scholarly journals Green Synthesis of a Cu/SiO2 Catalyst for Efficient H2-SCR of NO

2019 ◽  
Vol 9 (19) ◽  
pp. 4075 ◽  
Author(s):  
Esteban Gioria ◽  
F. Marchesini ◽  
Analía Soldati ◽  
Antonella Giorello ◽  
Jose Hueso ◽  
...  

In this work, the synthesis of Cu/SiO2 catalysts starting from pre-formed copper nanoparticle (CuNP) colloidal suspensions was carried out. Two different protocols for the CuNP synthesis were tested: (i) a green approach using water as solvent and ascorbic acid as reducer and stabilizing agent, and (ii) a second solvothermal method involving the use of diethylene glycol as solvent, sodium hypophosphite (NaH2PO2) as reducer, and polyvinylpyrrolidone (PVP) and cetyltrimethylammonium bromide (CTAB) as stabilizing agents. In addition, and for the sake of comparison, a third catalyst was prepared by solid state conventional grinding of CuO with SiO2. The catalysts were tested in the environmentally relevant catalytic reduction of NOX with H2, in a temperature range from 300 to 500 °C. The catalysts were characterized by X-ray diffraction (XRD), temperature programmed reduction (TPR) cycles, Raman spectroscopy, and N2 adsorption for specific surface BET measurements. From these techniques CuO and Cu(0) species were detected depending on the synthesis protocol. CuNP size and size distribution in the colloid suspensions were determined by transmission electronic microscopy (TEM). The catalyst prepared from the aqueous suspension (CuAsc/SiO2) exhibited higher NO conversion (100%) and selectivity (85%) toward N2 at the lower reaction evaluated temperature (300 °C). The CuCTAB/SiO2 catalyst obtained by the solvothermal approach showed activity at high reaction temperature (400 °C) preferentially. The metal–support mechanical mixture exhibited a negligible response at low temperature and low conversion (68%) and selectivity (88%) at 500 °C. Nanoparticle size and distribution on the support, together with the metal–support interaction, were postulated as the most plausible parameters governing the catalytic performance of the different Cu/SiO2 materials.

2012 ◽  
Vol 518-523 ◽  
pp. 281-284
Author(s):  
Qing Ye ◽  
Hai Ping Wang ◽  
Hai Xia Zhao ◽  
Shui Yuan Cheng ◽  
Tian Fang Kang

Cu supported on acid-treated sepiolite catalysts (xCu/H-Sep, x = 0  20.0 wt%) or Cu-Fe mixed supported on acid-treated sepiolite catalysts (yFe-10Cu/H-Sep, y = 0  20.0 wt%) were prepared by the incipient wetness impregnation method. The xCu/H-Sep and yFe-10Cu/H-Sep catalysts were characterized by means of XRD, BET, XRF, XPS, and H2-TPR techniques, and their catalytic activities were evaluated for the SCR of NO with propylene. XPS and XRD results indicate that there was the co-presence of Cu+-Cu2+ and Fe2+-Fe3+ over the surfaces of yFe-10Cu/H-Sep catalysts, and there was a strong interaction between Cu, Fe and sepiolite. High promotional effect of iron additive on the catalytic performance of Cu/H-Sep catalyst were found in C3H6-SCR of NO reaction. The highest activity of 65% NO conversion was obtained over 15Fe-10Cu/H-Sep catalyst at 280 oC under the condition of 1000 ppm NO, 1000 ppm C3H6, and 5% O2. The high catalytic activity of 15Fe-10Cu/H-Sep catalyst for NO reduction was due to its high reducibility to activate C3H6 to selectively reduce NO in the presence of excess O2. The high dispersion of copper oxides and strong metal-support interaction over 15Fe-10Cu/H-Sep catalyst also improve its catalytic performance.


2021 ◽  
Author(s):  
Liang Wei ◽  
Jian Chen ◽  
Shuai Lyu ◽  
Chengchao Liu ◽  
Yanxi Zhao ◽  
...  

The delicate balance between dispersion and reduction of the Co-based Fischer–Tropsch synthesis catalyst is the golden key to enhancing catalytic performance, which highly depends on an optimized metal–support interaction. In...


