CO_(2)reformation of methane(CRM)and CO_(2)methanation are two interconnected processes with significant implications for greenhouse gas reduction and sustainable energy production for industrial purposes.While Nibase...CO_(2)reformation of methane(CRM)and CO_(2)methanation are two interconnected processes with significant implications for greenhouse gas reduction and sustainable energy production for industrial purposes.While Nibased catalysis suffers from poor stability due to coke formation or sintering,we report a super stable remedy.The active sites of mesoporous MgO were loaded using wet impregnation.The incorporation of Ni and promoters altered the physical features of the catalysts.Sm–Ni/MgO showed the smallest crystallite size,specific surface area,and pore volume.The Sm–Ni/MgO catalyst was selected as the most suitable candidate for CRM,with 82%CH4 and H2/CO ratio of approximately 100%and also for CO_(2)methanation with the conversion of carbon dioxide(82%)and the selectivity toward methane reaches 100%at temperatures above 300ᵒC.Furthermore,the Sm–Ni/MgO catalyst was stable for 900 min of continuous reaction,without significant carbon deposition.This stability was largely due to the high oxygen mobility on the catalyst surface in the presence of Sm.Overall,we demonstrated the efficacy of using promoted Ni catalysts supported by mesoporous magnesia for the improved reformation of greenhouse gases.展开更多
In this study, mesoporous silica/iron oxide nanocomposite(MCM-FeO) was synthesized via hydrothermal technique. The chemical synthesis of MCM-FeOnanocomposite was achieved at 18 h. The effect of concentration of tetrae...In this study, mesoporous silica/iron oxide nanocomposite(MCM-FeO) was synthesized via hydrothermal technique. The chemical synthesis of MCM-FeOnanocomposite was achieved at 18 h. The effect of concentration of tetraethylorthosilicate(TEOS) on nanocomposites properties was studied during synthesis process. For this purpose, 0.5, 1.5, 2.5, 3.5, and 4.5 ml tetraethylorthosilicate(TEOS) were selected, respectively. The textural properties and microstructure of the nanocomposites were characterized by X-ray diffraction(XRD), Fourier transform infrared spectroscopy(FTIR), field emission scanning electron microscopy(FESEM), Nadsorption-desorption, and vibrating sample magnetometer(VSM) analysis. Results show that the nanocomposite with tetraethylorthosilicate(TEOS)/cetyltrimethylammonium bromide(CTAB) ratio of 5 exhibits large surface areas(461.19 m~2·g). Furthermore, this nanocomposite shows superparamagnetic behavior under external magnetic field compared to other samples. Moreover, results of removal of metal ions indicate that adsorption of Ni(II), Cd(II), Cr(III),Zn(II), and Pb(II) ions on the surface of adsorbent(nanocomposite) increases with the increase in solution pH, contact time,and adsorbent dosage. Furthermore, the maximum removal rates of heavy metals ions reach 53.0 %, 79.0 %, 61.0 %,89.0 %, and 99.5 % at pH of 5, time of 50 min, and the weight of adsorbent of 0.16 with 2.5 ml TEOS, respectively.展开更多
基金supports rendered by Zhejiang Normal University(Grant No.YS304221928)Iran National Science Foundation.No.:4002219Yonsei University Mirae Campus.
文摘CO_(2)reformation of methane(CRM)and CO_(2)methanation are two interconnected processes with significant implications for greenhouse gas reduction and sustainable energy production for industrial purposes.While Nibased catalysis suffers from poor stability due to coke formation or sintering,we report a super stable remedy.The active sites of mesoporous MgO were loaded using wet impregnation.The incorporation of Ni and promoters altered the physical features of the catalysts.Sm–Ni/MgO showed the smallest crystallite size,specific surface area,and pore volume.The Sm–Ni/MgO catalyst was selected as the most suitable candidate for CRM,with 82%CH4 and H2/CO ratio of approximately 100%and also for CO_(2)methanation with the conversion of carbon dioxide(82%)and the selectivity toward methane reaches 100%at temperatures above 300ᵒC.Furthermore,the Sm–Ni/MgO catalyst was stable for 900 min of continuous reaction,without significant carbon deposition.This stability was largely due to the high oxygen mobility on the catalyst surface in the presence of Sm.Overall,we demonstrated the efficacy of using promoted Ni catalysts supported by mesoporous magnesia for the improved reformation of greenhouse gases.
基金financially supported by the Semnan University Foundation of Iran
文摘In this study, mesoporous silica/iron oxide nanocomposite(MCM-FeO) was synthesized via hydrothermal technique. The chemical synthesis of MCM-FeOnanocomposite was achieved at 18 h. The effect of concentration of tetraethylorthosilicate(TEOS) on nanocomposites properties was studied during synthesis process. For this purpose, 0.5, 1.5, 2.5, 3.5, and 4.5 ml tetraethylorthosilicate(TEOS) were selected, respectively. The textural properties and microstructure of the nanocomposites were characterized by X-ray diffraction(XRD), Fourier transform infrared spectroscopy(FTIR), field emission scanning electron microscopy(FESEM), Nadsorption-desorption, and vibrating sample magnetometer(VSM) analysis. Results show that the nanocomposite with tetraethylorthosilicate(TEOS)/cetyltrimethylammonium bromide(CTAB) ratio of 5 exhibits large surface areas(461.19 m~2·g). Furthermore, this nanocomposite shows superparamagnetic behavior under external magnetic field compared to other samples. Moreover, results of removal of metal ions indicate that adsorption of Ni(II), Cd(II), Cr(III),Zn(II), and Pb(II) ions on the surface of adsorbent(nanocomposite) increases with the increase in solution pH, contact time,and adsorbent dosage. Furthermore, the maximum removal rates of heavy metals ions reach 53.0 %, 79.0 %, 61.0 %,89.0 %, and 99.5 % at pH of 5, time of 50 min, and the weight of adsorbent of 0.16 with 2.5 ml TEOS, respectively.