scholarly journals Synthesis, characterisation and catalytic performance of Cu- and Co-modified Fe-Al co-precipitated catalysts for the steam reforming of ethanol

2014 ◽  
Vol 16 (6) ◽  
pp. 1111-1120
Keyword(s):  
Specific Surface ◽  
Steam Reforming ◽  
Catalytic Performance ◽  
Precipitation Method ◽  
Partial Substitution ◽  
Iron Species ◽  
Surface Areas ◽  
Steam Reforming Of Ethanol ◽  
And Performance ◽  
And Shifts

<p>This paper reports the synthesis and the investigation of the properties and performance of Fe-Al catalysts modified with Cu or Co for the steam reforming of ethanol. The materials were prepared by the precipitation method with different Fe/Al ratios. The samples were characterised by the S<sub>BET</sub>, TG/DTG, XRD, H<sub>2</sub>-TPR and TPO/DTA analyses. The increase in the Fe/Al ratio leads to a decrease in the specific surface area and shifts the reduction peaks towards higher temperatures. The partial substitution of Fe by Co or Cu modifies the structure of the materials because higher specific surface areas and crystallites of iron oxides with smaller sizes are formed. The promotion also improves the reducibility of the iron species. These changes provide higher activity and selectivity towards H<sub>2</sub> and CO for the modified samples and for the samples with lower Fe/Al ratio. The Co-containing catalyst showed the best performance because this sample exhibited the highest conversions and selectivity towards both H<sub>2</sub> and CO and the lowest formation of coke according to the TPO analysis.</p>

scholarly journals Thermal Modification Effect on Supported Cu-Based Activated Carbon Catalyst in Hydrogenolysis of Glycerol

Materials ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 603 ◽  
Author(s):  
Juan Seguel ◽  
Rafael García ◽  
Ricardo José Chimentão ◽  
José Luis García-Fierro ◽  
I. Tyrone Ghampson ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Specific Surface ◽  
Hydrogen Adsorption ◽  
Carbon Support ◽  
Catalytic Performance ◽  
Homogeneous Distribution ◽  
Surface Groups ◽  
Carbon Supports ◽  
Surface Areas ◽  
Oxygen Surface

Glycerol hydrogenolysis to 1,2-propanediol (1,2-PDO) was performed over activated carbon supported copper-based catalysts. The catalysts were prepared by impregnation using a pristine carbon support and thermally-treated carbon supports (450, 600, 750, and 1000 °C). The final hydrogen adsorption capacity, porous structure, and total acidity of the catalysts were found to be important descriptors to understand catalytic performance. Oxygen surface groups on the support controlled copper dispersion by modifying acidic and adsorption properties. The amount of oxygen species of thermally modified carbon supports was also found to be a function of its specific surface area. Carbon supports with high specific surface areas contained large amount of oxygen surface species, inducing homogeneous distribution of Cu species on the carbon support during impregnation. The oxygen surface groups likely acted as anchorage centers, whereby the more stable oxygen surface groups after the reduction treatment produced an increase in the interaction of the copper species with the carbon support, and determined catalytic performances.

scholarly journals Synthesis of DME by CO2 hydrogenation over La2O3-modified CuO-ZnO-ZrO2/HZSM-5 catalysts

2017 ◽  
Vol 23 (1) ◽  
pp. 49-56 ◽  
Author(s):  
Yajing Zhang ◽  
Yu Zhang ◽  
Fu Ding ◽  
Kangjun Wang ◽  
Wang Xiaolei ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Direct Synthesis ◽  
Catalytic Performance ◽  
Co2 Hydrogenation ◽  
Precipitation Method ◽  
X Ray ◽  
Temperature Programmed ◽  
And Performance ◽  
Co Precipitation ◽  
Adsorption Desorption

A series of La2O3-modified CuO-ZnO-ZrO2/HZSM-5 catalysts were prepared by an oxalate co-precipitation method. The catalysts were fully characterized by X-ray diffraction (XRD), N2 adsorption-desorption, hydrogen temperature pro-grammed reduction (H2-TPR), ammonia temperature programmed desorption (NH3-TPD), and X-ray photoelectron spectroscopy (XPS) techniques. The effect of the La2O3 content on the structure and performance of the catalysts was thoroughly investigated. The catalysts were evaluated for the direct synthesis of dimethyl ether (DME) from CO2 hydrogenation. The results displayed that La2O3 addition enhanced catalytic performance, and the maximal CO2 conversion (34.3%) and DME selectivity (57.3%) were obtained over the catalyst with 1% La2O3, which due to the smaller size of Cu species and a larger ratio of Cu+/Cu.

