Low-Temperature Direct Dehydrogenation of Propane over Binary Oxide Catalysts: Insights into Geometric Effects and Active Sites

The selective catalytic reduction of NOx (deNOx) at temperatures less than or at 200 °C was investigated while using C2H4 as the reductant and mixed oxides of Fe and Mn supported on activated carbon; their activity was compared to that of MnOx and FeOx separately supported on activated carbon. The bimetallic oxide compositions maintained high NO conversion of greater than 80–98% for periods that were three times greater than those of the supported monometallic oxides. To examine potential reasons for the significant increases in activity maintenance, and subsequent deactivation, the catalysts were examined by using bulk and surface sensitive analytical techniques before and after catalyst testing. No significant changes in Brunauer-Emmett-Teller (BET) surface areas or porosities were observed between freshly-prepared and tested catalysts whereas segregation of FeOx and MnOx species was readily observed in the mono-oxide catalysts after reaction testing that was not detected in the mixed oxide catalysts. Furthermore, x-ray diffraction and Raman spectroscopy data detected cubic Fe3Mn3O8 in both the freshly-prepared and reaction-tested mixed oxide catalysts that were more crystalline after testing. The presence of this compound, which is known to stabilize multivalent Fe species and to enhance oxygen transfer reactions, may be the reason for the high and relatively stable NO conversion activity, and its increased crystallinity during longer-term testing may also decrease surface availability of the active sites responsible for NO conversion. These results point to a potential of further enhancing catalyst stability and activity for low temperature deNOx that is applicable to advanced SCR processing with lower costs and less deleterious side effects to processing equipment.

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Iron doped effects on active sites formation over activated carbon supported Mn-Ce oxide catalysts for low-temperature SCR of NO

Chemical Engineering Journal ◽

10.1016/j.cej.2019.122398 ◽

2020 ◽

Vol 379 ◽

pp. 122398 ◽

Cited By ~ 18

Author(s):

Jie Yang ◽

Shan Ren ◽

Tianshi Zhang ◽

Zenghui Su ◽

Hongming Long ◽

...

Keyword(s):

Activated Carbon ◽

Low Temperature ◽

Active Sites ◽

Oxide Catalysts ◽

Scr Of No ◽

Iron Doped ◽

Low Temperature Scr

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Cover Picture: Rational Low-Temperature Synthesis of Ultrasmall Nanocrystalline Manganese Binary Oxide Catalysts under Controlled Metal Cation Hydration in Organic Media (ChemNanoMat 4/2016)

ChemNanoMat ◽

10.1002/cnma.201600114 ◽

2016 ◽

Vol 2 (4) ◽

pp. 243-243

Author(s):

Yumi Miyamoto ◽

Yoshiyuki Kuroda ◽

Tsubasa Uematsu ◽

Hiroyuki Oshikawa ◽

Naoya Shibata ◽

...

Keyword(s):

Low Temperature ◽

Metal Cation ◽

Binary Oxide ◽

Oxide Catalysts ◽

Organic Media ◽

Low Temperature Synthesis ◽

Temperature Synthesis ◽

Cation Hydration

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Novel Co– or Ni–Mn binary oxide catalysts with hydroxyl groups for NH3–SCR of NOx at low temperature

Applied Surface Science ◽

10.1016/j.apsusc.2018.02.151 ◽

2018 ◽

Vol 443 ◽

pp. 103-113 ◽

Cited By ~ 47

Author(s):

Fengyu Gao ◽

Xiaolong Tang ◽

Honghong Yi ◽

Shunzheng Zhao ◽

Jiangen Wang ◽

...

Keyword(s):

Low Temperature ◽

Binary Oxide ◽

Oxide Catalysts ◽

Hydroxyl Groups ◽

Nh3 Scr ◽

Scr Of Nox

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Physicochemical and Catalytic Properties of Spinels Formed by Solid-Solid Interaction Between Fe2O3and V2O5

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19961131 ◽

1996 ◽

Vol 61 (8) ◽

pp. 1131-1140 ◽

Cited By ~ 3

Author(s):

Abd El-Aziz Ahmed Said

Keyword(s):

Vanadium Oxide ◽

Active Sites ◽

Catalyst Surface ◽

Catalytic Properties ◽

Flow System ◽

Oxide Catalysts ◽

X Ray Diffraction ◽

Selective Catalyst ◽

X Ray ◽

Solid Catalysts

Vanadium oxide catalysts doped or mixed with 1-50 mole % Fe3+ ions were prepared. The structure of the original samples and those calcined from 200 up to 500 °C were characterized by TG, DTA, IR and X-ray diffraction. The SBET values and texture of the solid catalysts were investigated. The catalytic dehydration-dehydrogenation of isopropanol was carried out at 200 °C using a flow system. The results obtained showed an observable decrease in the activity of V2O5 on the addition of Fe3+ ions. Moreover, Fe2V4O13 is the more active and selective catalyst than FeVO4 spinels. The results were correlated with the active sites created on the catalyst surface.

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