Catalysis Science & Technology
·
2019
·Vol. 9
·期 13
·3454-3468
·
IF 5.726
Huixian Zhong,Jiaming Wang,Kang An,Kegong Fang,Yuan Liu
A catalyst with a novel composition for direct ethanol synthesis from syngas was prepared and investigated in this work, which is Rh nanoparticles (NPs) highly dispersed on La2O3 modified LaFeO3, and the Rh NPs/La2O3–LaFeO3 was loaded on SiO2 with high surface area. The catalyst was prepared by using LaFe1−xRhxO3 in the perovskite phase as the precursor, which was transformed to Rh/La2O3–LaFeO3/SiO2 after reduction. The results showed that, compared to Rh–La2O3/SiO2, the activity and selectivity to ethanol were improved markedly, which was ascribed to the well-matched catalyzing process by the active sites of Rh0, Rh+ (or Rhδ+) and the oxygen vacancies on the surface of LaFeO3; of those, Rh0 dissociatively adsorbed CO and the latter two associatively adsorbed CO. Moreover, the interaction of La2O3 and LaFeO3 donated electrons to rhodium, which effectively adjusted the ratio of CO adsorbed associatively and dissociatively, and thus improved the selectivity to ethanol and lowered the selectivity to methanol. The catalyst also exhibited excellent resistance to the sintering of Rh NPs and to carbon deposition, which was attributed to the confinement of Rh NPs by La2O3 and LaFeO3, the eliminating effect of La2O3 and LaFeO3 and the very high dispersion of Rh NPs.
研究领域:
催化化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2017
·
IF 9.446
Mei Ming,Yanlin Ren,Min Hu,Yun Zhang,Ting Sun,Yuling Ma,Xiaojing Li,Weidong Jiang,Daojiang Gao,Jian Bi,Guangyin Fan
Exploring MXenes as supports for synthesis of highly efficient catalysts are extremely important for hydrodechlorination of chlorophenols because of the acute toxicity and strong potential bioaccumulation of chlorophenols. We reported a facile strategy to synthesize Rh nanoparticles deposited on 2D alk-Ti 3 C 2 X 2 (X = O, F) (alk-Ti 3 C 2 X 2 for short) MXene, which was prepared through the removal of the Al layers of Ti 3 AlC 2 and post-treatment by alkalization. Modifying the Ti 3 C 2 X 2 support by alkalization triggered the substitution of surface fluorine groups with surface oxygen species. The changes in the surface chemistry of alk-Ti 3 C 2 X 2 effectively prevented particle aggregation to form well-dispersed Rh nanoparticles in small sizes with relative high metal dispersion, thereafter improving the hydrogen uptake capacity of the catalyst. Consequently, the Rh/alk-Ti 3 C 2 X 2 catalyst significantly enhanced the catalytic performance for the HDC reaction, which could be assigned to the large number of active components from small Rh nanoparticles. This strategy provides a basis for investigating the use of MXenes as supports to synthesize well-defined metal nanoparticles in 2D layered structures for potential applications.
研究领域:
环境科学
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Nano Materials
·
2023
·
IF 5.9
Xin Ning,Heming Wang,Ganghua Zhou,Longyun Zhang,Yanju Yang,Jingya Sun,Xiaozhi Wang
Ni catalysts decorated with trace Rh supported on γ-Al2O3 were prepared by the co-impregnation method. To obtain the Ni–Rh nanoparticles with different nanostructures and chemical compositions, bimetallic catalysts with varied Ni/Rh molar ratios were prepared. For comparison, monometallic Ni/γ-Al2O3 and Rh/γ-Al2O3 catalysts were also prepared by the impregnation method. The selective gas phase catalytic hydrodechlorination of 1,2-dichloroethane to ethylene was used to evaluate catalytic performances of the catalysts. The catalysts were characterized by X-ray diffraction, N2 adsorption, X-ray photoelectron spectroscopy, H2 temperature-programmed reduction, transmission electron microscopy–energy-dispersive X-ray, and CO chemisorption. It was found that the introduction of Rh to Ni catalyst facilitated the generation of spillover hydrogen which could enhance the ability of the Ni catalyst for H2 activation. In bimetallic catalysts, there was an intimate interaction between Ni and Rh, and isolated Rh sites were formed due to the dilution effect of Ni. Accordingly, compared with the monometallic Ni catalyst for gas phase catalytic hydrodechlorination of 1,2-dichloroethane, the bimetallic Ni–Rh(800)/γ-Al2O3 catalyst exhibited markedly higher 1,2-dichloroethane conversion (37%) and comparable selectivity to ethylene (95%). The findings in this study indicate that Ni–Rh/γ-Al2O3 with trace Rh can be used as a promising catalyst for highly effective and selective catalytic hydrodechlorination of chlorinated hydrocarbons.
