Catalysts
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2022
·Vol. 12
·期 10
·1146
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IF 4.501
Jikang Yao,Yuanjie Xu,Hua Yang,Zhuangzhuang Ren,Lizhi Wu,Yu Tang
The partial oxidation of methane (POM) is a promising method for converting methane to syngas. The transition metal supported on boron nitride (BN) has recently been studied as part of a catalog of emerging catalysts. However, the chemical state of the metal supported on BN during methane reforming is still in debate. In this work, we report a rhodium catalyst on boron nitride (Rh/BN) for the POM, with exceptional activity and long-term stability at 600 °C for 230 h. The Rh/BN catalyst was investigated by X-ray diffraction, X-ray photoelectron spectroscopy, Raman spectroscopy, transmission electron microscopy, and diffuse reflectance infrared Fourier transformed spectroscopy (DRIFTS). As revealed by in situ DRIFTS, the infrared band (2020 cm−1) of the product molecule, CO, adsorbed on the Rh, as the probe confirms the metallic state of Rh during the POM reaction. In addition, the results of in situ DRIFTS indicate that the reactive gaseous environment would react with the catalyst to form B-OH and B-H, which synergistically boost the POM activity.Keywords:partial oxidation of methane;syngas;boron nitride;rhodium;DRIFTS
研究领域:
化学工程
·
催化科学
✓ 已验证
DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
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2023
·
IF 22.1
Rui Liu,Xianhua Zhang,Tao Liu,Xian Yao,Zhijian Zhao,Chunlei Pei,Jinlong Gong
The oxygen species over oxygen carriers determine the reaction performance in chemical looping partial oxidation of methane (CLPOM). This paper describes the dynamic migration and reaction of oxygen species over ceria-supported NiO oxygen carrier for CLPOM. At initial reaction stage, Ni-O species could be consumed rapidly and cause the full oxidation of methane to CO 2 . Afterwards, the active Ni-O-Ce species dominates the methane partial oxidation to promote the syngas yield. It is found that CO formation rate is linearly related with the content of oxygen species over Ni-O-Ce. Furthermore, the lattice oxygen from CeO 2 would migrate through the bulk to complement the consumed Ni-O-Ce oxygen species. Eventually, 5NiO/(40CeO 2 -Al 2 O 3 ) exhibit nearly three times as high as methane reaction rate of CeO 2 /Al 2 O 3 and two times as high as CO formation rate of 5NiO/Al 2 O 3 . This work provides the comprehensive understanding of transport and reaction mechanism of oxygen species for chemical looping processes.
研究领域:
化学工程
·
能源科学
✓ 已验证
产品关联
DOI
高影响因子
CHEMISTRY OF MATERIALS
·
2025
·
IF 7
Henglong Li,Pengheng Li,Min Lin,Xing Zhu
The design of oxygen carriers is essential for the chemical looping partial oxidation of methane (CL-POM) in syngas production. LaFeO3 is a promising oxygen storage material, but the impact of its morphology on the reaction characteristics and mechanisms in CL-POM remains unclear. Herein, we synthesized and characterized LaFeO3 samples with diverse morphologies (cube, porous microsphere, irregular nanoparticle, and polyhedron) to explore how morphology governs crystal plane exposure, oxygen vacancy formation, and oxygen migration. Results showed that cubic LaFeO3 not only achieved outstanding oxygen storage capacity (4.18 mmol/g), 2.5 times that of the other three samples combined (1.64 mmol/g), but also demonstrated superior methane reactivity with good low-temperature activity (initial reaction temperature of 500 °C) and the highest methane conversion (78.26% at 750 °C). This impressive performance is due to the synergy between oxygen vacancies and the (110) crystal plane, which optimizes oxygen release and enhances methane adsorption and dissociation. DFT calculations further confirmed that the (110) plane has lower energy barriers for reaction processes than the (100) plane, and more oxygen vacancies enhance reactivity and oxygen migration. This work underscores the pivotal role of LaFeO3 morphology in advancing the design of oxygen storage materials and a redox catalyst.
