Molecular Catalysis
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2023
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IF 4.6
Xiaozhong Wang,Jiali Hu,Cai Xu,Yingqi Chen,Liyan Dai
Herein, a series of NiCu/Al 2 O 3 catalysts were prepared by impregnation method and subsequent thermal treatment under different reduction temperatures. The catalysts exhibited excellent catalytic activity for the amination of diethylene glycol (DEG), and satisfactory yield of tertiarybutylaminoethoxyethanol (TBEE) could be obtained. XRD, N 2 adsorption-desorption, SEM, TEM, XPS, and H 2 -TPR were employed to characterize the catalysts, the interaction between Ni and Cu on the catalytic activity was studied. It was found that NiCu alloy was formed after catalyst reduction, which strengthened the reduction ability of NiO and increased the number of Ni 0 active center, contributing to the enhanced catalytic activity. Moreover, the effects of reaction parameters on catalytic activity were explored. There was no need for a solvent, only 3 molar equivalents of tert‑butylamine (TBA) and 1 wt.% catalyst was required. After 7 h of reaction at 220 °C, satisfactory conversion (89.6%) and selectivity (84.6%) were obtained over the prepared catalyst. Cycle experiment demonstrated that the prepared catalyst retained excellent stability and reusability after six runs without significant loss of catalytic activity. This work provided an efficient catalyst for the catalytic amination of diethylene glycol with tert‑butylamine to TBEE.
研究领域:
化学工程
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催化科学
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DOI
高影响因子
ACS Catalysis
·
2020
·
IF 12.35
Shengbo Zhang,Mei Li,Lisheng Li,Fabrice Dushimimana,Jiankang Zhao,Shuai Wang,Jinyu Han,Xinli Zhu,Xiao Liu,Qingfeng Ge,Hua Wang
Regulating electron density at the active site by integrating contributions from multiple channels is an effective strategy to accelerate the reaction rate. Herein, the hydrolysis of ammonia borane (AB) is systematically studied on the NiCu alloy-loaded carbon nitride nanosheets (NixCuy/CNS). The TOF of AB hydrolysis for NiCu/CNS catalyst under visible light irradiation was nearly 3.5 times higher than that in the dark. Photoelectrochemical characterizations indicate that the improved photocatalytic activities originate from a combination of alloying effect, Mott–Schottky junction at the metal–semiconductor interface as well as the localized surface plasmon resonance induced under the visible light irradiation, which synergistically increase the local electron density at the active Ni sites. More importantly, the infrared spectra and isotope labeling-mass spectrometry methods were used to establish the source of hydrogen and unravel the reaction mechanism. It is suggested that the cleavages of B–H and O–H bonds are the initial steps of AB hydrolysis, which lead to the formation of intermediates M–H– (metal and electronegative H– from −BH3) and M–H+ (metal and electropositive H+ from H2O), respectively. The H2 molecule could form through three main paths as (1) two H atoms from −BH3, (2) two H atoms from H2O, and (3) one H atom from −BH3 and another from H2O. Results of density functional theory (DFT) calculations are consistent with the formation of electron-rich Ni sites in the NiCu, and the activation of H2O is a rate-limiting step (RLS). Redistribution of electrons in NiCu significantly enhances the adsorption of AB, the activation of H2O molecules, and the associative desorption of H adatoms as well, which effectively promote the cleavage of B–H and O–H bonds and release of H2. This work gives a systematic mechanistic study on photocatalytic AB hydrolysis involving multichannel electron-transfer pathways, which will provide a powerful guidance for the rational design of active catalysts for AB hydrolysis through multipronged effects.
