FUEL
·
2020
·
IF 5.578
Hao Qu,Sihui He,Yue Su,Yulong Zhang,Haiquan Su
Direct synthesis of ethanol from syngas (a mixture of H 2 and CO) is considered as an eco-friendly and industrially important process to produce renewable fuels and chemicals. The current non-noble metal catalyst systems suffer from either low selectivity or multiple processes with high energy consumption. Here, we report a novel molybdenum diselenide-based catalyst system for high-selective conversion of syngas into ethanol. For a series of K-promoted MoSe 2 catalysts with different K/Mo ratios (K x -MoSe 2 , x = 0.25-1.00), K 1.00 -MoSe 2 surprisingly exhibits excellent ethanol selectivity up to 58.7 C mol % in total alcohols and 31.1 C mol % in the total product, which is higher than the highest selectivity value for the non-noble metal catalysts reported in the literature. The high ethanol selectivity is attributed to the formation of K-Mo-Se active phase and the synergistic effect of the Mo IV , Mo V and Mo VI multivalent species in the active phase. This study opens up a highly selective non-noble metal catalyst system for the direct synthesis of ethanol by syngas, which is of practical significance for the catalytic conversion of hydrogen-poor syngas.
研究领域:
化学工程
·
催化科学
✓ 已验证
DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2017
·
IF 9.446
Chunmei Cao,Lingli Xing,Yuexi Yang,Ye Tian,Tong Ding,Jing Zhang,Tiandou Hu,Lirong Zheng,Xingang Li
Herein, we report the high catalytic activity of the potassium-promoted Co 3 O 4 nanowires supported on the monolithic three-dimensional macroporous (3-DM) nickel foam substrate (xKCo-NW) for soot combustion. The 3-DM structure of Ni foam and the space among these nanowires can extremely improve the contact efficiency between soot and catalysts. Loading of potassium provides the new active sites for soot oxidation , improves catalyst-soot contact as a molten salt and increases the number of the surface adsorbed oxygen species. The 5KCo-NW catalyst loaded with 5% potassium shows the highest catalytic performance, as well as a high water resistance. There are two types of potassium species in the catalysts, most potassium species is in the form of separate phases, and few interacts with cobalt oxide. The interaction between potassium species and cobalt oxide stabilizes a part of potassium species, and the stabilized potassium species can promote the catalytic activity for the consecutive soot combustion cycle. Moreover, our results show that the chemisorbed NO x species on the 5KCo-NW catalyst are more active than the gaseous NO 2 for soot oxidation. In the presence of O 2 , soot combustion is accelerated to react with the chemisorbed NO x species; whereas the formed nitrate/nitrite species are catalytically inert.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
CHEMOSPHERE
·
2022
·
IF 8.943
Ying Xiong,Yumei Zhao,Weijun Shan,Xiaogeng Feng,Junshuo Cui,Zhenning Lou,Guoxiang Shao,Min Dong,Haibiao Yu
In order to enhance the catalytic performance of the Gd-modified Co 3 O 4 catalyst (Gd 0.06 Co) for the N 2 O decomposition, alkali metal K was introduced as the promoter by impregnating the Gd 0.06 Co powder with an aqueous solution of KNO 3 (with K/Co ratios 0.01–0.05). With the doping of K, the catalytic activity over Gd 0.06 Co was significantly improved and the temperature of N 2 O complete decomposition was decreased from 350 °C to 300 °C. Combining the results of XPS and O 2 -TPD, the superior catalytic performance of the optimum catalyst K 0.025 Gd 0.06 Co was mainly owing to the synergistic effect of Gd and K, which weakened the Co–O bond and endowed the catalyst surface with much more amount of oxygen vacancies. Even under the coexist of the impurity gases, such as 5 vol% O 2 , 100 ppmv NO and 2 vol% H 2 O, the K 0.025 Gd 0.06 Co catalyst exhibited prominently better catalytic activity than Gd 0.06 Co and K 0.025 Co catalysts.
研究领域:
催化化学
·
环境科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CATALYSIS TODAY
·
2017
·
IF 4.636
Zhibiao Shi,Haiyan Yang,Peng Gao,Xiaopeng Li,Liangshu Zhong,Hui Wang,Hongjiang Liu,Wei Wei,Yuhan Sun
A series of TiO 2 supported Co–Cu catalysts with the weight percent of potassium oxides ranged from 0 to 3.5 wt.% were synthesized. This work investigates the influence of potassium promoter on CO 2 hydrogenation to long-chain (C 5+ ) hydrocarbons. The introduction of suitable amount of K into the CoCu/TiO 2 catalyst remarkably promoted the formation of C 5+ hydrocarbons and suppressed methane formation. The temperature-program desorption measurements demonstrate that the addition of K increases the chemisorption of CO 2 , whereas H 2 adsorption is decreased, which enhanced production of liquid fuels. However, these effects were not obvious with the addition of excess amount of K due to the slight change of surface K content. A maximum C 5+ yield with CO 2 conversion of 13% and C 5+ selectivity of 35.1 C-mol% is obtained over the CoCu/TiO 2 catalyst with 2.5 wt.% of potassium promoter loading, which also exhibits a substantial stability.