Effects of Ceria Morphology on Catalytic Performance of Ni/CeO2 Catalysts for Low Temperature Steam Reforming of Ethanol

2015 ◽  
Vol 58 (4-6) ◽  
pp. 281-294 ◽  
Author(s):  
Tamara Siqueira Moraes ◽  
Raimundo Crisostomo Rabelo Neto ◽  
Mauro Celso Ribeiro ◽  
Lisiane Veiga Mattos ◽  
Marios Kourtelesis ◽  
...  
Keyword(s):  
Low Temperature ◽  
Steam Reforming ◽  
Catalytic Performance ◽  
Steam Reforming Of Ethanol

Influence of the component interaction over Cu/ZrO2 catalysts induced with fractionated precipitation method on the catalytic performance for methanol steam reforming

RSC Advances ◽  
2016 ◽  
Vol 6 (36) ◽  
pp. 30176-30183 ◽  
Author(s):  
Jiajia Zhou ◽  
Ye Zhang ◽  
Guisheng Wu ◽  
Dongsen Mao ◽  
Guanzhong Lu
Keyword(s):  
Steam Reforming ◽  
Catalytic Performance ◽  
Precipitation Method ◽  
Methanol Steam Reforming ◽  
Steam Reforming Of Methanol ◽  
Component Interaction ◽  
Production Of Hydrogen ◽  
Composition Ratios

A series of binary Cu/ZrO2 catalysts by choosing different composition ratios and different precipitation sequences have been prepared for the production of hydrogen by steam reforming of methanol (SRM).

Study on the Cu-Ni/Y2O3-ZrO2 Catalytic Performance in Ethanol Steam Reforming

2012 ◽  
Vol 512-515 ◽  
pp. 2257-2261 ◽  
Author(s):  
Hong Da Wu ◽  
Ying Gui Jia ◽  
Yu Yin ◽  
Lue Zhao
Keyword(s):  
Steam Reforming ◽  
Conversion Rate ◽  
Carbon Deposition ◽  
Catalytic Performance ◽  
Precipitation Method ◽  
Ethanol Conversion ◽  
Ethanol Steam Reforming ◽  
Impregnation Method ◽  
Catalyst Composition ◽  
Ethanol Steam

Y2O3-ZrO2 support was prepared by two-step precipitation method with ammonia and oxalic acid. A series of Cu-Ni/Y2O3-ZrO2 catalysts were prepared by impregnation method. The catalysts were investigated and then characterized by XRD and SEM results. The activity of catalysts in ethanol steam reforming was studied. The effects of the catalyst composition on the ethanol conversion rate were discussed and the catalysts inactivation phenomenon under the temperature ranging from 673K to 723K was then analyzed. The results show that 1Cu9Ni/1Y9Zr catalyst has higher activity in ethanol steam reforming, over which ethanol conversion rate is higher than 98% under the situation of 623K, while the inactivation of catalysts with Cu/Ni>3/7 at 673K~723K was caused by carbon deposition .

scholarly journals Removal efficiency and mechanism of bio-treated coking wastewater by catalytic ozonation using MnO2 modified with anionic precursors

2020 ◽  
Vol 26 (5) ◽  
pp. 200394-0
Author(s):  
Jie Zhang ◽  
Ben Dong ◽  
Ding Ding ◽  
Shilong He ◽  
Sijie Ge
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Catalytic Performance ◽  
Catalytic Ozonation ◽  
Relative Content ◽  
Precipitation Method ◽  
Coking Wastewater ◽  
Physiochemical Properties ◽  
Removal Efficiencies

In this paper, MnO<sub>2</sub> catalyst were firstly prepared and modified by four kinds of anionic precursors (i.e., NO<sub>3</sub><sup>-</sup>, AC<sup>-</sup>, SO<sub>4</sub><sup>2-</sup> and Cl<sup>-</sup>) through redox precipitation method. After that, bio-treated coking wastewater (BTCW) was prepared and employed as targeted pollutants to investigate the catalytic ozonation performance of prepared-MnO<sub>2</sub> catalyst was investigated and characterized by the removal efficiencies and mechanism of the prepared bio-treated coking wastewater (BTCW), which was employed as the targeted pollutants. Specifically, the effects of specific surface area, crystal structure, valence state of Mn element and lattice oxygen content on catalytic activity of MnO<sub>2</sub> materials were characterized by BET, XRD and XPS, respectively. Results showed that COD of BTCW could be removed 47.39% under MnO<sub>2</sub>-NO<sub>3</sub><sup>-</sup> catalyst with 2 h reaction time, which was much higher than that of MnO<sub>2</sub>-AC<sup>-</sup> (3.94%), MnO<sub>2</sub>-SO<sub>4</sub><sup>2-</sup> (12.42%), MnO<sub>2</sub>-Cl<sup>-</sup> (12.94%) and pure O<sub>3</sub> without catalyst (21.51%), respectively. So, MnO<sub>2</sub>-NO<sub>3</sub><sup>-</sup> presented the highest catalytic performance among these catalysts. The reason may be attributed to a series of better physiochemical properties including the smaller average grain, the larger specific surface area and active groups, more crystal defect and oxygen vacancy, higher relative content of Mn<sup>3+</sup> and adsorbed oxygen (O<sub>ads</sub>) than that of another three catalysts.

