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A study on the ball-milling effect of calcined Mg-Al hydrotalcite on the CO2 adsorption behavior
F. Granados-Correa,J.L. Iturbe-García,J. Bonifacio-Martínez 한양대학교 세라믹연구소 2019 Journal of Ceramic Processing Research Vol.20 No.6
We have investigated the effect of ball-milling over calcined Mg-Al hydrotalcite, with regard to its CO2 adsorption capacity. The prepared materials were systematically characterized by X-ray diffraction, scanning electron microscopy and N2 physisorption measurements. The results reveal an excellent adsorption capacity of CO2 by calcined Mg-Al hydrotalcite; however, when this adsorbent was treated by ball-milling for 2 h, a slight decrease in its CO2 adsorption capacity was observed, mainly attributable to the decreased surface area, total pore volume, pore size and the formation of particle aggregates of the aforementioned hydrotalcite. Therefore, alterations in structure, texture and morphology of calcined Mg-Al hydrotalcite during the ball-milling treatment do not optimize its CO2 adsorption capacity.
Hong Khanh Dieu Nguyen,Toan Dang Nguyen,Dung Ngoc Hoang,Duc Sy Dao,Thao Tien Nguyen,Limphirat Wanwisa,Lan Linh Hoang 한국화학공학회 2017 Korean Journal of Chemical Engineering Vol.34 No.2
Hydrotalcite-like compound containing metal cations such as Mg2+, Al3+ and Ni2+ was characterized using Ni K-edge EXAFS and in situ Ni K-edge XANES techniques for clarifying its bonding environment around Ni2+ sites and structure changes during calcination from room temperature to 550 oC, respectively. At the fixed molar ratio of Mg/Ni/Al of 2/1/1, the results obtained from EXAFS analysis showed a slight blue shift before and after the calcination at 550 oC and a reduction in white line peak; the best fits of the two samples revealed tiny change in coordination number about 7 for Ni-O path but considerable difference for Ni-Mg(Al) path from about 4.5 to 9.5, confirming a modification from brucite like to mixed oxide structure. On the other hand, bond distances of the Ni-O and Ni-Mg paths nearly fixed at about 2.06 Å to 3.0 Å reflected stability of the cationic bond order on each plane, but partial collapse and decomposition of the interlayer formed by water molecules and anion CO3 2− after the calcination. Linear combination fit extracted from the in situ Ni K-edge XANES also confirmed the changes along with the calcination such as slow and fast decreases of brucite fraction at 150 oC and 330 oC, respectively, in corresponding to the mixed oxide fraction increases. The achieved bonding structures were also applied to explain acid-base occurrence of the hydrotalcite-like material, especially the acid sites generated by different static charges along with the bonds. The explanation was illustrated by NH3-TPD method.
Park, Tae-Joon,Kim, Yong-Ae Korean Magnetic Resonance Society 2007 Journal of the Korean Magnetic Resonance Society Vol.11 No.1
Several hydrotalcite compounds calcined with different temperature for applications in a chlorine resistant textile were prepared, and its structural changes in dependence on the temperature were studied by using $^{27}Al$ solid-state nuclear magnetic resonance(NMR) spectroscopy. We found that the Al coordination was partly lowered from octahedral to tetrahedral site as the calcined temperature goes up. And we also investigated the hydrotalcite-treated textile for chlorine resistance by using $^{27}Al$ solid-state NMR spectroscopy.
박태준,김용애 한국자기공명학회 2007 Journal of the Korean Magnetic Resonance Society Vol.11 No.1
Several hydrotalcite compounds calcined with different temperature for applications in a chlorine resistant textile were prepared, and its structural changes in dependence on the temperature were studied by using 27Al solid-state nuclear magnetic resonance(NMR) spectroscopy. We found that the Al coordination was partly lowered from octahedral to tetrahedral site as the calcined temperature goes up. And we also investigated the hydrotalcite-treated textile for chlorine resistance by using 27Al solid-state NMR spectroscopy.
