CO Adsorption Behavior of Cu/SiO2, Co/SiO2, and CuCo/SiO2 Catalysts Studied by in Situ DRIFTS

2012 ◽  
Vol 116 (14) ◽  
pp. 7931-7939 ◽  
Author(s):  
Miranda L. Smith ◽  
Nitin Kumar ◽  
James J. Spivey
Keyword(s):  
Co Adsorption ◽  
Adsorption Behavior ◽  
In Situ Drifts

In situ DRIFTS study of NOx adsorption behavior on Ba/CeO2 catalysts

2013 ◽  
Vol 31 (11) ◽  
pp. 1074-1080 ◽  
Author(s):  
Lei WANG ◽  
Rui RAN ◽  
Xiaodong WU ◽  
Min LI ◽  
Duan WENG
Keyword(s):  
Adsorption Behavior ◽  
In Situ Drifts ◽  
Nox Adsorption

Pd Nanoparticles Fabricated on Organic-Group Modified Silica and its Catalytic Performance for Acetylene Hydrogenation

2011 ◽  
Vol 233-235 ◽  
pp. 1884-1888
Author(s):  
Kang Jun Wang ◽  
Jing Wu ◽  
Ping Yu
Keyword(s):  
Sol Gel ◽  
Co Adsorption ◽  
Pd Nanoparticles ◽  
Catalytic Performance ◽  
Pd Catalyst ◽  
Modified Silica ◽  
In Situ Drifts ◽  
Organic Group ◽  
Sol Gel Process

Aminopropyl-functionalized silica (NH2-SiO2) was obtained via a sol-gel process using tetraethoxylsilicate (TEOS) and aminopropyltriethoxysilane (APTES). Aminopropyl group contained silica was further modified with formaldehyde to achieve a novel organic group modified silica, denoted as CH2O-SiO2. Using CH2O-SiO2 as support to prepare surported Pd catalyst (denoted as Pd/M-SiO2), small Pd nanoparticles (1-2 nm) were fabricated on CH2O-SiO2 surport. Hydrogenation of acetylene is used as probe reaction to evaluate the catalytic performance of Pd/M-SiO2. The results indicate that Pd/M-SiO2 exhibits unique catalytic property, which the selectivity of ethylene increases with the increase of acetylene conversion. In-situ DRIFTS spectra of CO adsorption show that the organic groups presented on the silica affect the electronic property of the very small Pd nanoparticles, which causes the change of reaction paths of hydrogenation of acetylene over Pd/M-SiO2 compared with traditional supported Pd catalyst.

In Situ FT-IR Study on the Effect of Cobalt Precursors on CO Adsorption Behavior

2010 ◽  
Vol 115 (4) ◽  
pp. 990-998 ◽  
Author(s):  
Nitin Kumar ◽  
K. Jothimurugesan ◽  
George G. Stanley ◽  
Viviane Schwartz ◽  
J. J. Spivey
Keyword(s):  
Co Adsorption ◽  
Adsorption Behavior ◽  
Ft Ir ◽  
Ir Study

A comparative study of CO adsorption and oxidation on Au/Fe2O3 catalysts by FT-IR and in situ DRIFTS spectroscopies

2006 ◽  
Vol 252 (1-2) ◽  
pp. 163-170 ◽  
Author(s):  
Goran Šmit ◽  
Neven Strukan ◽  
Menno W.J. Crajé ◽  
Károly Lázár
Keyword(s):  
Comparative Study ◽  
Co Adsorption ◽  
In Situ Drifts ◽  
Ft Ir

scholarly journals Insight into the Promoting Role of Er Modification on SO2 Resistance for NH3-SCR at Low Temperature over FeMn/TiO2 Catalysts

