Molecular Catalysis
·
2023
·
IF 4.6
Jian Xue,Da Wang,Xingjuan Li,Guangci Li,Zhong Wang,Yuanshuai Liu,Xuebing Li
A tandem strategy of “mild preoxidation-hydrogenolysis” was proposed for the efficient depolymerization of lignin. Firstly, a mild oxidation system was constructed with H 2 O 2 as the green oxidant and NaOH/Fe 2 (SO 4 ) 3 /CuO as the catalyst to pretreat lignin; then NiMoS catalyst was used for the further hydrogenolysis of the pretreated lignin. The reaction results showed that the strategy could achieve efficient lignin depolymerization. Under optimal conditions, the lignin liquefaction degree reached 91.1 wt.% and the monomer yield reached 20.6 wt.%. The structural analysis of the recovered lignin showed that the mild oxidation pretreatment could initially break the linkage bonds within the lignin molecule and get some large fragment molecules. Meanwhile, it also made the hydroxyl group in the C α position of the β-O-4 bond oxidized to carbonyl group, thus reducing the dissociation energy of the β-O-4 bond.
研究领域:
化学工程
·
生物质能
✓ 已验证
产品关联
DOI
高影响因子
MICROPOROUS AND MESOPOROUS MATERIALS
·
2022
·
IF 5.876
Hao Zhang,Guang-Ren Qian,Hong Liu
Alumina composites containing microporous ZSM-5 (Z-5) and mesoporous ZSM-5 (MZ-5), corresponding to x ZA and x MZA, were developed by incorporating Z-5 and MZ-5 into γ - Al 2 O 3 , respectively. The two series of NiMoS/ x MZA and NiMoS/ x ZA catalysts were prepared with these two composites as supports, respectively, and were used for the simultaneous hydrodesulfurization (HDS) of thiophene (T) and benzothiophene (BT). The results show that NiMoS/ x MZA series catalysts exhibit higher HDS activity than that of NiMoS/ x ZA and NiMoS/γ-Al 2 O 3 , and the HDS activity of NiMoS/ x MZA catalysts increases with the increase of MZ-5. The high HDS activity can be mainly attributed to the synergistic effects of the efficient diffusing pore channels, high dispersion of type II NiMoS phases, suitable acidity, and moderate Mo-support interaction. Moreover, the product distribution of HDS shows that the NiMoS/ x MZA catalysts possess the dominant direct desulfurization (DDS) selectivity and the selectivity increases with the increase of MZ-5 content due to more corner sites and suitable Brønsted (B) acid sites, whereas the NiMoS/ x ZA catalysts perform more excellent hydrogenation (HYD) selectivity, and the selectivity increases with the increase of Z-5 content because of the existence of more edge sites. Based on this, the possible reaction network for T and BT hydrodesulfurization over the catalysts are proposed.
研究领域:
催化化学
·
能源化工
✓ 已验证
DOI
高影响因子
FUEL PROCESSING TECHNOLOGY
·
2021
·
IF 7.033
Antony Rajendran,Tian-You Cui,Hong-Xia Fan,Meng-Yu Wang,Wen-Ying Li
A straightforward hydrothermal synthesis of NiMoS active phases loaded on SBA-15 was attempted. We initially prepared a catalyst by impregnating metal precursors sequentially onto SBA-15 and the subsequent hydrothermal treatment with sublimed sulfur. To obtain the one-pot catalyst, we performed the hydrothermal treatment of a mechanical mixture containing metal precursors, sublimed sulfur, and SBA-15. The catalysts were characterized by powder X-ray diffraction, Raman spectroscopy, X-ray photoelectron spectroscopy, N 2 adsorption-desorption study, and high-resolution transmission emission spectroscopy . Compared to impregnation-assisted synthesis, the one-pot synthesis promoted the generation of dispersed shorter MoS 2 slabs with desirable average stacking number, i.e., increased number of edge and rim sites. Therefore, the one-pot catalyst enabled the ultra-deep sulfur removal (~100%) in the dibenzothiophene hydrodesulfurization . Unlike Ni(acac) 2 , the utilization of Ni(NO 3 ) 2 inhibits the sulfidation of molybdenum and the dispersion of MoS 2 layers, decreasing the hydrodesulfurization activity. The one-pot catalyst was able to achieve ~80% sulfur removal even after six consecutive catalytic runs under batch reactor conditions (320 °C, 6 MPa (H 2 ), 500 ppmw S, 100 mg (m cat )) due to the persistent stability of NiMoS active phases.
研究领域:
化学工程
·
催化材料科学
✓ 已验证
产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2024
·
IF 8.1
Fei Fan,Shiyu Han,Ying Li,Lu Qi,Jie Kang,Zhiping Chen,Chang Tian,DeChao Wang,Wenwu Zhou
The microenvironments including the surface hydroxyls , the oxygen vacancies , and the d-band center of hierarchical TS-1 zeolite pickled by hydrochloric acid were regulated by ZrO 2 , the effect of ZrO 2 on the physicochemical properties and the catalytic performances of the corresponding NiMoS supported catalysts were studied. The experimental and theoretical calculation results show that the d-band center, the surface hydroxyl groups , and the oxygen vacancies were regulated after incorporation of ZrO 2 . Resulting in the modulated acidity of the support and the metal support interaction of the catalysts, further promoting the formation of type-II NiMoS active phases. The catalytic performance evaluations show that catalyst NiMo/1-ZAT exhibits the superior HDS performance, kinetic study further demonstrated that the enhanced catalytic activity was mainly contributed by the improved direct desulfurization activity generated from the moderate support acidity, suitable MSI, highest sulfidation degrees, most type-II NiMoS active phase and highest activity of individual active sites.
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
·
2022
·
IF 24.319
Shuisen He,Tingting Huang,Yu Fan
Novel alumina-supported Ni-Mo hydrodesulfurization (HDS) catalysts were prepared via assembly of Mo and Al precursors induced by tetradecylamine (TDA). Compared with conventional impregnation, this assembly method improves Mo dispersion, weakens metal-support interactions, enhances Ni modification at MoS 2 edge sites, and produces more NiMoS phases on Al 2 O 3 . The optimal NiMoS microstructure was obtained by modulating the TDA/Mo ratio in the assembly. A microstructure-activity correlation indicated that the S vacancies at the NiMoS corner sites favored σ-adsorption and direct desulfurization of 4,6-dimethylbenzothiophene (4,6-DMDBT), and those at the NiMoS edge sites promoted C-S breaking in hydrogenated derivatives of 4,6-DMDBT. Among these catalysts, NiTMo-2.0/Al 2 O 3 , which had the most corner and edge S vacancies, exhibited the highest reaction rate constant of 5.89 × 10 −7 mol·g −1 ·s −1 and the highest desulfurization ratio of 99.5% in HDS of 4,6-DMDBT.
研究领域:
催化化学
·
能源化工
✓ 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）