Selective catalytic reduction of NO by ammonia on V2O5–SO42−/TiO2 catalysts prepared by the sol–gel method

The VO x -TiO 2 (VT-RC) and sulfated VO x -TiO 2 (VTS-RC) catalysts were prepared by rapid combustion method (RC) and evaluated by the one-step oxidation of methanol to dimethoxymethane (DMM). The results showed that the VT-RC and VTS-RC catalysts were consisted of nano-particles and exhibited pore structure. Compared with the coprecipitated VO x -TiO 2 (VT-CP) catalyst, the VT-RC catalyst showed more acidic sites and stronger reducibility. The addition of sulfate into VT catalyst further increased the number of acidic sites and had little effect on the reducibility. The catalytic test showed that the VT-RC catalyst exhibited high DMM selectivity (89.96% at 35% methanol conversion), which was further increased on VTS-RC catalyst (91.76% at 48% methanol conversion), and that was due to the larger number of acidic sites and stronger reducibility on these catalysts.

Section: Redox and Acidity Propertiessupporting

confidence: 94%

The One-Step Oxidation of Methanol to Dimethoxymethane over Nanostructure Vanadium-Based Catalysts

Guo

Jiang

et al. 2010

“…It is generally acknowledged that the band around 1,030 cm -1 is associated with V=O bridge of monomeric VO X [23][24][25], and the band around 920-940 cm -1 with V-O-V bridge of polymeric VO X species [26][27][28][29]. According to the previous studies [30,31], V=O band of monomeric VO X spices is advantage for the SCR reaction. The present result shows the broad peaks around 1,019 and 917 cm -1 that are attributed to V=O bridge monomeric and V-O-V band polymeric VO X species, respectively.…”

Section: Raman Spectramentioning

confidence: 92%

Phase structure of V2O5/TiO2 catalyst and catalytic behavior with removal of NO by ammonia

Zhang

et al. 2009

V 2 O 5 /TiO 2 catalyst with 3% (w/w) V loading has been prepared by sol-gel method. The characterization results of the catalyst structure and catalytic activity show that VO X state is strongly dependent on the calcination temperature. Little effect is found for phase structure of TiO 2 support on catalytic activity. High catalytic activity in wide temperature range (240-420°C) is observed for the catalysts calcinated at different temperatures at a space velocity of 50,000 h -1 . Space velocity and alkali metal oxides strongly influence the catalytic activity of the catalyst which was calcinated at 450°C, furthermore, the one has high tolerance to SO 2 in our test conditions.

“…Consequently, the catalysts show a good activity in the wider temperature range. It was reported [1] that, at about 450°C, the NO conversion of V 2 O 5 /TiO 2 catalyst with 1 wt% vanadia loading is greater than 90%. However, the present work identified a temperature of 360°C for NO conversion.…”

Section: Activity Tests For No Reduction By Nh3 Over V 2 O 5 /Tio 2 Cmentioning

confidence: 98%

“…and V 4? oxidation state [1,12]. According to calculating the area of XPS peak fitting, the ratio of V 5?…”

Section: Characterization Of Catalystsmentioning

confidence: 99%

“…Baraket [1] fabricated a sulfated TiO 2 (V 2 O 5 -SO 4 2-/TiO 2 ) catalyst with low vanadia loading (1 wt%), and found that the NO conversion exceeds 90% at temperature above 400°C. Djerad et al [2,3] studied the effects of vanadia and tungsten loadings on the physical and chemical properties of V 2 O 5 -WO 3 /TiO 2 catalysts and concluded that the vanadia content influences significantly the catalytic behavior.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Selective Catalytic Reduction of NO by Ammonia on V2O5/TiO2 Catalyst Prepared by Sol–Gel Method

Zhang

et al. 2009

V 2 O 5 /TiO 2 catalysts with various vanadia loadings were prepared using inorganic precursor of vanadium by sol-gel method, and characterized by XRF, XRD, BET, Raman spectra and XPS techniques. Results demonstrated that the catalyst with 6.17 wt% vanadia had a high activity in the temperature range from 180 to 450°C at a gas hourly space velocity of 10,000 h -1 and the activity was affected by increasing the space velocity at the temperature below 270°C. All the catalysts showed high activity in the different temperature range under tested conditions.