Catalysts ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 618
Author(s):  
Huan Du ◽  
Zhitao Han ◽  
Xitian Wu ◽  
Chenglong Li ◽  
Yu Gao ◽  
...  
Keyword(s):  
Low Temperature ◽  
Catalyst Surface ◽  
Impregnation Method ◽  
In Situ Drifts ◽  
Tio2 Catalyst ◽  
Nh3 Scr ◽  
Nh3 Adsorption ◽  
So2 Resistance ◽  
Fast Scr

Er-modified FeMn/TiO2 catalysts were prepared through the wet impregnation method, and their NH3-SCR activities were tested. The results showed that Er modification could obviously promote SO2 resistance of FeMn/TiO2 catalysts at a low temperature. The promoting effect and mechanism were explored in detail using various techniques, such as BET, XRD, H2-TPR, XPS, TG, and in-situ DRIFTS. The characterization results indicated that Er modification on FeMn/TiO2 catalysts could increase the Mn4+ concentration and surface chemisorbed labile oxygen ratio, which was favorable for NO oxidation to NO2, further accelerating low-temperature SCR activity through the “fast SCR” reaction. As fast SCR reaction could accelerate the consumption of adsorbed NH3 species, it would benefit to restrain the competitive adsorption of SO2 and limit the reaction between adsorbed SO2 and NH3 species. XPS results indicated that ammonium sulfates and Mn sulfates formed were found on Er-modified FeMn/TiO2 catalyst surface seemed much less than those on FeMn/TiO2 catalyst surface, suggested that Er modification was helpful for reducing the generation or deposition of sulfate salts on the catalyst surface. According to in-situ DRIFTS the results of, the presence of SO2 in feeding gas imposed a stronger impact on the NO adsorption than NH3 adsorption on Lewis acid sites of Er-modified FeMn/TiO2 catalysts, gradually making NH3-SCR reaction to proceed in E–R mechanism rather than L–H mechanism. DRIFTS.

scholarly journals Experimental and Theoretical Studies of Sonically Prepared Cu–Y, Cu–USY and Cu–ZSM-5 Catalysts for SCR deNOx

Catalysts ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 824
Author(s):  
Przemysław J. Jodłowski ◽  
Izabela Czekaj ◽  
Patrycja Stachurska ◽  
Łukasz Kuterasiński ◽  
Lucjan Chmielarz ◽  
...  
Keyword(s):  
Ion Exchange ◽  
Ultrasonic Irradiation ◽  
Active Phase ◽  
Spectroscopic Studies ◽  
In Situ Drifts ◽  
Ft Ir ◽  
Diffuse Reflectance Infrared ◽  
Experimental And Theoretical Studies

The objective of our study was to prepare Y-, USY- and ZSM-5-based catalysts by hydrothermal synthesis, followed by copper active-phase deposition by either conventional ion-exchange or ultrasonic irradiation. The resulting materials were characterized by XRD, BET, SEM, TEM, Raman, UV-Vis, monitoring ammonia and nitrogen oxide sorption by FT-IR and Diffuse Reflectance Infrared Fourier Transform Spectroscopy (DRIFTS). XRD data confirmed the purity and structure of the Y/USY or ZSM-5 zeolites. The nitrogen and ammonia sorption results indicated that the materials were highly porous and acidic. The metallic active phase was found in the form of cations in ion-exchanged zeolites and in the form of nanoparticle metal oxides in sonochemically prepared catalysts. The latter showed full activity and high stability in the SCR deNOx reaction. The faujasite-based catalysts were fully active at 200–400 °C, whereas the ZSM-5-based catalysts reached 100% activity at 400–500 °C. Our in situ DRIFTS experiments revealed that Cu–O(NO) and Cu–NH3 were intermediates, also indicating the role of Brønsted sites in the formation of NH4NO3. Furthermore, the results from our experimental in situ spectroscopic studies were compared with DFT models. Overall, our findings suggest two possible mechanisms for the deNOx reaction, depending on the method of catalyst preparation (i.e., conventional ion-exchange vs. ultrasonic irradiation).

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