Surface Analysis of Cu/ZnO Catalysts for Methanol Synthesis - a Study on Nitrous Oxide Chemisorption and DRIFT Spectroscopy PDF Download
Are you looking for read ebook online? Search for your book and save it on your Kindle device, PC, phones or tablets. Download Surface Analysis of Cu/ZnO Catalysts for Methanol Synthesis - a Study on Nitrous Oxide Chemisorption and DRIFT Spectroscopy PDF full book. Access full book title Surface Analysis of Cu/ZnO Catalysts for Methanol Synthesis - a Study on Nitrous Oxide Chemisorption and DRIFT Spectroscopy by Samuel M. Fehr. Download full books in PDF and EPUB format.
Author: Samuel M. Fehr
Publisher:
ISBN:
Category :
Languages : en
Pages :
Get Book Here
Book Description
Author: Samuel M. Fehr
Publisher:
ISBN:
Category :
Languages : en
Pages :
Get Book Here
Book Description
Author: Samuel M. Fehr
Publisher:
ISBN:
Category :
Languages : en
Pages : 0
Get Book Here
Book Description
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 12
Get Book Here
Book Description
The adsorption and deactivation characteristics of coprecipitated Cu/ZnO-based catalysts were examined and correlated to their performance in methanol synthesis from CO2 hydrogenation. The addition of Ga2O3 and Y2O3 promoters is shown to increase the Cu surface area and CO2/H2 adsorption capacities of the catalysts and enhance methanol synthesis activity. Infrared studies showed that CO2 adsorbs spontaneously on these catalysts at room temperature as both monoand bi-dentate carbonate species. These weakly bound species desorb completely from the catalyst surface by 200 °C while other carbonate species persist up to 500 °C. Characterization using N2O decomposition, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and transmission electron microscopy (TEM) with energy-dispersive X-ray spectroscopy (EDX) analysis clearly indicated that Cu sintering is the main cause of catalyst deactivation. Ga and Y promotion improves the catalyst stability by suppressing the agglomeration of Cu and ZnO particles under pretreatment and reaction conditions.
Author: David Lloyd Roberts
Publisher:
ISBN:
Category :
Languages : en
Pages : 346
Get Book Here
Book Description
Author: Nan-Yu Topsøe
Publisher:
ISBN:
Category : Chemical engineering
Languages : en
Pages : 7
Get Book Here
Book Description
Author: Stefan Zander
Publisher: Sudwestdeutscher Verlag Fur Hochschulschriften AG
ISBN: 9783838150208
Category :
Languages : en
Pages : 132
Get Book Here
Book Description
Methanol is one of the most important industrial base chemicals and also a starting material for many organic syntheses. A steadily rising amount is used as fuel or fuel additive because methanol can serve as liquid hydrogen carrier. In the chemical industry, methanol is produced from synthesis gas over Cu/ZnO based catalysts. The catalyst is prepared by a multi-step synthesis (co-precipitation, calcination, reduction). Already in early stages of the preparation structural characteristics can provide indications for the resulting activity of the final catalyst. In order to investigate correlations between preparation parameters, microstructure and activity of Cu/ZnO based catalysts, the effects of the pH during co-precipitation and aging, use of MgO instead of ZnO and doping with Ga-ions were examined in the present work. Precursors, calcined and reduced samples were investigated with different methods (XRD, XRF, physisorption, TPR, RFC, UV-Vis spectroscopy, XAS, XPS, SEM, TEM) and selected samples were tested in methanol synthesis.
Author: Stephen Vincent Didziulis
Publisher:
ISBN:
Category :
Languages : en
Pages : 696
Get Book Here
Book Description
Author: P. Vesborg
Publisher:
ISBN:
Category :
Languages : en
Pages : 105
Get Book Here
Book Description
Author: Stefan Zander
Publisher:
ISBN:
Category :
Languages : en
Pages :
Get Book Here
Book Description
Author:
Publisher:
ISBN:
Category : Catalysts
Languages : en
Pages : 180
Get Book Here
Book Description
Several methods (sol-gel method, co-precipitation, homogeneous-precipitation) have been comparatively examined for the preparation of binary Cu/ZnO-based catalysts with Cu/Zn molar ratios in 70/30, 50/50 and 30/70 copper acetate (Cu(CH3COO)2H2O) and zinc acetate (Zn(CH3COO)2 2H2O) and ethanol were used as precursor for preparation of Cu/ZnO catalyst by sol-gel method. For co-precipitation method were prepared by the addition rate of a mixed copper nitrate (Cu(NO3)2) and zince nitrate (Zn(NO3)2) solution with a sodium carbonate (Na2CO3) solution. For homogeneous precipitation method were prepared by urea instead of Na2CO3 solution. All Cu/ZnO catalysts were applied for the catalytic production of hydrogen by steam reforming of methanol (SRM). Homogeneous precipitation method is preferable for this reaction. Then, study effect of calcinations conditions. Cu/ZnO catalysts are calcined by various atmospheres. Gases were used as atmosphere as follows: nitrogen, oxygen, air and hydrogen. Cu/ZnO catalyst was calcined by hydrogen, is the higher activity than the other atmospheres. Physical and chemical properties of Cu/ZnO catalyst were characterized by various techniques including X-ray diffraction (XRD), BET surface area, N2O chemisorption, Thermal gravimetric and differential thermal analysis (TG/DTA), Transmission electron microscopy (TEM), and Fourier transform infrared spectroscopy (FT-IR).