研究领域:
化学工程
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催化科学
✓ 已验证
产品关联
DOI
高影响因子
ELECTROCHIMICA ACTA
·
2018
·
IF 5.116
Jian Du,Xilong Wang,Chao Li,Xin-Yu Liu,Lin Gu,Han-Pu Liang
Studies on highly effective electrocatalysts for producing hydrogen via electrochemical water splitting is of great significance due to the increasing demand of clean and sustainable hydrogen energy economy. In this work, hollow RhCo nanoparticles with an average diameter of 21 nm were fabricated using the galvanic replacement method in a water-ice bath. Electrochemical evaluation showed that the as-synthesized electrocatalyst exhibited better performance for hydrogen evolution reaction (HER) under acid condition, with a lower overpotential of 28.1 mV at 10 mA cm −2 and a lower Tafel slope of 24 mV dec −1 , in comparison with commercial Rh/C. The better HER performance of the as-prepared hollow Rh nanoparticles could be attributed to the larger surface area than commercial Rh nanoparticles, which could provide more active sites and therefore improve the electrocatalytic performance.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2018
·
IF 4.229
Jiaqin Chen,Min Hu,Mei Ming,Caili Xu,Yi Wang,Yun Zhang,Jiangtao Wu,Daojiang Gao,Jian Bi,Guangyin Fan
Hydrogen generation from the hydrolysis of ammonia borane (AB) over heterogeneous catalysts is essential for practical applications. Herein, efficient hydrogen evolution from AB hydrolysis over the carbon-supported Rh nanoparticles synthesized with sodium citrate (Rh/C-SC) was achieved at 25 °C. The turnover frequency value of Rh/C-SC was 336 mol H 2 (mol Rh min) −1 , whereas that of Rh/C catalyst only yielded a value of 134 mol H 2 (mol Rh min) −1 . The improvement of the catalytic performance of Rh/C-SC catalyst could be attributed to the small Rh particles with highly active surface areas, which were prepared by using sodium citrate as the stabilizing agent. This result indicates that sodium citrate can be applied as a useful stabilizing agent for synthesizing active metal nanoparticles , thus highly promoting the practical application of AB system for fuel cells.
研究领域:
化学
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材料科学
·
能源研究
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2020
·
IF 10.652
Wenjie Xue,Hongxia Liu,Baohua Mao,Honglei Liu,Minghuang Qiu,Chengguang Yang,Xinqing Chen,Yuhan Sun
Hydrogen is a promising candidate to replace the exhausting fossil fuels. However, it is still a big challenge for hydrogen storage. Liquid organic hydrogen carrier (LOHC), which possesses high safety and purity, easy transport and reversibility, is highly attractive for hydrogen storage. Herein we report a new reusable bimetallic Pd-Rh nanoparticles (NPs) catalyst with synergy effect, boosting both the hydrogenation of N-ethylcarbazole (NEC) and dehydrogenation of dodecahydro-N-ethylcarbazole (12H-NEC), which allows multiple cycles of reversible high-weight% hydrogen storage and uptake in short reaction time. Various ex- and in-situ characterizations evidenced that the superior activity was attributed to the bimetallic Pd-Rh NPs cluster structure on the surface of γ-Al 2 O 3 support. The mechanism of NEC hydrogenation over the Pd-Rh catalyst was proposed and verified by density functional theory (DFT) calculations. Such a strategy can be extended to other LOHCs and sheds light onto the development of LOHCs as energy vectors.
