Catalysts
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2021
·Vol. 11
·期 4
·441
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IF 4.146
Yun Chen,Xinlei Ding,Wenge Qiu,Jianwei Song,Junping Nan,Guangmei Bai,Siping Pang
The influence of the surface chemical properties of the carbon support on the Pd dispersion, activity and stability of Pd(OH)2/C catalyst for the hydrogenolytic debenzylation of tetraacetyldibenzylhexaazaisowurtzitane (TADB) was studied in detail. The flowerlike nanosheet carbon material (NSC) was chosen as the pristine support, meanwhile chemical oxidation with nitric acid and physical calcination at 600 °C treatments were used to modify its surface properties, which were denoted as NSCox-2(treated with 20 wt% HNO3) and NSC-600, respectively. The three carbon supports and the corresponding catalysts of Pd/NSC, Pd/NSC-600, and Pd/NSCox-2were characterized by scanning electron microscope (SEM), transmission electron microscopy (TEM), nitrogen sorption isotherm measurement (BET), powder X-ray diffraction (XRD), Raman spectra, X-ray photoelectron spectra (XPS), temperature-programmed desorption (TPD), temperature-programmed reduction (H2-TPR), thermogravimetric analysis (TG), and element analysis. The debenzylation activities of Pd/NSC, Pd/NSC-600, and Pd/NSCox-2, as well as the three catalysts after pre-reduction treatment were also evaluated. It was found that the activity and stability of the Pd(OH)2/C catalysts in the debenzylation reaction highly depended on the content of surface oxygen-containing groups of the carbon support.Keywords:palladium catalyst;hydrogenolytic debenzylation;surface oxygen-containing groups;palladium dispersion
研究领域:
催化
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材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
Materials Today Communications
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2022
·
IF 3.662
Yingjun Li,Yakun Guo,Zekun Jing,Xingtao Zhao,Yuanlin Zhou,Maobing Shuai
To solve the problems of hydrogen embrittlement and explosion risk generated by the use of hydrogen energy in large-scale applications, organic hydrogen getters have been used to eliminate hydrogen in sealed systems and related fields. However, the hydrogen absorption rate of existing hydrogen getters needs to be further improved. Herein, a three-dimensional (3D) N-doped carbon with interconnected hierarchical pores loaded with a uniform dispersion of palladium particles (6.8 nm) was successfully developed. This material was used as a catalyst for 1,4-bis(phenylethynyl)benzene (DEB) hydrogenation under mild conditions, exhibiting good catalytic performance. The hydrogen uptake performance of this Pd/MFC/DEB getter for the reduction of hydrogen gas was examined at 0 – 1 bar and 25 ℃ with hydrogen consumption evaluated with time. The prepared Pd/MFC/DEB getter demonstrated a hydrogen uptake of 212.2 cm 3 /g after about 20 h, which was significantly higher than that of a typical Pd/AC/DEB pallet getter (162.0 cm 3 /g). This was due to the interactions between the Pd and MFC support, which enhanced the dispersion of Pd, increased the area available for the reaction with DEB, promoted the hydrogen dissociation process, and improved the hydrogen spillover effect. This research offers a highly promising approach for the use of MFC as a catalyst support material in hydrogen getters.
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
JOURNAL OF CATALYSIS
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2017
·
IF 6.844
Qiguang Dai,Qin Zhu,Yang Lou,Xingyi Wang
ZSM-5 zeolites (NaZSM-5, HZSM-5 and Silicalite-1) with different acid nature were synthesized and used as supports of Pd catalysts for catalytic combustion of methane. Moreover, the acid property of the as-synthesized Pd/NaZSM-5 catalyst was adjusted by a NH 4 + ion-exchange process to post-generate Brønsted acid sites and different preparation methods were investigated. The potential roles of Brønsted acid sites (anchoring Pd species or activating methane molecules) were discussed, and the experimental results indicated that the anchoring effect of Brønsted acid sites on Pd species was not directly observed. However, the acid properties of supports (the presence of Al 3+ as Lewis acid sites, especially coordinatively unsaturated Al 3+ ) were crucial for the preparation of Pd/ZSM-5 catalysts with high Pd dispersion. Additionally, although Brønsted acid sites of ZSM-5 was contributed to the activation or even cracking of long-chain alkanes (such as n -decane), the direct adsorption/dissociation of methane on Brønsted acid sites was difficult and depended more on the dispersion and particle size of PdO x . Pd/NaZSM-5 catalyst presented an outstanding durability at low-temperature (350 °C) and high-temperature (800 °C), and the high Si/Al ratio could improve the water-resistance due to its good hydrophobicity, but the reversible deactivation owing to the formation of PdO into Pd(OH) 2 under high concentration of water vapor was still unavoidable.
研究领域:
催化化学
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环境科学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING SCIENCE
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2020
·
IF 3.871
Yongwan Gu,Yunyan Li,Jiaoxia Zhang,Huiying Zhang,Chunhua Wu,Jing Lin,Juying Zhou,Yuhang Fan,Vignesh Murugadoss,Zhanhu Guo
Pd/C catalysts were prepared by an incipient-wetness impregnation and their catalytic performance in disproportionation of rosin was investigated. The texture structure, groups on the activated carbon surfaces, and acidity were characterized by N 2 physisorption-desorption, Fourier transform infrared spectroscopy (FTIR), and temperature-programmed desorption (TPD). The Pd/AC3 (treated at 443 K) had the highest Pd dispersion (23.60%) with the highest specific surface area of activated carbon (1057 m 2 /g). Nevertheless, the Pd/AC0 (original carbon black) had the lowest Pd dispersion (13.07%) with a lower specific surface area of original activated carbon (994 m 2 /g). Pd/AC3 presented a considerable catalytic activity in the rosin disproportionation reaction, with 64.15% dehydroabietic acid and without abietic acid in product. However, Pd/AC0 (Pd supported on the original carbon) showed a much lower catalytic activity in the rosin disproportionation reaction, with 42.64% dehydroabietic acid and 3.59% abietic acid in product.
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
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