Engineering
·
2021
·
IF 7.553
Xinyu Cao,Tiancheng Pu,Bar Mosevitzky Lis,Israel E. Wachs,Chong Peng,Minghui Zhu,Yongkang Hu
Reductive pretreatment is an important step for activating supported metal catalysts but has received little attention. In this study, reconstruction of the supported nickel catalyst was found to be sensitive to pretreatment conditions. In contrast to the traditional activation procedure in hydrogen, activating the catalyst in syngas created supported Ni nanoparticles with a polycrystalline structure containing an abundance of grain boundaries. The unique post-activation catalyst structure offered enhanced CO adsorption and an improved CO methanation rate. The current strategy to tune the catalyst structure via manipulating the activation conditions can potentially guide the rational design of other supported metal catalysts.
研究领域:
催化化学
·
材料科学
✓ 已验证
DOI
高影响因子
NANO
·
2016
·
IF 0.951
Jingge Liu,Ang Cao,Jing Si,Lihong Zhang,Qinglan Hao,Yuan Liu
Sintering of the active metallic nanoparticles and carbon deposition are the key problems faced for CO methanation catalysts. For overcoming those problems, bimetallic nanocatalyst is a promising route. In this work, a series of Al 2 O 3 supported Ni-Co alloy catalysts were prepared by reducing NiCoAl layered double hydrotalcite (LDHs), and characterized with X-ray diffraction (XRD), temperature programmed reduction TPR, N 2 adsorption-desorption, transmission electron microscopy (TEM) and temperature programed oxidation (TPO) techniques. The resultant catalysts were mesoporous with nanoparticles of Ni-Co alloy ranging from 7.9 nm to 9.2 nm which were highly dispersed in alumina matrix. The sample Ni 7 Co 3 -Al 2 O 3 catalysts showed very good catalytic performance during the stability test at 500/600 ∘ C for 300 h, meanwhile exhibited excellent anti-sintering ability and anti-carbon deposition ability, owing to the formation of Ni-Co alloy and the feature of LDHs. This strategy for improving anti-sintering and anti-carbon deposition should be extendable for catalysts of other reactions.
研究领域:
材料科学
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
ChemCatChem
·
2024
·
IF 3.8
Chao Wang,Chunqun Qin,Mingzheng Liao,Yanping Du,Jiming Gao,Yanbing Wu
High-entropy oxides (HEOs), known for their excellent thermodynamic stability due to their high-entropy effect. In this study, high-entropy (NixAlCoCrMn)3O4 oxides of spinel structure were synthesized by sol-gel method. This HEO has a self-reconfiguration properties in the reaction, and its internal Ni and Co ions exsolve to form a uniformly dispersed NiCot alloy on the surface. The increase of Ni content promotes the exsolution of Ni and Co ions from the interior of the spinel. The high-entropy with a large number of oxygen vacancies not only possesses a stable structure to limit the migration of NiCo alloys, but also enhances the hydrogen overflow. In the CO methanation reaction, it has 99% CO conversion with 87% methane selectivity within 400 oC, and it is stable in the long-term test. This work provides a new idea for exploring the use of high-entropy materials to improve thermal catalytic activity and stability.
研究领域:
材料科学
·
催化化学
✓ 已验证
DOI
高影响因子
Particuology
·
2021
·
IF 3.067
Huilin Yi,Shuliang Lu,Jiajia Wu,Yujun Wang,Guangsheng Luo
In this paper, we present a parallelized microfluidic device with improved ladder–tree distributors for the scaled-up production of monodisperse microspheres. Owing to the improved distribution form comprising a ladder distributor in the center and tree distributors around the circumference, the uniformity of the generated droplets for our device was improved by 32.9% and 86.1% compared to those achieved in devices with conventional tree and ladder distributors, respectively, in the final production stage with 32 droplet generators, indicating the potential of our device for further scale-up while maintaining the monodispersity of the generated droplets. The effect of the 2D scale-up of our device was investigated by varying the continuous-phase flow rate and viscosity. Using our device, γ-Al 2 O 3 microspheres with a diameter of 598.1 μm and a CV of 2.58%, as catalyst support for microreactors, were continuously synthesized at high production rate. The nickel-based catalyst prepared from γ-Al 2 O 3 microspheres with large specific surface area and pore volume had an average NiO size of 14 nm, which was 60.9% of that supported on industrial support. The CO methanation conversion of the Ni@Al 2 O 3 microspheres was 1.7 times larger than Ni@Al 2 O 3 industrial support at 140 °C.
研究领域:
化学工程
·
材料科学
·
催化反应
✓ 已验证
DOI
高影响因子
Frontiers of Chemical Science and Engineering
·
2017
·Vol. 11
·期 4
·613-623
·
IF 1.712
Tang Honggui,Li Shuangshuang,Gong Dandan,Guan Yi,Liu Yuan
Carbon deposition and sintering of active components such as nano particles are great challenges for Ni-based catalysts for CO methanation to generate synthetic natural gas from syngas. Facing the challenges, bimetallic catalysts with different Fe content derived from layered double hydroxide containing Ni, Fe, Mg, Al elements were prepared by co-precipitation method. Nanoparticles of Ni-Fe alloy were supported on mixed oxides of aluminium and magnesium after calcination and reduction. The catalysts were characterized by Brunner-Emmett-Teller (BET), X-ray diffraction, hydrogen temperature programmed reduction, inductively coupled plasma, X-ray photoelectron spectroscopy, transmission electron microscopy and thermogravimetric techniques, and their catalytic activity for CO methanation was investigated. The results show that the Ni-Fe alloy catalysts exhibit better catalytic performance than monometallic catalysts except for the Ni4Fe-red catalyst. The Ni2Fe-red catalyst shows the highest CO conversion (100% at 260–350 °C), as well as the highest CH 4 selectivity (over 95% at 280–350 °C), owing to the formation of Ni-Fe alloy. In stability test, the Ni2Fe-red catalyst exhibits great improvement in both anti-sintering and resistance to carbon formation compared with the Ni0Fe-red catalyst. The strong interaction between Ni and Fe element in alloy and surface distribution of Fe element not only inhibits the sintering of nanoparticles but restrains the formation of Ni clusters.
研究领域:
催化化学
·
材料科学
·
能源化学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）