研究领域:
化学工程
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材料科学
·
能源技术
✓ 已验证
产品关联
DOI
高影响因子
APPLIED ORGANOMETALLIC CHEMISTRY
·
2024
·Vol. 38
·期 11
·e7685
·
IF 3.7
Ze-Nan Hu,Fangya Guo,Xiuxiu Zhang,Jie Yu,Yaru Yin,Biying Zhang,Hua-Jun Chen,Meijia Chang,Yiming Wang,Yalei Miao,Lan Zhang,Wenjie Tian,Hong-bin Sun
Hydrazine hydrate as a hydrogen source has a good effect on nitro reduction, but overuse has environmental toxicity and is prone to over-hydrogenation, resulting in low selectivity. Herein, we report a magnetically separable Rh/Fe 3 O 4 (1.26 wt%) catalyst containing an optimal Rh content that can completely convert 3-nitrostyrene to 3-vinylaniline (> 99% selectivity) using a stoichiometric molar ratio of hydrazine hydrate (-NO 2 :N 2 H 4 ·H 2 O = 1:1.5). This is due to the synergy between Rh and Fe 3 O 4 and the natural selectivity of N 2 H 4 ·H 2 O for nitro. The synergy can reduce the activation energy of the reaction (36.6 kJ/mol), increasing the reduction rate of nitro group and avoiding the combination of active hydrogen species (H*) to H 2 as well as the hydrogenation of N 2 H 4 to NH 3 . Moreover, the active H* produced by N 2 H 4 ·H 2 O is different from that produced by H 2 , and excess dose of N 2 H 4 will inevitably yield H 2 thus decline the selectivity.
研究领域:
催化
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化学工程
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
Nanoscale Advances
·
2019
·Vol. 1
·期 10
·3941-3947
·
IF 0
Xiao Li,Yucong Yan,Yi Jiang,Xingqiao Wu,Shi Li,Jingbo Huang,Junjie Li,Yangfan Lin,Deren Yang,Hui Zhang
Hydrolysis of ammonia borane (AB) is a safe and convenient means of H2 production when efficient catalysts are used. Here we report a facile one-pot solvothermal method to synthesize Rh/WO3−x hybrid nanowires. Ultra-small Rh nanoparticles with an average size of ∼1.7 nm were tightly anchored on WO3−x nanowires. Rh/WO3−x catalysts exhibited substantially enhanced activity for hydrolytic dehydrogenation of AB under both dark and visible light irradiation conditions relative to mixed Rh nanoparticles and WO3−x nanowires (Rh + WO3−x), and Rh/C and WO3−x nanowires. X-ray photoelectron spectroscopy (XPS) analysis indicated that the synergistic effect between Rh nanoparticles and WO3−x nanowires was responsible for such an enhancement in activity. Specifically, Rh/WO3−x achieved the highest turnover frequency (TOF) with a value of 805.0 molH2 molRh−1 min−1 at room temperature under visible light irradiation. The H2 release rate as a function of reaction time exhibited a volcano plot under visible light irradiation, indicating that a self-activation process occurred in the hydrolytic dehydrogenation of AB due to additional oxygen vacancies arising from in situ reduction of WO3−x nanowires by AB, and thus an enhanced localized surface plasmon resonance (LSPR). Such a self-activation process was responsible for the enhanced catalytic activity under visible light irradiation relative to that under dark conditions, which was supported by the lower activation energy (45.2 vs. 50.5 kJ mol−1). In addition, Rh/WO3−x catalysts were relatively stable with only little loss in activity after five cycles due to the tight attachment between two components.
研究领域:
催化
·
材料科学
·
纳米技术
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化学工程
·
光化学
✓ 已验证
产品关联
DOI
PubMed
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2025
·
IF 21.1
Wuyi Feng,Jiantao Fu,Xinye Zheng,Wei Zhu,Zhongbin Zhuang,Di Zhao,Jiatao Zhang
Optimizing the intrinsic hydrogen binding energy at atomic-level interfaces is beneficial and challenging for hydrogen electrocatalysis to improve the mass activity of platinum-group metal. Here, we develop a bifunctional hydrogen electrocatalyst featuring atomically dispersed Rh-N 4 sites alongside ultrasmall Rh nanoparticles (Rh SA+NP /NC). For the hydroxide oxidation reaction, the mass activity (9.14 A mg Rh −1 ) of Rh SA+NP /NC is 101 times that of commercial Pt/C. For the hydrogen evolution reaction, the overpotential is merely 14 mV at an extremely low Rh loading (1.91 μg cm −2 ). The anion-exchange membrane fuel cell and anion-exchange membrane water electrolyzer equipped with Rh SA+NP /NC achieve a high peak power density (25.7 W mg Rh −1 ) and a low cell voltage (1.77 V at 1 A cm −2 ), respectively. Experimental and computational results indicate that the atomic-level interface formed by Rh single atoms and nanoparticles optimizes the adsorption behavior of active species and accelerates the hydrogen conversion kinetics. This study designs cost-effective hydrogen electrocatalysts through atomic-level interface engineering, providing a feasible strategy for accelerating the realization of a sustainable hydrogen circular economy.
研究领域:
电催化
·
材料科学
·
能量转换
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纳米材料
·
氢能
✓ 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）