Effect of calcination temperature on the structure and catalytic performance of 80Ni20CO/SiO2 catalyst for CO2 methanation

2017 ◽  
Author(s):  
S. A. Md Ali ◽  
K. H. K. Hamid ◽  
K. N. Ismail
Catalysts ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 354
Author(s):  
Khadijah H. Alharbi ◽  
Ali Alsalme ◽  
Ahmed Bader A. Aloumi ◽  
Mohammed Rafiq H. Siddiqui

Oxidation is an important organic transformation, and several catalysts have been reported for this conversion. In this study, we report the synthesis of mixed metal oxide CuxZnyO, which is prepared by a coprecipitation method by varying the molar ratio of Cu and Zn in the catalytic system. The prepared mixed metal oxide CuxZnyO was evaluated for catalytic performance for toluene oxidation. Various parameters of the catalytic evaluation were studied in order to ascertain the optimum condition for the best catalytic performance. The results indicate that aging time, calcination temperature, reaction temperature, and feed rate influence catalytic performance. It was found that the catalyst interfaces apparently enhanced catalytic activity for toluene oxidation. The XRD diffractograms reveal the crystalline nature of the mixed metal oxide formed and also confirm the coexistence of hexagonal and monoclinic crystalline phases. The catalyst prepared by aging for 4 h and calcined at 450 °C was found to be the best for the conversion of toluene to benzaldehyde while the reactor temperature was maintained at 250 °C with toluene fed into the reactor at 0.01 mL/min. The catalyst was active for about 13 h.


2008 ◽  
Vol 9 (10) ◽  
pp. 2059-2062 ◽  
Author(s):  
Ji Chul Jung ◽  
Howon Lee ◽  
Heesoo Kim ◽  
Sunyoung Park ◽  
Young-Min Chung ◽  
...  

2016 ◽  
Vol 333 ◽  
pp. 227-237 ◽  
Author(s):  
Jinghua Xu ◽  
Xiong Su ◽  
Hongmin Duan ◽  
Baolin Hou ◽  
Qingquan Lin ◽  
...  

2019 ◽  
Vol 19 (6) ◽  
pp. 3187-3196 ◽  
Author(s):  
Maria Mihet ◽  
Gabriela Blanita ◽  
Monica Dan ◽  
Lucian Barbu-Tudoran ◽  
Mihaela D Lazar

Pt/UiO-66 nanocomposites with platinum target concentration of 3 wt.% were prepared by 3 preparation methods, characterized and tested in the CO2 methanation process. Choice of the microporous UiO-66 metal-organic framework (Zr6O4(OH)4 with 1,4-benzene-dicarboxylate ligand) as catalytic support was motivated by the CO2 chemisorption capacity (proven by CO2-TPD profiles), large specific surface area (1477 m2/g) which favors a high dispersion of metal nanoparticles and good thermal stability. The preparation methods for the Pt/UiO-66 nanocomposites are: (1) wetimpregnation followed by reduction in H2 at 200 °C for 2 h; (2) wet-impregnation followed by reduction with an aqueous solution of NaBH4; and (3) “double-solvent” method, followed by reduction with NaBH4. The UiO-66 based nanocomposites were characterized by N2 adsorption–desorption (BET method), XRD, and SEM/TEM. The Pt/UiO-66 catalyst prepared by method 3 was chosen for catalytic testing due to its highest surface area, smallest platinum nanoparticles (PtNPs) size, the localization of PtNPs both on the grain’s internal and external surface and best thermal stability in the desired temperature range. Its capacity to adsorb and activate CO2 and H2 was evaluated in thermo-programmed desorption experiments (H2-TPD and CO2-TPD). Hydrogen is molecularly adsorbed, while CO2 is adsorbed both molecularly and dissociatively. The catalytic performance in the CO2 methanation process was evaluated by Temperature Programmed Reactions (TPRea, 2 °C/min, 30–350 °C), at atmospheric pressure. The best results were obtained at 350 °C, CO2:H2 molar ratio of 1:5.2 and GHSV ═ 1650 h−1. In these conditions CO2 conversion is almost 50% and CH4 selectivity is 36%, the rest of the converted CO2 being transformed in CO.


Author(s):  
Yue Teng ◽  
Ke Yao ◽  
Wenbin Song ◽  
Yongjun Sun ◽  
Haoliang Liu ◽  
...  

Cu-Mn-Ce@γ-Al2O3 was prepared by incipient wetness impregnation and used to catalyze ozonation in a coal chemical wastewater-biotreated effluent. The preparation factors that considerably affected the catalytic performance of Cu-Mn-Ce@γ-Al2O3, specifically metal oxide loading percentage, calcination temperature, and calcination time, were examined. The catalyst was characterized by scanning electron microscopy, energy dispersive spectrometry, X-ray diffraction, and Brunauer-Emmett-Teller analysis. The optimal catalytic ozonation operating parameters, such as ozone dosage, catalyst dosage, pH, and reaction time, were also investigated. Results showed that an optimized catalyst consisted of 17.0% CuO, 3.0% MnO2, and 2.0% CeO2 (wt.%). The optimal calcination temperature and calcination time were 600 °C and 5 h. The optimal catalytic ozonation operating parameters, including ozone dosage, catalyst dosage, pH, and reaction time, were 7, 80.0 mg/L, 20.0 mg/L, 7 and 50 min, respectively. The COD removal of biotreated effluent increased to 61% under these optimal operating conditions. Meanwhile, ozonation alone resulted in only 20% removal. This work proposes the use of easily available Cu-Mn-Ce@γ-Al2O3 catalyst and might drive the advancement of catalytic ozonation for chemical wastewater purification.


2016 ◽  
Vol 55 (16) ◽  
pp. 4451-4460 ◽  
Author(s):  
Salvatore Abate ◽  
Chalachew Mebrahtu ◽  
Emanuele Giglio ◽  
Fabio Deorsola ◽  
Samir Bensaid ◽  
...  

Catalysts ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 599 ◽  
Author(s):  
Le ◽  
Kim ◽  
Jeong ◽  
Park

In this study, unique core-shell aluminate spinel supports, Al@MAl2O4 (M = Zn, Mg, or Mn), were obtained by simple hydrothermal surface oxidation and were applied to the preparation of supported Ni catalysts for CO2 methanation. For comparison, CO methanation was also evaluated using the same catalysts. The prepared catalysts were characterized with a variety of techniques, including N2 physisorption, CO2 chemisorption, H2 chemisorption, temperature-programmed reduction with H2, temperature-programmed desorption of CO2, X-ray diffraction, high-resolution transmission electron microscopy, and in-situ diffuse reflectance infrared Fourier transform spectroscopy. The combination of supports with core-shell spinel structures and Ni doping with a deposition–precipitation method created outstanding catalytic performance of the Ni catalysts supported on Al@MgAl2O4 and Al@MnAl2O4 due to improved dispersion of Ni nanoparticles and creation of moderate basic sites with suitable strength. Good stability of Ni/Al@MnAl2O4 catalyst was also confirmed in the study.


2018 ◽  
Vol 43 (1) ◽  
pp. 239-250 ◽  
Author(s):  
Qing Liu ◽  
Shengjia Wang ◽  
Guoming Zhao ◽  
Hongyuan Yang ◽  
Meng Yuan ◽  
...  

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