Chemical Engineering and Processing-Process Intensification
·
2020
·
IF 3.731
Lan Jiang,Guang-Wen Chu,Ya-Zhao Liu,Wei Liu,Li-Xiong Wen,Yong Luo
A rotating packed bed (RPB) reactor with excellent mass transfer performance can be applied for catalytic reactions. However, the structure of catalyst particles randomly inside the rotor of the RPB reactor was easily deformed under the centrifugal field. In this work, a cordierite (COR) monolithic catalyst with high mechanical strength was prepared, aiming to be used in the RPB reactor for hydrogenation. The acid pretreatment and Al 2 O 3 coating were employed to increase the specific surface area of COR substrate. Active component palladium (Pd) was deposited on Al 2 O 3 /COR. Hydrogenation of α-methylstyrene (AMS) was selected as a model reaction for the RPB reactor with the above Pd/Al 2 O 3 /COR. Experimental results show that the space time yield (STY) in the RPB reactor was effectually enhanced 9.2 times higher than that in the fixed bed reactor at the operation conditions of 30 °C and 0.2 MPa, which shows potential prospects of the RPB reactor with Pd/Al 2 O 3 /COR monolithic catalyst for the process intensification of catalytic reaction.
研究领域:
化学工程
·
催化反应
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Xi-Guang Wang,Lu-Yang Qiao,Li-Yuan Xu,Yun-Yun Zeng,Zhi-Shen Huang,Shan-Shan Zong,Jin-Xiang Wang,Zhang-Feng Zhou,Yuan-Gen Yao
The intrinsic nature of irreducible oxides (e.g. Al 2 O 3 ) makes it hard to tune the charge state of supported late-transition metals, then difficult to adjust the selectivity of catalysts in CO 2 hydrogenation. Herein, we find that modifying the Pd/Al 2 O 3 catalyst with alkali metals (especially potassium) is efficient to boost the CO formation in CO 2 hydrogenation. In comparison to Pd/Al 2 O 3 , approximately twenty-fold promotion in reverse water–gas shift (RWGS) rate was achieved on K-modified catalysts with proper K/Pd proportions. Combined structural characterizations demonstrate that the enhanced Pd-O interactions through K mediation stabilize the ca. 2 nm sized Pd particles as well as the electron-deficient state of Pd, which are robust enough during long-termed evaluation with undamped performance. In situ spectroscopy unveils a bi-dentate *HCOO associated reaction mechanism taking effect on alkali-modified catalysts, which contributes to ∼ 100 % of CO selectivity and 3318.1 mmol∙g Pd -1 ∙h −1 of CO formation rate at 340°C.
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
CHINESE JOURNAL OF CHEMICAL ENGINEERING
·
2022
·
IF 3.898
Lu Lv,Min Zhao,Yanan Liu,Yufei He,Dianqing Li
Alumina (Al 2 O 3 ) is widely used in the chemical industry as the catalyst and support due to its high specific surface area, abundant pore size distribution and chemical stability. However, the occurrence of hydration in water environment, result in outstanding decrease in specific surface area and collapse of pore structure. In this work, dodecyl phosphoric acid (PA) is used to modify the surface of Al 2 O 3 to obtain a series of hydrophobic material (Al 2 O 3 -PA). Based on XPS and NMR analysis, PA is chemically bonded on Al 2 O 3 to form P O Al bond. Furthermore, BET and WCA results display that Al 2 O 3 -1PA exhibits excellent the hydrophobicity and hydrothermal stability while maintains the pore structure. Take it as the substrate to support the Pd nanoparticles , the as-prepared Pd/Al 2 O 3 -PA shows the superior catalytic performance in the hydrogenation of phenol and anthraquinone relative to Pd/Al 2 O 3 , indicating the accessibility of Pd sites after PA modification. Especially, the significantly enhanced stability is also obtained in four cycles for aqueous phenol hydrogenation. This can be ascribed that the PA modification inhibits the aggregation of Pd nanoparticles and the products adhesion in the reaction process. The extension of PA coatings to monolithic catalysts could expand their current capabilities in industrial applications and warrants ongoing investigation.
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
ACS Applied Materials & Interfaces
·
2026
·
IF 7.8
Yimeng Zhou,Tingting Chen,Jie Ding,Hao Li,Di Wu,Xuran Xu,Qin Zhong
Controlled hydrogen spillover is of paramount importance for the precise regulation of target products in the hydrogenation selectivity. In this study, Pd@1Al2O3/Ag catalyst was designed and prepared for the hydrogenation-acetalization of diethyl oxalate (DEO) to 1,1-diethoxyethane (DEE) with excellent DEE selectivity (83.0%) and high DEO conversion (99.9%). Pd species are mainly responsible for the generation of H* species from H2 adsorption and dissociation, and Al2O3 acted as a delivery channel for H* species to migrate and mass transfer from H* to Ag nanoparticles loaded on the catalyst surface, which facilitated the progression of subsequent DEO hydrogenation-acetalization reactions. This study provides a promising strategy for high hydrogenation-acetalization efficiency via controllable hydrogen spillover.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Applied Catalysis O: Open
·
2024
·
IF 0
Zhe Zhang,Weiting Xiao,Yufei He,Dianqing Li,Xiaodong Zhao
During the manufacture of Al 2 O 3 , sulfate would be inevitably introduced when aluminum sulfate is used as raw material, but its effect has received little attention. In this work, Al 2 O 3 supports with different sulfate content were synthesized and used to prepare Pd/Al 2 O 3 catalyst. Sulfates in all samples exist as surface sulfate, and would be partially removed during the preparation process. Sulfate existing in Al 2 O 3 supports had little impact on the electric structure of Pd, but would partially block pores and also consume surface hydroxyl groups. As a result, higher sulfate content in support would lead to lower Pd dispersion in catalysts and slower reaction rate towards the hydrogenation of amyl-anthraquinone.