Effect of Different Silicate Supports on the Catalytic Performance of MoVTeO Mixed Oxides in Partial Oxidation of Isobutane

2014 ◽  
Vol 12 (1) ◽  
pp. 623-628
Author(s):  
Jing Hu ◽  
Zhifang Li ◽  
Xiaoyuan Yang ◽  
Wenli Ding ◽  
Jingqi Guan
Keyword(s):  
Catalytic Activity ◽  
Specific Surface ◽  
Surface Area ◽  
Partial Oxidation ◽  
Mixed Oxides ◽  
Supported Catalysts ◽  
Catalytic Performance ◽  
Surface Areas ◽  
Specific Surface Areas ◽  
Mcm 41

Abstract A series of 5% MoV0.3Te0.25 supported on different silicates (i.e. SiO2, HMS, MCM-41, and MCM-48) have been prepared, characterized, and tested as catalysts in the partial oxidation of isobutane to methacrolein. Characterization results showed that the supports almost kept intact structures after supporting 5 wt.% MoV0.3Te0.25 and the supported catalysts had large specific surface areas. Catalytic tests showed that the specific surface area played a key role in the catalytic activity for the supported catalysts.

Role of Structural Deficiency of Nanoscaled Perovskites Prepared by Reactive Grinding on the Catalytic Purification of Exhaust Pollutants

2009 ◽  
Vol 7 (1) ◽  
Author(s):  
Runduo Zhang ◽  
Wei Yang ◽  
Jun Xue ◽  
Biaohua Chen
Keyword(s):  
Specific Surface ◽  
No Reduction ◽  
Soot Oxidation ◽  
Catalytic Performance ◽  
Surface Areas ◽  
No Reduction By Co ◽  
Cation Deficiency ◽  
Lanthanum Manganites ◽  
Calcination Step ◽  
Reactive Grinding

It is well known that the catalytic characteristics of perovskites for various redox reactions depend primarily on the preparation procedure. The conventional method for perovskite preparation, the so-called "ceramic method," involves a calcination step with a temperature of at least 800 oC, resulting in large grain size and low specific surface area (usually several m2/g). Recently, a new method for perovskite preparation designated as reactive grinding has been proposed by our group, generating a large variety of perovskites at room temperature with extraordinarily high specific surface areas on the order of 100 m2/g when grinding additives are used. Additionally, this novel technology is favorable to yield perovskites with an abundant deficiency structure simultaneously with a nanosized crystallite domain.Series of La(Co, Mn)1-x(Cu)xO3 perovskites were prepared by reactive grinding and characterized by XRD, O2-TPD, and H2-TPR showing anion deficiency (O2 vacancy) in lanthanum cobaltites and cation deficiency (O2 excess) in lanthanum manganites. These samples were thereafter used for catalytic purification of NO, CO and soot pollutants coming from an automobile. For NO reduction by CO, a better catalytic performance was found over LaCoO3 compared to LaMnO3. The deNOx activity of LaCoO3 can be considerably improved via 20% Cu substitution, leading to a 97% N2 yield and nearly complete CO conversion at 450 oC. This improvement was ascribed to the ease of generation of anion deficiencies after Cu incorporation, which plays a crucial role in NO adsorption and dissociation. A mechanism was proposed with dissociation of chemisorbed NO upon oxygen vacancies forming N2 and/or N2O, and oxidized perovskite surface, with continuous reduction by CO with the production of CO2. For soot combustion, the better activity was observed again in the case of LaCoO3 with respect to LaMnO3. A mechanism was proposed with an attack of soot by O- species which immigrates from the perovskite surface. Cation deficiency of lanthanum manganites associates with overstoichiometric oxygen from the perovskite lattice, which can be only utilized for an oxidation process but less active compared to molecular oxygen formed upon anion vacancies. In summary, the anion deficiency of perovskite-typed oxides seems to make more contribution for both NO reduction and soot oxidation in comparison with cation deficiency.

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