CATALYSIS LETTERS
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2020
·Vol. 151
·期 1
·194-211
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IF 2.482
Chen Xilong,Dong Yanzeng,Yu Xiaohang,Wang Zhiheng,Liu Yanyan,Liu Jiankun,Yao Songdong
Abstract Steric hindrance of methyl on reaction pathway of hydrodesulfurization in presence of quinoline was investigated over a NiMo/Al 2 O 3 catalyst at 4.0 MPa and 320 °C. The results show that steric hindrance of methyl changed the main pathway of HDS while presence of quinoline further exacerbated this transformation. Changes in inhibitory factor curve show that quinoline poisoning on DBT HDS is a relatively mild. When adjacent methyl is present, even at low concentration, the inhibitory factor of quinoline on 4,6-DMDBT HDS is still greater than 85%. At high levels, the inhibitory factor of quinoline on DDS pathway even exceeds 99%. Quinoline poisons HYD pathway of DBT HDS to a stable level in a short time (30 to 60 min). However, after 6 h of reaction, HYD pathway yield of 4,6-DMDBT HDS is still increasing. Quinoline simultaneously poisons HYD and DDS pathways of 4,6-DMDBT HDS to a stable level within 120 min, and then DDS pathway will continue to be poisoned, thereby increasing HYD pathway yield. Regardless of presence of adjacent methyl in sulfur-containing molecules, an increase in quinoline concentration will lead to an increase in HYD/DDS pathway yield ratio. Addition of quinoline inhibits conversion of hydrogenated intermediates to DDS products by poisoning C–S bond dissociation center (such as CUS active site) and leads to formation of deep hydrogenated products. Graphic Abstract
研究领域:
催化化学
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石油炼制工程
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环境化学
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产品关联
DOI
高影响因子
ENERGY & FUELS
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2018
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IF 3.024
Tingting Huang,Jingyao Chang,Shuisen He,Chenglong Wen,Yu Fan
This paper proposes a novel one-step hydrothermal polyoxometalate (POM) dispersion method for synthesizing NiMo/Al2O3 hydrodesulfurization (HDS) catalysts with high Ni/Mo atomic ratios. The proposed method disperses Mo12O30(μ2-OH)10H2[Ni(H2O)3]4 on the surface of Al2O3 under a hydrothermal environment, which promotes the formation of highly dispersed MoS2 slabs with increased stacking. The proximity between Ni and Mo in POM improves the decoration of MoS2 slabs by Ni, and the high Ni/Mo ratio of POM synthesized by the one-step method ensures that the corresponding catalyst possesses a high concentration of active NiMoS phases. The as-prepared POM-based NiMo/Al2O3 catalyst possesses much better activity in 4,6-dimethyldibenzothiophene HDS than its counterparts synthesized via the traditional incipient wetness impregnation method.
研究领域:
化学工程
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催化材料
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产品关联
DOI
高影响因子
CATALYSIS TODAY
·
2021
·
IF 6.766
Qiang Wei,Wenbin Huang,Xiaodong Liu,Anqi Li,Pengfei Zhang,Zhusong Xu,Zhiqing Yu,Xiaohan Wang,Haoran Liu,Yasong Zhou
A series of Re modified NiMo/Al 2 O 3 hydrodesulfurization (HDS) catalysts with different contents of Re 2 O 7 were successfully synthesized by stepwise impregnation method and co-impregnation method respectively. The effects of Re modification and impregnation methods on the physical-chemical properties of the prepared catalysts were determined by the characterization techniques such as XRD, N 2 physical adsorption-desorption, NH 3 -TPD, Py-FTIR and HRTEM. Finally, the effects of the Re modification and the impregnation methods on the catalytic activity and the HDS reaction route selectivity were evaluated using 4,6-dimethyldibenzothiophene (4,6-DMDBT) as a probe. The results show that the crystal morphologies and pore structures of the synthesized catalysts varied with the contents of Re 2 O 7 and the impregnation methods and the amounts of acid sites can be modulated by the incorporation of Re 2 O 7 and the impregnation methods. Moreover, Re modification was conducive to the formation of the “type II” Ni-Mo-S active phase by changing the morphology of the Ni promoted MoS 2 slabs. The HDS evaluation of 4,6-DMDBT results show that Re modification can effectively improve the 4,6-DMDBT conversions, DDS route selectivity and even 3,3′-dimethylcyclohexanebenzene (3,3′-DMCHB) selectivity in varying degrees, and compared with that of co-impregnation method, the Re modification by stepwise impregnation method exhibited a more prominent effect. In general, 1 wt% Re 2 O 7 content was the most favorable to the HDS reaction since excessive Re 2 O 7 content has very little promoting effect.
研究领域:
催化化学
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材料科学
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能源化工
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DOI
高影响因子
CATALYSIS TODAY
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2022
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IF 6.562
Xiaotong Meng,Yuchao Lyu,Junhao Liu,Wenshuo Ma,Yupeng Tian,Jianye Fu,Xinmei Liu
Spent catalysts from the hydrofining process are hazardous wastes, while their appropriate utilization can also bring enormous environmental and economic benefits. Herein, a chemical resurrection method was developed to resurrect and recycle the industrial spent NiMo/Al 2 O 3 hydrofining catalyst. The spent catalysts are calcined to remove the carbon deposit followed by the treatment with citric acid (CA) and ethylene glycol (EG). The results show that the calcination can also accelerate the aggregation and inerting of the active phase. However, the redispersion and reactivation of the inactive phases over the spent catalysts are realized through formation of metal complex with the citric acid, which weaken the interaction between Mo species and support. It increases reducibility of the Mo species and then improve the sulfurization degree of the resurrected catalyst. Besides, the average length of MoS 2 is reduced while the stacking number is increased. The ethylene glycol further regulates the reducibility of Ni and Mo species to promote the formation of NiMoS phase with high activity instead of Ni 3 S 2 . Consequently, the average length of the MoS 2 is reduced while the average stacking number of MoS 2 and content of the NiMoS phase are increased over the resurrected catalyst compared with the spent catalyst. It recovers the hydrodesulfurization activity of the resurrected catalyst to a level higher than that over the spent and industrially regenerated catalyst.
研究领域:
化学工程
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环境科学
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催化材料
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）