Nanoscale ◽  
2020 ◽  
Vol 12 (27) ◽  
pp. 14825-14830
Author(s):  
Kai-Qiang Jing ◽  
Yu-Qing Fu ◽  
Zhi-Qiao Wang ◽  
Zhe-Ning Chen ◽  
Hong-Zi Tan ◽  
...  

Zn2+-Modified MgAl-LDH with ultra-low Pd cluster loading was synthesized. The higher adsorption energy and strong covalent metal–support interaction via forming Pd–Zn bonds over Pd/ZnMgAl-LDH account for the robust catalytic performance.


Catalysts ◽  
2018 ◽  
Vol 8 (7) ◽  
pp. 285 ◽  
Author(s):  
M. Grabchenko ◽  
N. Mikheeva ◽  
G. Mamontov ◽  
M. Salaev ◽  
L. Liotta ◽  
...  

Nowadays catalytic technologies are widely used to purify indoor and outdoor air from harmful compounds. Recently, Ag–CeO2 composites have found various applications in catalysis due to distinctive physical-chemical properties and relatively low costs as compared to those based on other noble metals. Currently, metal–support interaction is considered the key factor that determines high catalytic performance of silver–ceria composites. Despite thorough investigations, several questions remain debating. Among such issues, there are (1) morphology and size effects of both Ag and CeO2 particles, including their defective structure, (2) chemical and charge state of silver, (3) charge transfer between silver and ceria, (4) role of oxygen vacancies, (5) reducibility of support and the catalyst on the basis thereof. In this review, we consider recent advances and trends on the role of silver–ceria interactions in catalytic performance of Ag/CeO2 composites in low-temperature CO oxidation, soot oxidation, and volatile organic compounds (VOCs) abatement. Promising photo- and electrocatalytic applications of Ag/CeO2 composites are also discussed.


RSC Advances ◽  
2015 ◽  
Vol 5 (37) ◽  
pp. 29040-29047 ◽  
Author(s):  
Bin Wang ◽  
Chao Wen ◽  
Yuanyuan Cui ◽  
Xi Chen ◽  
Yu Dong ◽  
...  

Crystal phase of titania support plays an important role in catalytic hydrogenation of dimethyl oxalate. Optimized catalytic performance was achieved for the Cu/P25 due to the intimate metal support interaction.


Nanomaterials ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 3149
Author(s):  
Songshan Zhu ◽  
Yunzhu Wang ◽  
Jichang Lu ◽  
Huihui Lu ◽  
Sufang He ◽  
...  

Steam reforming of glycerol to produce hydrogen is considered to be the very promising strategy to generate clean and renewable energy. The incipient-wetness impregnation method was used to load Ni on the reducible carrier TiO2 (P25). In the process of catalyst preparation, the interaction and electronic effect between metal Ni and support TiO2 were adjusted by changing the calcination temperature, and then the activity and hydrogen production of glycerol steam reforming reaction (GSR) was explored. A series of modern characterizations including XRD, UV-vis DRS, BET, XPS, NH3-TPD, H2-TPR, TG, and Raman have been applied to systematically characterize the catalysts. The characterization results showed that the calcination temperature can contribute to varying degrees of influences on the acidity and basicity of the Ni/TiO2 catalyst, the specific surface area, together with the interaction force between Ni and the support. When the Ni/TiO2 catalyst was calcined at 600 °C, the Ni species can be produced in the form of granular NiTiO3 spinel. Consequently, due to the moderate metal–support interaction and electronic activity formed between the Ni species and the reducible support TiO2 in the NiO/Ti-600C catalyst, the granular NiTiO3 spinel can be reduced to a smaller Ni0 at a lower temperature, and thus to exhibit the best catalytic performance.


RSC Advances ◽  
2016 ◽  
Vol 6 (38) ◽  
pp. 32290-32297 ◽  
Author(s):  
Cun-Zhi Li ◽  
Zhen-Bo Wang ◽  
Xu-Lei Sui ◽  
Li-Mei Zhang ◽  
Da-Ming Gu

A novel graphitic-C3N4 quantum dot modified carbon nanotube composite supported PtRu catalyst is prepared by π–π stacking. The enhanced catalytic performance of the catalyst is due to the better dispersion of PtRu NPs and the strong metal–support interaction (SMSI).


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