( Thuy Duong Nguyen ),( Boi An Tran ),( Ke Oanh Vu ),( Anh Son Nguyen ),( Anh Truc Trinh ),( Gia Vu Pham ),( Thi Xuan Hang To ),( Thanh Thao Phan ) 한국부식방식학회(구 한국부식학회) 2020 Corrosion Science and Technology Vol.19 No.2
This work examined the corrosion protection performance of benzoate loaded hydrotalcite/graphene oxide (HT/GO-BZ) for carbon steel. HT/GO-BZ was fabricated by the co-precipitation method and characterized by infrared spectroscopy, X-ray diffraction, and scanning electronic microscopy. The corrosion inhibition action of HT/GO-BZ on carbon steel in 0.1 M NaCl solution was evaluated by electrochemical measurements. The benzoate content in HT/GO-BZ was determined by UV-Vis spectroscopy. Subsequently, the effect of HT/GO-BZ on the corrosion resistance of the water-based epoxy coating was investigated by the salt spray test. The obtained results demonstrated the intercalation of benzoate and GO in the hydrotalcite structure. The benzoate content in HT/GO-BZ was about 16%. The polarization curves of the carbon steel electrode revealed anodic corrosion inhibition activity of HT/GO-BZ and the inhibition efficiency was about 95.2% at a concentration of 3g/L. The GO present in HT/GO-BZ enhanced the inhibition effect of HT-BZ. The presence of HT/GO-BZ improved the corrosion resistance of the waterborne epoxy coating.
Artit Ausavasukhi,Nattanitcha Krukrathok,Pancheewa Singthaisong 한국공업화학회 2023 Journal of Industrial and Engineering Chemistry Vol.117 No.-
Thermal transformation of copper incorporated hydrotalcite-derived oxides is investigated in ethanoldehydrogenation. Among the copper supported catalyst c-10Cu/HT600 prepared by impregnation of thermallytreated hydrotalcite at 600 C with Cu(NO3)2 solution followed by a calcination provides a high catalyticactivity, selectivity and stability. XRD, DR-UV, TGA, H2-TPR, CO2-TPD, TEM and XPS techniquesreveal that the nature of the copper species depended on the thermal treatment process and support. Such treatment at high temperatures yields a homogeneous dispersion mixed metal oxide. After copperincorporation generated CuAl2O4 spinel structure linked to the copper oxide species can suppress copperagglomeration leading to the catalytic stability. Moreover, the c-10Cu/HT600 catalyst can provide a highactivity and high selectivity to acetaldehyde even at low reaction temperatures (200 C). However, thecopper species may agglomerate to form relatively larger clusters upon increasing metal loading leadingto the deactivation.
니켈계 유사 하이드로탈사이트 촉매상에서 n-헥사데칸의 수증기 개질에 의한 수소 생산
이승환,문동주 한국수소및신에너지학회 2010 한국수소 및 신에너지학회논문집 Vol.21 No.5
Steam reforming of n-hexadecane, a major component of diesel over Ni-based hydrotalcite-like catalyst was carried out at 900℃ at atmospheric pressure with space velocity of 10,000h-1 and feed molar ratio of steam/carbon=3.0. Ni-based hydrotalcite catalyst was prepared by a solid phase crystallization (spc) method and characterized by N2-physisorption, CO chemisorption, TPR, XRD, and TEM techniques. It was found that spc–Ni/MgAl catalyst showed higher catalytic stability and inhibition of carbon formation than Ni/γ-Al2O3 catalyst under the tested conditions. The results suggest that the modified spc-Ni/MgAl catalyst after optimization may be applied for the SR reaction of diesel.