研究领域:
材料科学
·
能源化学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING SCIENCE
·
2023
·
IF 4.7
Xian Yao,Xianhua Zhang,Rui Liu,Chunlei Pei,Zhi-Jian Zhao,Jinlong Gong
The oxygen species in oxygen carriers directly influence the reaction performance in chemical looping processes. This paper describes the relationship between oxygen species and performance in chemical looping partial oxidation of methane (CLPOM) over LaNi x Ti 1- x O 3- δ ( x = 0, 0.25, 0.5, 0.75 and 1) perovskites . Due to the increase of Ti substitution, the predominate reaction during CLPOM gradually changes from complete oxidation to partial oxidation. Quasi in situ XPS characterization suggests that the relative concentration of nucleophilic lattice oxygen species for partial oxidation increases with Ti substitution, while the relative concentration of electrophilic adsorbed oxygen species for complete oxidation decreases. The moderate Ti substitution for LaNi 0.5 Ti 0.5 O 3- δ provides the suitable lattice oxygen activity for the methane partial oxidation. Moreover, LaNi 0.5 Ti 0.5 O 3- δ exhibits high cyclic stability in redox cycles. This work demonstrates that the regulation of oxygen species distribution and activity is feasible to tailor the reaction performance of oxygen carriers in chemical looping processes.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2025
·
IF 8.2
Wenxin Fu,Yige Guo,Jianqiu Zhu,Xiaomin Zhang,Linjuan Zhang,Yuefeng Song,Guoxiong Wang,Xinhe Bao
Coupling the partial oxidation of methane (POM) to the anode of solid oxide electrolysis cells (SOECs) can significantly decrease the open-circuit voltage and electrical energy consumption of the SOECs. However, developing advanced anode for SOEC to selectively convert CH4 to syngas still remains a great challenge. Herein, we find that Ce substitution at the A-site of La0.5Ce0.5Fe0.5Ni0.5O3−δ can effectively alter the chemical state and coordination environment of Ni with the generation of NiO particles, and the air activation could further regulate the oxygen vacancy concentration and decrease the size of NiO particles, which both contribute to the enhanced POM performance with CH4 conversion of 45.20% and CO selectivity of 92.67% at 650 °C. Moreover, the introduction of POM to the anode could remarkably decrease the electrical energy consumption for CO production from 3.64 kWh m–3 of conventional SOECs to 0.86 kWh m–3 of CH4-assisted SOECs. This study provides an effective strategy for improving the electrochemical performance of CO2 electrolysis in SOECs while simultaneously converting CH4 to syngas at the anode.
研究领域:
材料科学
·
能源工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Molecular Catalysis
·
2023
·
IF 4.6
Hua Yang,Zemin An,Yuanjie Xu,Lizhi Wu,Li Tan,Yu Tang
The restructuring of a catalyst under working conditions has been recognized as a critical factor that can significantly impact their performance in recent years. In this study, we investigate the behavior of a highly dispersed Ni supported on TiO 2 (P25) catalyst during the partial oxidation of methane (POM) to produce syngas. Our results reveal a distinct oscillation phenomenon in the catalyst's performance over time. The simultaneous oscillations of rapid deactivation and activation are observed, while the catalyst remains active for continuous POM reaction. Comprehensive characterizations suggest that this deactivation is not caused by traditional deactivation mechanisms with coke formation or Ni sintering. The formation of inactive NiTiO 3 results in catalyst deactivation, which is formed between Ni and TiO 2 support in the reductive atmosphere of POM products under high temperature due to strong metal-support interaction (SMSI). The simultaneous presence of oxidative and reductive atmospheres of the reactants and products in the POM reaction leads to the generation or demise of NiTiO 3 . The dynamic change of the Ni active sites during the in-situ reaction leads to the oscillation of the catalytic activity. This study sheds new light on the importance of SMSI in understanding the behavior of catalysts under working conditions.
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
危险品化学品经营许可证（带存储）