研究领域:
催化化学
·
能源科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
Reaction Kinetics Mechanisms and Catalysis
·
2022
·Vol. 135
·期 5
·2457-2473
·
IF 1.843
Huang Jielang,Zhu Zongbo,Zhang Dandan,Li Xiaoguo,Hou Zhanggui,Zhang Yi
A series of iron supported carbon foam catalysts (10Fe/CF) were successfully synthesized via a facile method by impregnation to reveal the influence of a superior diffusion performance on the Fischer–Tropsch synthesis (FTS) reaction. Meanwhile, different amounts of potassium (0–1.5 wt%) were investigated on 10Fe/CF catalyst by the fixed-bed reactor and typical FTS reaction conditions (300 °C, 1.0 MPa). Various characterizations, including XRD, XPS, Raman, SEM etc. were combined to study the structure, texture, diffusion and Fe phase state. The results revealed that 10Fe/CF catalysts showed superior surface area and FTS performance after the addition of K promoter. Significantly, the addition of K facilitated the formation of C-poor iron carbides, contributing to enrich the reactivity for the syngas to light olefins.
研究领域:
化学工程
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
FUEL
·
2018
·
IF 4.908
Wenzhi Li,Mingxue Su,Tingwei Zhang,Qiaozhi Ma,Wei Fan
Liquid fuel intermediates can be produced via aldol condensation reactions between furfural and acetone. It was found that potassium-promoted Lewis acid zeolite Sn-MFI performed superior catalytic performance for C C bond coupling by aldol condensation reactions of furfural with acetone. The presence of K in Sn-MFI catalyst improves the catalytic activity of the catalyst likely due to increased basicity. The product distribution of aldol condensation was also changed remarkably with the addition of K. Besides 4-(2-furyl)-3-buten-2-one (FAc), 1, 5-di-2-furanyl-1, 4-pentadien-3-one (F 2 Ac) was also formed in the existence of K compared with pure Sn-MFI. It was also found that the K-promoted Sn-MFI catalyst is more resistant to water and exhibits enhanced selectivity to F 2 Ac.
研究领域:
化学工程
·
催化科学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2022
·
IF 16.744
Jie Zhou,Hao Liu,Chao Xiong,Peng Hu,Hao Wang,Xuyu Wang,Hongbing Ji
Propane dehydrogenation (PDH) has been a promising method to satisfy the increasing demand for propylene, but Pt-based catalysts always suffer from sintering and coke formation. Developing stable and efficient catalysts for PDH is of great significance for the industry. Herein, the paper reports that a catalyst with potassium-promoted Pt-In bimetallic clusters encapsulated in silicalite-1 (S-1) zeolite works as an efficient and stable catalyst for PDH. The catalyst achieves a propane conversion of 43.73 % with 97.14 % selectivity of propene and an extremely high propylene productivity of 20.33 mol g Pt -1 h -1 with a weight hourly space velocity (WHSV) of 6.75 h −1 . No obvious deactivation occurs after 48 h on stream, affording an extremely low deactivation constant of 0.0025 h −1 . The introduction of indium species greatly improves the propene selectivity and restricts the coke formation. The introduction of K + into S-1 can significantly enhance the catalytic activity and the stability of the catalyst. The catalyst with excellent activity and stability is potential for industrial application.
研究领域:
催化
·
化学工程
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING SCIENCE
·
2024
·
IF 4.1
Xuanbei Peng,Yongjin Luo,Tianhua Zhang,Jinxiu Deng,Yanliang Zhou,Jiaxin Li,Jun Ni,Bingyu Lin,Jianxin Lin,Dongshuang Wu,Lirong Zheng,Xiuyun Wang,Lilong Jiang
The effects of promoters on Ru nanoparticles (≥2 nm) catalysts for NH 3 synthesis have been extensively elaborated, but their roles on ultrasmall Ru nanoclusters (NCs, 1–2 nm) remain largely unknown and need to be further uncovered. Herein, a series of K-promoted MgO supported Ru NCs were synthesized and investigated for NH 3 synthesis. The addition of 5wt.%K onto Ru/MgO NCs leads to a significantly high NH 3 synthesis rate of 21.7 mmol NH3 g cat −1 h −1 at 400 °C and 0.2 MPa, close to the thermodynamic equilibrium. Out studies reveal that anchoring K onto Ru NCs can increase the electron density and cause an upshift of the d -band center of Ru entities. Moreover, the addition of K regulates the hydrogen affinity and accelerates the migration of hydrogen from the Ru NCs surface to MgO support, which is crucial in avoiding the hydrogen poisoning effect on Ru NCs. With the synergistic effect of the Ru NCs sites bridged by H-spillover, makes the K-mediated Ru/MgO NCs catalysts efficient for NH 3 synthesis at mild conditions.
研究领域:
催化
·
材料科学
·
化学工程
·
物理化学
✓ 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）