研究领域:
材料科学
·
催化化学
·
物理化学
✓ 已验证
DOI
APPLIED CATALYSIS A-GENERAL
·
2025
·
IF 4.8
Fangxu Shi,Fuxin Liang,Yulin Wei,Junyan Wu,Sai Huang,Honglei Wang,Zhi Wang,Guopu Shi
The hydrogenation-catalyzed synthesis of mirabellone, a drug for the treatment of overactive bladder (OAB), faces the challenge of catalytic efficiency and selectivity regulation of its core intermediate. In this study, we propose an innovative strategy for constructing a Pd/B-Al 2 O 3 composite catalytic system on a foam ceramic substrate using the impregnation method, and systematically investigate the modulation mechanism of different boron doping ratios on the catalyst's performance. Experimental and density functional theory studies demonstrate that the incorporation of boron synergistically enhances surface adsorption of reaction intermediates, facilitates the efficient reduction of PdO, and precisely modulates the distribution of acidic sites, thereby establishing a catalytic environment more favorable for the selective reduction of nitro groups. This catalyst, characterized by its unique three-dimensional pore structure and the interface synergistic effect resulting from boron modification, enables a uniform distribution of catalytically active centers and enhances the efficiency of reaction mass transfer. Through the optimization of process parameters, the yield of the target product was significantly improved, providing an innovative technological path for the preparation of the key intermediate of mirabilon.
研究领域:
催化化学
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材料科学
·
计算化学
·
药物合成
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
ACS Catalysis
·
2025
·
IF 13.1
Tao Wang,Qiao Yu,Zhilin Chen,Chao Xiao,Shuming Peng
The active phase for methane combustion is still in debate. Low-temperature CO-FTIR spectroscopy was used to probe the working surface state on a series of Pd/Al2O3 (PdAl) and Pd/silicalite-1 (PdSil) catalysts with different starting states: oxidized, reduced (R), reoxidized (Ro). The surface of prereduced PdAl (Pd0) is transformed to an oxidized state (PdOx) with a CO stretching vibration (νCO) at ∼2157 cm–1 when it is aged in the methane oxidation mixture. The aging-induced transformation from Pd0 to PdOx occurred at 250 °C or above. Although PdSil has multiple kinds of PdOx entities, prereduced PdSil also transformed into PdOx. For PdAl(4)-R-A250, XRD patterns suggest weak bulk oxidation of Pd0 at 250 °C, XPS spectra indicate 28% of surface Pd0 atoms are oxidized, but CO-FTIR spectra confirm all the “top surface” Pd0 atoms are oxidized. It demonstrates the advantage of CO-FTIR spectroscopy in probing the top surface state. Finally, a direct correlation between operando FTIR spectroscopy and low-temperature CO-FTIR spectroscopy was established. Operando FTIR spectra over PdSil during methane oxidation at 250 °C gives two bands at 2124 cm–1 (CO–Pd+) and 2161 cm–1 (CO–Pd2+). After cooling in nitrogen, CO-FTIR spectra give two similar bands at 2134 cm–1 and 2157 cm–1. The “working surface state” can be preserved in CO-FTIR. For PdAl(4), operando FTIR spectra at 250 and 300 °C give no bands of adsorbed CO. Adding CO into the methane oxidation mixture resulted in a single CO–Pd2+ band at 2163 cm–1, which is in accord with their CO-FTIR spectra. For operando FTIR spectroscopy, the observation of the bands of adsorbed CO depends on the accumulation of the CO intermediates, but their accumulation is limited to reaction temperatures below 300 °C and to PdSil (not PdAl). These limitations make low-temperature CO-FTIR spectroscopy more general and sensitive.
研究领域:
催化化学
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材料科学
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环境化学
·
光谱学
✓ 已验证
产品关联
DOI
高影响因子
Russian Journal of Physical Chemistry A
·
2022
·Vol. 96
·期 9
·1944-1950
·
IF 0.791
Zhang Yuanyang,Bao Kun,Wang Xuchao,Wang Linqi
Abstract A series of Ru and Ru–Pd supported samples on deep desulfurization, especially thiophene-like compounds, were prepared by wet impregnation method. It indicated that the suitable Ru content on the support could be 1.5 wt % (Ru(1.5)/Al 2 O 3 ) under used experimental conditions. The effects of Pd on Ru(1.5)/Al 2 O 3 sample showed that the suitable content of Pd was probably 0.3 wt % (Ru(1.5)–Pd(0.3)/Al 2 O 3 ), and its breakthrough sulfur capacity could be reached to 1.244 g S /kg Cat . XPS and SEM characterization over fresh and used samples of Ru(1.5)–Pd(0.3)/Al 2 O 3 indicated that it had good stable structure. Furthermore, it indicated that the adsorption isotherm model of Freundlich equation was well fitted the experimental data ( R 2 = 0.989) and the parameters of Freundlich equation were obtained by linear regression.
研究领域:
催化化学
·
环境工程
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）