Get Rid of the Shackle from Supports: Construct Recoverable Semi-Homogeneous Catalysts with Attapulgite

2021 ◽  
Author(s):  
Ruixiang Guo ◽  
Gang Wang ◽  
Wei Liu ◽  
Zibei Yao ◽  
Wei-Sheng Liu
Keyword(s):  
Catalytic Activity ◽  
Homogeneous Catalysts ◽  
Immobilized Catalyst ◽  
Novel Strategy ◽  
Adsorption Desorption

Traditionally, the immobilized catalyst sacrifices a part of catalytic activity for its recyclability. To reproduce the catalytic activity of active specie, we construct a novel strategy called "adsorption-desorption-adsorption". Since the...

VISIBLE LIGHT ACTIVE Cu2+/TiO2 NANOCATALYST FOR DEGRADATION OF DICHLORVOS

2012 ◽  
Vol 11 (05) ◽  
pp. 1250030 ◽  
Author(s):  
TESHOME ABDO SEGNE ◽  
SIVA RAO TIRUKKOVALLURI ◽  
SUBRAHMANYAM CHALLAPALLI
Keyword(s):  
Catalytic Activity ◽  
Visible Light ◽  
Photoelectron Spectroscopy ◽  
Diffuse Reflectance Spectroscopy ◽  
Sol Gel ◽  
Light Illumination ◽  
X Ray ◽  
Photo Catalytic Activity ◽  
Visible Light Active ◽  
Adsorption Desorption

The advantage of doping of TiO2 with copper has been utilized for enhanced degradation of pesticide under visible light irradiation. The sol–gel method has been undertaken for the synthesis of copper-doped TiO2 by varying the dopant loadings from 0.25 wt.% to 1.0 wt.% of Cu2+ . The doped samples were characterized by UV-Visible Diffuse Reflectance Spectroscopy (DRS), N2 adsorption–desorption (BET), X-ray Diffraction (XRD), X-ray Photoelectron Spectroscopy (XPS), Scanning Electron Microscopy (SEM), and Energy Dispersive Spectrometry (EDS). The photocatalytic activity of the catalyst was tested by degradation of dichlorvos under visible light illumination. The results found that 0.75 wt.% of Cu2+ doped nanocatalysts have better photo catalytic activity than the rest of percentages doped, undoped TiO2 and Degussa P25. The reduction of band gap was estimated and the influence of the process parameters on photo catalytic activity of the catalyst has been explained.

Catalytic Activity of Dehydrogenation of Methanol to MF over Cu/MCM-41 and Cu-ZnO/MCM-41 Prepared by Impregnation and Grinding

2011 ◽  
Vol 396-398 ◽  
pp. 730-733
Author(s):  
Guo Ru Li ◽  
Gong Li ◽  
Shu Xi Zhou ◽  
Hui Juan Tong
Keyword(s):  
Catalytic Activity ◽  
Atmospheric Pressure ◽  
Molecular Sieves ◽  
Conversion Rate ◽  
Methyl Formate ◽  
Methanol Conversion ◽  
N2 Adsorption ◽  
Flow Microreactor ◽  
Adsorption Desorption ◽  
Mcm 41

Abstract. Using MCM-41 molecular sieves as the support, Cu-ZnO/MCM-41 and Cu/MCM-41 catalysts were prepared by impregnation and grinding. The catalysts were characterized by XRD, N2 adsorption-desorption and TPR methods. The catalytic activity of the dehydrogenation of methanol to methyl formate (MF) was evaluated using the flow microreactor under atmospheric pressure. According to the results, the catalyst prepared by impregnation had a better selectivity for the MF, but a lower methanol conversion rate. However, the product's selectivity could be improved by adding ZnO additive while the methanol conversion rate was reduced. For Cu/MCM-41 prepared by impregnation and grinding, the methanol conversion rate was 20.18% and 24.13% respectively at 250°C and the MF selectivity was 73.75% and 67.35% respectively. Likewise for Cu-ZnO/MCM-41 prepared by impregnation and grinding, the methanol conversion rate was 15.28% and 18.83% respectively at 250°C and the MF selectivity was 81.31% and 75.32% respectively.

scholarly journals A novel strategy for stabilization of sub-nanometric Pd colloids on kryptofix functionalized MCM-41: nanoengineered material for Stille coupling transformation

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Hassan Alamgholiloo ◽  
Nader Noroozi Pesyan ◽  
Sadegh Rostamnia
Keyword(s):  
Catalytic Activity ◽  
Large Scale ◽  
Coupling Reaction ◽  
Vital Role ◽  
Metal Particles ◽  
Stille Coupling ◽  
Coupling Transformation ◽  
Novel Strategy ◽  
Average Size ◽  
Mcm 41