研究领域:
催化化学
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材料科学
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理论计算
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DOI
高影响因子
FUEL PROCESSING TECHNOLOGY
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2023
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IF 7.5
Fa-Peng Wu,Yun-Peng Zhao,Zong-Pin Fu,Le-Le Qiu,Jian Xiao,Jian Li,Fang-Jing Liu,Jing-Pei Cao
Efficient transfer hydrogenolysis of benzyl phenyl ether (BPE) was accomplished over Ni 1.5 Cu 1.5 /Al 2 O 3 using isopropanol as hydrogen source . The characterization results demonstrated that the formation of NiCu alloy and electron transfer between Ni and Cu were responsible for the excellent catalytic performance. Isopropanol displayed better hydrogen-donating ability than other low-carbon alcohols because of its unique dehydrogenation pathway and small steric hindrance . The results of isotopic experiments elucidated that active hydrogen species for the C O bond cleavage originated from isopropanol rather than H 2 , while both isopropanol and H 2 were responsible for hydrogenation of phenol to cyclohexanol when reaction was conducted with mixed hydrogen sources. A mechanism study illustrated that transfer hydrogenolysis of BPE proceeded through direct cleavage of C O bond followed by phenol hydrogenation, in which the active hydrogen species were in the form of H + and H − .
研究领域:
催化化学
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材料科学
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DOI
高影响因子
CATALYSIS LETTERS
·
2020
·Vol. 151
·期 6
·1670-1682
·
IF 2.482
Zhu Tianhan,Song Hua,Li Feng,Chen Yanguang
A series of bimetallic Ni x Cu (10- x ) /SiO 2 (where x is the mass fraction of Ni and the total metal loading was fixed at 10 wt%.) catalysts with different Ni/Cu mass ratio are prepared and characterized by X-Ray diffraction (XRD), N 2 adsorption-desorption, inductively coupled plasma mass spectrometry (ICP-MS), H 2 temperature-programmed reduction (H 2 -TPR) and transmission electron microscope (TEM). The benzofuran (BF) hydrodeoxygenation (HDO) performance of as-prepared catalysts are evaluated in a fixed flow reactor. The results showed that the incorporation of Cu to Ni/SiO 2 catalyst can increase surface area of catalyst and improve the reducibility of nickel oxide species, which contributed to higher catalytic activity and total deoxygenated compounds yield. Moreover, the strong synergistic effect between Ni and Cu led to the formation of NiCu alloy at the Ni mass fraction of 5 wt% and thus induced smaller crystallite size and exposure of more active particles, which inevitably contributed to the improved HDO performance for Ni 5 Cu 5 /SiO 2 catalyst. At 300 °C, 3.0 MPa, MHSV=3.0 h −1 and H 2 /oil = 500(v/v), the total yield of deoxygenated products over Ni 5 Cu 5 /SiO 2 catalyst reached 86.0%, which is increased by 10.8% and 77.4% as compared to those of monometallic Ni/SiO 2 (75.2%) and Cu/SiO 2 catalysts (8.8%), respectively. Finally, a possible reaction network for HDO of BF on Ni 5 Cu 5 /SiO 2 catalyst was proposed. Graphic Abstract
研究领域:
催化化学
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能源化学
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DOI
高影响因子
JOURNAL OF SOLID STATE ELECTROCHEMISTRY
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2025
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IF 2.6
Qiao Yun-ze,Hua Yu,Wu Guang-xin,Shi Chen-yang,Huang Ying-de,Yang Wen-jie
Due to its excellent conductivity and corrosion resistance, NiCu alloy has been extensively studied and utilized by researchers. However, existing research primarily focuses on the corrosion rate, current efficiency, and aluminum product purity of inert anodes, with limited detailed analysis of the corrosion mechanism. This study investigates the corrosion behavior of NiCu alloy in a Na 3 AlF 6 -AlF 3 -Al 2 O 3 system using cyclic voltammetry, potentiodynamic polarization, X-ray diffraction, and scanning electron microscopy. Pure Ni, pure Cu, and an equiatomic NiCu alloy were selected as samples, and the corrosion resistance of the NiCu alloy was evaluated through electrolytic experiments. The results reveal that the corrosion resistance of NiCu alloy surpasses that of both Ni and Cu. A mixed oxide layer consisting of Cu 2 O, NiO, and NiAl 2 O 4 was formed on the surface of the NiCu alloy, effectively protecting the anode substrate while maintaining the stability of the electrolytic voltage. After electrolysis at a current density of 1 A/cm 2 for one hour, the thickness of the corrosion layer was measured to be 21.3 μm. Additionally, the presence of aluminum oxide was found to enhance the protection of the inert anode during electrolysis.
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高影响因子
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