INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2022
·
IF 7.139
Hui Wang,Hao Zhu,Yuelan Zhang,Jianglong Pu
A series of CTAB-templated Ni/Ce catalysts were synthesized by adding CTAB during the hydrothermal synthesis of ceria to improve the pore structure of catalysts. Their catalytic performance was evaluated in the steam reforming of acetic acid and the effects of CTAB concentration on the porous structures , reducibilities , morphology, and activity of catalysts were studied. The catalysts were characterized by BET, XRD , H 2 -TPR, XPS , HRTEM , in-situ DRIFTS , DTG , FTIR , and temperature-programmed reaction to elucidate the structure-activity relationship of the catalyst. The results showed that owing to the CTAB assistance, a high surface area of ceria could be achieved, which induced a better Ni dispersion with a smaller Ni size, strengthened the interaction between Ni and CeO 2 , and promoted the reducibility of Ni, obtaining higher activity and lower methane yield than Ni/Ce. Among these prepared samples, Ni/Ce–C6 showed the highest surface area and the best catalytic performance with a hydrogen yield of up to 82.5% even at a low temperature (550 °C). Owing to the stronger Ni-ceria interaction of Ni/Ce–C6, the lattice oxygen in ceria migrates easily to the Ni surface , interacts with the reaction intermediates, and thus improves the CO 2 /CO ratio in the products. Much more CO and CO 2 and less CH 4 were observed over Ni/Ce–C6 during the temperature-programmed reaction, indicating its high activity. In-situ DRFITS characterization demonstrated that the two types of catalysts had similar reaction intermediates but various adsorption and conversion abilities toward the acetic acid. More reaction intermediates were adsorbed at low temperatures and a higher conversion was obtained over Ni/Ce–C6 owing to its better Ni dispersion. The CTAB assistance inhibited the formation of amorphous carbon but facilitated the formation of graphitic carbon at ∼637 °C which did not induce catalyst deactivation .
研究领域:
化学工程
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催化材料科学
✓ 已验证
DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2025
·
IF 8.3
Jinxu Zhang,Fusheng Yang,Tao Fang,Bin Wang,Qingyuan Yang,Zhen Wu,Zaoxiao Zhang
The N-ethylcarbazole/dodecahydro-N-ethylcarbazole system, which offers advantages such as excellent hydrogen storage capacity, good reversibility, and reliable safety, is recognized as a potential candidate for hydrogen storage. However, the inefficient dehydrogenation by existing catalysts limits the commercial application of the system. In this work, CTAB was used as the soft template to increase the specific surface area of CeO 2 supports, and further the active metals were formed upon them through various reduction methods. A series of Pd/CeO 2 catalysts were thus prepared, among which Pd/CeO 2 –C6 adopted a composite strategy of using CTAB as the template to increase the specific surface area of CeO 2 and enhancing the dispersion of Pd through ultrasound assisted reduction, showed the best catalytic dehydrogenation performance for 12H-NEC. After 7 h of reaction at 453 K, the conversion rate of 12H-NEC reached 100 % with 97.24 % of hydrogen released. Combining BET, HRTEM, XPS, CO-pulse chemisorption and other characterization analyses, it was found that the incorporation of CTAB effectively enhanced both the specific surface area and oxygen vacancy concentration of CeO 2 , while ultrasound assisted reduction enabled a small particle size and good dispersion of metal Pd on the support. The strong synergetic effects of support and active metal in Pd/CeO 2 –C6 catalyst largely accounts for its good catalytic performance. This work offers valuable insights and guidance for the development of efficient dehydrogenation catalysts for 12H-NEC.
研究领域:
催化化学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2018
·Vol. 54
·期 7
·5359-5365
·
IF 2.993
Guo Bing,Lin Xiuzhen
A novel hierarchically mesoporous–macroporous tin organophosphonate with intra-framework organic groups is successfully fabricated through a facile hydrothermal route with SnCl 4 ·5H 2 O as tin source and diethylene triamine pentakis(methylphosphonic acid) as organophosphorus source in the presence of cetyltrimethylammonium bromide (CTAB) as the templating agent. The as-prepared hybrid had macroporous structures with the pore size in the range of 0.6–2.1 μm and a specific surface area of 170 m 2 /g. Besides, the pore walls had particle-aggregated mesoporous substructures, consisting of amorphous tin organophosphonates, as characterized by SEM, TEM and N 2 adsorption analysis and wide- and low-angle X-ray diffraction. FT-IR and NMR results indicated the integrity of the organophosphonate groups into the hybrid solid. It was found that the surfactant CTAB played an important role in obtaining macropores, and a possible formation route was proposed.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MATERIALS CHEMISTRY
·
2012
·Vol. 22
·期 11
·4847-4854
·
IF 5.968
Desong Wang,Yandong Duan,Qingzhi Luo,Xueyan Li,Jing An,Leilei Bao,Lei Shi
A new method for the preparation of mesoporous TiO2 with a surface deposited with nanoparticles of Ag and AgBr was developed. Cetyltrimethylammonium bromide (CTAB) was used as both a template agent and bromine source in the preparation process of the mesoporous TiO2. Mesoporous TiO2 containing CTAB was synthesized by a sol–gel method, and was dipped into AgNO3 solution to form a mesoporous AgBr/TiO2 nanocomposite. The AgBr/TiO2 nanocomposite was irradiated by visible light to accelerate photolysis of AgBr, forming mesoporous Ag/AgBr/TiO2 photocatalyst. The Ag/AgBr/TiO2 photocatalyst was characterized by small angle X-ray diffraction (SAXRD), wide angle X-ray diffraction (WAXRD), transmission electron microscopy (TEM), UV-Vis diffuse reflectance spectroscopy (UV-Vis DRS), X-ray photoelectron spectroscopy (XPS), Auger electron spectroscopy (AES) and N2 isothermal adsorption–desorption. Ag/AgBr/TiO2 exhibits high photocatalytic activity for the degradation of methyl orange under visible light irradiation. The photocatalytic reaction follows the first-order kinetics and the rate constant (k) for the degradation of methyl orange photocatalyzed by Ag/AgBr/TiO2 is 63.6, 36.1 and 2.7 times that of mesoporous TiO2 (M-TiO2), commercial TiO2 (P-25), and Ag/AgBr/SiO2, respectively. The recycling runs experiment shows that the photocatalytic stability of the Ag/AgBr/TiO2 photocatalyst is excellent. The visible light photocatalytic mechanism of Ag/AgBr/TiO2 is also discussed.
研究领域:
材料科学
·
光催化化学
·
纳米材料
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环境功能材料
·
表面科学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）