AbstractThe stabilization of sub-nanometric metal particles (< 1 nm) with suitable distribution remained challenging in the catalytic arena. Herein, an intelligent strategy was described to anchoring and stabilizing sub-nanometric Pd colloids with an average size of 0.88 nm onto Kryptofix 23 functionalized MCM-41. Then, the catalytic activity of Pd@Kryf/MCM-41 was developed in Stille coupling reaction with a turnover frequency (TOF) value of 247 h−1. The findings demonstrate that porous MCM-41 structure and high-affinity Kryptofix 23 ligand toward adsorption of Pd colloids has a vital role in stabilizing the sub-nanometric particles and subsequent catalytic activity. Overall, these results suggest that Pd@Kryf/MCM-41 is a greener, more suitable option for large-scale applications and provides new insights into the stabilization of sub-nanometric metal particles.

scholarly journals Oxidative Desulfurization of Dibenzothiophene Using Dawson Type Heteropoly Compounds/Tantalum as Catalyst

2018 ◽  
Vol 16 (1) ◽  
pp. 105 ◽  
Author(s):  
Risfidian Mohadi ◽  
Lusi Teresia ◽  
Najma Annuria Fithri ◽  
Aldes Lesbani ◽  
Nurlisa Hidayati
Keyword(s):  
Catalytic Activity ◽  
Vibration Spectrum ◽  
Oxidative Desulfurization ◽  
Heteropoly Compounds ◽  
Atmospheric Conditions ◽  
N2 Adsorption ◽  
Fresh Catalyst ◽  
Wet Impregnation ◽  
Percent Conversion ◽  
Adsorption Desorption

Catalyst (NH4)6[b-P2W18O62]/Ta has been synthesized by simple wet impregnation at 30-40 °C under atmospheric conditions using Dawson type polyoxometalate (NH4)6[b-P2W18O62] and tantalum. The catalyst was characterized by FTIR spectrophotometer, XRD, SEM, and N2 adsorption desorption methods. FTIR spectrum of (NH4)6[b-P2W18O62]/Ta showed that Dawson type polyoxometalate (NH4)6[b-P2W18O62] and Ta was successfully impregnated which was indicated by vibration spectrum at wavenumber of 900-1100 cm-1 for polyoxometalate and 550 cm-1 for Ta. The surface area of the (NH4)6[b-P2W18O62]/Ta after impregnation was higher than (NH4)6[b-P2W18O62]•nH2O and its morphology was found to be uniform. The catalytic activity of (NH4)6[b-P2W18O62]/Ta toward desulfurization of dibenzothiophene was three times higher than the original catalyst of (NH4)6[b-P2W18O62]•nH2O without impregnation. The catalytic regeneration test of catalyst (NH4)6[b-P2W18O62]/Ta showed that the catalytic activity for first regeneration of catalyst has similar catalytic activity with the fresh catalyst without loss of catalytic activity indicated by almost similar percent conversion.

scholarly journals Synthesis of porous LaFeO3 prepared by nanocasting method for photo-Fenton degradation of oily-containing wastewater

2021 ◽  
Vol 11 (1) ◽  
pp. xx-xx
Author(s):  
Nga Phan To ◽  
Lien Nguyen Hong ◽  
Tuyen Le Van ◽  
Nhan Phan Chi ◽  
Huyen Phan Thanh
Keyword(s):  
Electron Microscopy ◽  
Catalytic Activity ◽  
Visible Light ◽  
Diffuse Reflectance Spectroscopy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Catalytic Activities ◽  
Transmission Electron ◽  
Visible Light Driven ◽  
Adsorption Desorption

Porous LaFeO3 were synthesised by nanocasting method using mesoporous silica (SBA-15) as a hard template and used as a visible-light-driven photocatalyst. The as-synthesised LaFeO3 photocatalyst were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray Diffraction (XRD), N2 adsorption-desorption, and Ultraviolet–Visible Diffuse Reflectance Spectroscopy (UV-vis DRS). The photo-Fenton catalytic activities of porous LaFeO3 were investigated for the degradation of oily-containing wastewater. The results showed that porous LaFeO3 had better photo-Fenton catalytic activity under visilbe light irradiation than pure LaFeO3. The remarkable improvement photo-Fenton catalytic activity of porous LaFeO3 material could be attributed to the synergistic effect of adsorption and visible light photo-Fenton processes thanks to its porous structure.

Single Pt atom supported on penta-graphene as an efficient catalyst for CO oxidation

2019 ◽  
Vol 21 (23) ◽  
pp. 12201-12208 ◽  
Author(s):  
Ranganathan Krishnan ◽  
Shiuan-Yau Wu ◽  
Hsin-Tsung Chen
Keyword(s):  
Catalytic Activity ◽  
Co Oxidation ◽  
Systematic Study ◽  
First Principles ◽  
Single Atom ◽  
First Principles Calculations ◽  
Efficient Catalyst ◽  
Spin Polarized ◽  
Novel Strategy

We performed a systematic study of CO oxidation on a single Pt atom supported on penta-graphene (Pt/PG) by utilizing spin-polarized first-principles calculations. The results manifested that Pt/PG, as a single-atom catalyst, exhibited excellent catalytic activity toward CO oxidation and provided a novel strategy for the design of single-atom catalysts based on penta-graphene.

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