyword(s):  
Selective Catalytic Reduction ◽  
Catalytic Reduction ◽  
Back Propagation ◽  
Multi Layer Perceptron

Fontes veiculares movidos a Diesel têm contribuido significativamente para o aumento da poluição atmosférica. A tendência mundial de utilizar motor Diesel se deve ao rendimento real alcançado por esta máquina (~34%), quando comparada com motores Otto (~26%). Em termos de poluição, tais motores apresentam a vantagem de emitir menor concentração de hidrocarbonetos e CO2. Por outro lado, o motor Diesel apresenta a desvantagem de emitir materiais particulados e NOx. Com fins de atender a legislação, tem sido incorporado aos veículos a Diesel um sistema catalítico, que injeta uréia nos gases de escape. Tal processo, conhecido como SCR (Selective Catalytic Reduction), tem por finalidade transformar NOx em N2 e H2O. Órgãos governamentais têm atuado como agentes controladores, exigindo dos fabricantes de motores soluções tecnológicas, capazes de reduzir os níveis de emissões destes poluentes. Essas soluções estão atreladas a uma série de testes experimentais onerosos. Tendo-se em vista que as taxas de emissão de NOx dependem de fatores que se correlacionam de forma complexa, faz-se necessário à utilização de ferramentas de simulação para prever tais taxas. Neste trabalho, foi utilizada uma Rede Neural Artificial, denominada Multi-Layer Perceptron, com algoritmo de aprendizado supervisionado Back Propagation, para estimar as taxas de emissão dos gases NOx, NH3 e N2O em veículos a Diesel. Os resultados mostraram que parâmetros de entrada (velocidade espacial, temperatura, concentração de NOx, de NH3, de O2 , de SO2 e de H2O) se correcionam fortemente com as taxas de emissão de NOx e NH3 na saída. Este fator foi comprovado pela grande capacidade de aprendizado das redes testadas, com erro médio próximo de 0,01 no conjunto de aprendizado. Os resultados sobre o conjunto de teste demonstraram, também, grande capacidade de generalização das redes. O melhor resultado encontrado foi de 2,9% para NOx e NH3 e de N2O de 5,1%. Estes resultados revelam que a RNA demonstrou ser um método eficiente para prever as taxas de emissão de poluentes em perímetro urbano e rodovias.

The synergistic effects between Ce and Cu in CuyCe1−yW5Ox catalysts for enhanced NH3-SCR of NOx and SO2 tolerance

2019 ◽  
Vol 9 (3) ◽  
pp. 718-730 ◽  
Author(s):  
Jian-Wen Shi ◽  
Yao Wang ◽  
Ruibin Duan ◽  
Chen Gao ◽  
Baorui Wang ◽  
...  
Keyword(s):  
Metal Oxides ◽  
Selective Catalytic Reduction ◽  
Low Temperatures ◽  
Catalytic Reduction ◽  
Synergistic Effects ◽  
Reduction Of No ◽  
Nh3 Scr ◽  
So2 Tolerance ◽  
Scr Of Nox

Non-manganese-based metal oxides are promising catalysts for the NH3-SCR (selective catalytic reduction) of NOx at low temperatures.

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