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285 results on '"Lin, Tiejun"'

22. Effect of Pr Promotion on Co-Based Catalysts for Fischer–Tropsch Synthesis to Olefins

Author

Zhou, Xuan, Wang, Xinxing, Li, Jiaqi, Zhang, Ranqing, Lin, Tiejun, An, Yunlei, and Zhong, Liangshu

Abstract

Fischer–Tropsch synthesis to olefins (FTO) from syngas with low CO2selectivity achieves great attention but still remains challenging. Herein, Pr-promoted metallic Co catalysts were applied to the FTO reaction, and the promotional effect was investigated in detail. All Pr-promoted catalysts displayed higher olefin selectivity and lower methane selectivity compared with the unpromoted Co-based catalysts. Moreover, the CO2selectivity was significantly suppressed, owing to the low intrinsic activity of metallic Co sites for the water–gas shift reaction (WGSR). The optimal Pr loading was found to be 10 wt %, which resulted in a high olefin selectivity of 44.1% and a low CO2selectivity of 1.1%. The structural characterization revealed that the addition of Pr altered the electronic state of Co species, leading to enhanced CO adsorption and a low H/C ratio on the catalyst surface. Furthermore, secondary hydrogenation activity was also inhibited by adding the Pr promoter, which is favorable for olefin production.

Published
2025
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24. Strong Metal‐Support Interactions: From Characterization, Manipulation to Application in Fischer‐Tropsch Synthesis and Atmospheric CO2 hydrogenation.

Author

Zhang, Wenzhe, Lin, Heyun, An, Yunlei, Lin, Tiejun, and Zhong, Liangshu

Subjects
HETEROGENEOUS catalysis, ENCAPSULATION (Catalysis), CHEMICAL reactions, METAL nanoparticles, METHANATION
Abstract

Strong metal‐support interactions (SMSI) featuring the formation of encapsulation overlayer around metal nanoparticles has drawn much attention in heterogeneous catalysis. Recent years, various novel SMSI phenomena have been observed and the nature of SMSI also has been revealed with the improvement of characterization techniques. Understanding the SMSI effect could deepen the insight into the structure‐activity relationship of metal‐supported catalysts, and rationally guide the design of special metal‐interface sites to manipulate catalytic behavior in chemical reaction. In this review, the research progress of SMSI and its application in heterogeneous COx hydrogenation are briefly surveyed, with emphasis on the advanced characterization, manipulation strategy and specific role of SMSI in Fischer‐Tropsch synthesis process, CO2 methanation and Reverse Water Gas Shift reaction. The current challenges and perspectives for the development of SMSI are also discussed. [ABSTRACT FROM AUTHOR]

Published
2024
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32. Regulating crystal phase of TiO2to enhance catalytic activity of Ni/TiO2for solar-driven dry reforming of methane

Author

HE, Zhanjun, GONG, Kun, DAI, Yuanyuan, NIU, Qiang, LIN, Tiejun, and ZHONG, Liangshu

Abstract

Ni/TiO2catalyst is widely employed for photo-driven DRM reaction while the influence of crystal structure of TiO2remains unclear. In this work, the rutile/anatase ratio in supports was successfully controlled by varying the calcination temperature of anatase-TiO2. Structural characterizations revealed that a distinct TiOxcoating on the Ni nanoparticles (NPs) was evident for Ni/TiO2-700 catalyst due to strong metal-support interaction. It is observed that the TiOxoverlayer gradually disappeared as the ratio of rutile/anatase increased, thereby enhancing the exposure of Ni active sites. The exposed Ni sites enhanced visible light absorption and boosted the dissociation capability of CH4, which led to the much elevated catalytic activity for Ni/ TiO2-950 in which rutile dominated. Therefore, the catalytic activity of solar-driven DRM reaction was significantly influenced by the rutile/anatase ratio. Ni/TiO2-950, characterized by a predominant rutile phase, exhibited the highest DRM reactivity, with remarkable H2and CO production rates reaching as high as 87.4 and 220.2 mmol/(g·h), respectively. These rates were approximately 257 and 130 times higher, respectively, compared to those obtained on Ni/TiO2-700 with anatase. This study suggests that the optimization of crystal structure of TiO2support can effectively enhance the performance of photothermal DRM reaction.

Published
2024
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35. Engineering ZrO2–Ru interface to boost Fischer-Tropsch synthesis to olefins.

Author

Yu, Hailing, Wang, Caiqi, Xin, Xin, Wei, Yao, Li, Shenggang, An, Yunlei, Sun, Fanfei, Lin, Tiejun, and Zhong, Liangshu

Subjects
RUTHENIUM catalysts, FISCHER-Tropsch process, HETEROGENEOUS catalysis, ACTIVATION energy, INTERFACIAL reactions, CATALYST synthesis
Abstract

Understanding the structures and reaction mechanisms of interfacial active sites in the Fisher-Tropsch synthesis reaction is highly desirable but challenging. Herein, we show that the ZrO2-Ru interface could be engineered by loading the ZrO2 promoter onto silica-supported Ru nanoparticles (ZrRu/SiO2), achieving 7.6 times higher intrinsic activity and ~45% reduction in the apparent activation energy compared with the unpromoted Ru/SiO2 catalyst. Various characterizations and theoretical calculations reveal that the highly dispersed ZrO2 promoter strongly binds the Ru nanoparticles to form the Zr-O-Ru interfacial structure, which strengthens the hydrogen spillover effect and serves as a reservoir for active H species by forming Zr-OH* species. In particular, the formation of the Zr-O-Ru interface and presence of the hydroxyl species alter the H-assisted CO dissociation route from the formyl (HCO*) pathway to the hydroxy-methylidyne (COH*) pathway, significantly lowering the energy barrier of rate-limiting CO dissociation step and greatly increasing the reactivity. This investigation deepens our understanding of the metal-promoter interaction, and provides an effective strategy to design efficient industrial Fisher-Tropsch synthesis catalysts. Understanding the structures of interfacial active sites is crucial in heterogeneous catalysis. Here the authors demonstrate that a ZrO2-Ru interface site significantly enhances reactivity in the Fischer-Tropsch to olefins process by altering the H-assisted CO dissociation route due to the presence of hydroxy species associated with Zr-OH*. [ABSTRACT FROM AUTHOR]

Published
2024
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49. Recent Advances in the Conversion of Methane to Syngas and Chemicals via Photocatalysis.

Author

Li, Ruitao, Zheng, Yihan, Gong, Kun, He, Zhanjun, Dai, Yuanyuan, Niu, Qiang, Lin, Tiejun, and Zhong, Liangshu

Subjects
SYNTHESIS gas, PHOTOCATALYSIS, SHALE gas, SOLAR energy conversion, NATURAL gas, PHOTOCATALYTIC oxidation, OIL shales
Abstract

As a primary constituent of natural gas and shale gas, direct conversion of methane has attracted significant attention due to its potential to reduce energy consumption and CO2 emissions. Compared with thermal catalysis, photocatalysis has the capacity to transcend thermodynamic constraint and enable the conversion of sustainable solar energy into chemical energy under mild reaction condition, which contributes to optimize the utilization of methane. In this review, we undertake a comparative analysis of various strategies for photocatalytic methane conversion to syngas and chemicals, including photocatalytic reforming of methane, photocatalytic partial oxidation of methane and photocatalytic coupling of methane. The distinct reaction systems with corresponding catalysts and underlying mechanisms are expounded in detail to foster a profound comprehension of solar‐driven methane conversion. Finally, the challenges and prospectives in photocatalytic methane conversion are discussed. [ABSTRACT FROM AUTHOR]

Published
2024
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