Hoon Sub Song,Soon Jin Kwon,William S. Epling,Eric Croiset,Sung Chan Nam,Kwang Bok Yi 한국청정기술학회 2014 청정기술 Vol.20 No.2
합성가스를 생산하기 위한 부분산화, 이산화탄소 리포밍, 메탄에 의한 산화CO2 리포밍 공정들은 니켈 하이드로탈사이트 (Ni0.5Mg2.5Al) 촉매를 이용하여 수행되었고 안정한 이중층 구조를 형성시키기 위한 금속지지체(Mg, Ca)의 영향에 대해서도 다양한 연구가 진행되었다. 지지체전구물질(Mg, Ca)에 따라 메탄 리포밍의 안정성은 활성니켈이온과 지지체금속이온 사이의 결합강도차이에 의해 영향을 받는다. Ni-Mg-Al 구성체는 가장 안정한 하이드로탈사이트 이중층 구조이지만 Ni-Ca-Al 구성체는 그렇지 않다. 이산화탄소 리포밍 장기테스트에서 Ni-Mg-Al 촉매는 약 100시간 동안 80%의 효율을 유지하면서 탁월한 안정성을 보였지만 Ni-Ca-Al 촉매는 반응초기에 불활성화됨을 확인할 수 있었다. 활성금속 Ni과 지지체 Mg-Al 사이의 결합강도를 확인하기 위해 승온 환원(temperature-programmed reduction, TPR) 분석을 시행하였다. 이를 통해 Ni-Mg-Al 촉매가 Ni-Ca-Al 촉매보다 Ni의 환원온도가 더 높음을 확인할 수 있었다. Ni0.5Ca2.5Al 촉매는 가장 높은 초기반응성을 보였지만 코크형성으로 인해 반응성이 빠르게 감소하였다. 결론적으로 Ni0.5Mg2.5Al 촉매가 코크형성에 대한 강한 저항성을 갖고 있기 때문에 다른 촉매들보다 높은 반응성과 안정성을 갖는 것으로 보여진다. Partial oxidation, CO2 reforming and the oxidative CO2 reforming of CH4 to produce synthesis gas over supported Ni hydrotalcite-type (Ni0.5Mg2.5Al catalyst) catalysts were carried out and the effects of metal supports (i.e.; Mg and Ca) on the formation of a stable double-layer structure on the catalysts were evaluated. The CH4 reforming stability was determined to be affected by the differences in the interaction strength between the active Ni ions and support metal ions. Only a Ni-Mg-Al composition produced a highly stable hydrotalcite-type double-layered structure; while the Ni-Ca-Al-type composition did not. Such structure provides excellent stability for the catalyst (-80% efficiency) as confirmed by the long-term CO2 reforming test (-100 h), while the Ni-Ca-Al catalyst exhibited deactivation phases starting at the beginning of the reaction. The interaction strength between the active metal (Ni) and the supporting components (Mg and Al) was determined by temperature-programed reduction (TPR) analyses. The affinity was also confirmed by the TPR temperature because the Ni-Mg-Al catalyst required a higher temperature to reduce the Ni relative to the Ni-Ca-Al catalyst. The highest initial activity for synthesis gas production was observed for the Ni0.5Ca2.5Al catalyst; however, this activity decreased quickly due to coke formation. The Ni0.5Mg2.5Al catalyst exhibited a high reactivity and was more stable than the other catalysts because it had a higher resistance to coke formation.
Selective hydrogenation of furfural to cyclopentanone over Cu-Ni-Al hydrotalcite-based catalysts
Hongyan Zhu,Guomin Xiao,Minghao Zhou,Zuo Zeng,Rui Xiao 한국화학공학회 2014 Korean Journal of Chemical Engineering Vol.31 No.4
A series of Cu-Ni-Al hydrotalcites derived oxides with a (Cu+Ni)/Al mole ratio of 3 with varied Cu/Nimole ratio (from 0.017 to 0.5, with a Cu ratio of 0.0125 to 0.25) were prepared by co-precipitation method, then appliedto the hydrogenation of furfural in aqueous. Their catalytic performance for liquid phase hydrogenation of furfural toprepare cyclopentanone was described in detail, considering reaction temperature, catalyst composition, reaction timeand so on. The yield of cyclopentanone was influenced by the mole ratio of Cu-Ni-Al based heterogeneous catalystand depended on the reaction conditions. The yield of cyclopentanone was up to 95.8% when the reaction was carriedout under 413 K with H2 pressure of 40 bar for 8 h. The catalysts were characterized by X-ray powder diffraction (XRD),scanning electron microscope (SEM) and H2 temperature-programmed reduction (H2-TPR).