Article
Environmental Sciences
Dali Hou, Fengming Gong, Hongming Tang, Jianchun Guo, Xianyu Qiang, Lei Sun
Summary: This study characterized the clay minerals in shale using sodium-based montmorillonite and investigated the adsorption law of CH4 in clay minerals, which is significant for shale gas extraction. Additionally, the competitive adsorption law of CH4 and CO2 was studied, and the theoretical sequestration of CO2 in shale clay minerals was predicted, providing reference values for CO2 burial in shale and carbon neutrality achievement. This study simulated the adsorption behavior of CH4 in sodium-based montmorillonite and the competitive adsorption of CH4 and CO2. The results showed the effects of temperature, pressure, and pore size on adsorption capacity and the competitive adsorption ratio between CO2 and CH4.
Article
Energy & Fuels
Guenther Glatz, Saad Alafnan, Raoof Gholami, Arshad Raza, Mohamed Mahmoud, Khaled Al-Azani, Abeeb Awotunde
Summary: This study investigates the adsorption characteristics of shale under various pressure and temperature conditions and evaluates the predictive power of different theoretical adsorption models. The results suggest that the Langmuir, Toth, and Langmuir-Freundlich models are suitable for single component adsorption, while the Toth and LRC models are capable of capturing acceptable binary adsorption behavior.
Article
Energy & Fuels
Li Zhao, Ni Guanhua, Wen Yongzan, Jiang Hehe, Zhang Xiangfei, Wang Gang, Wang Zhenyang
Summary: The competitive adsorption mechanism of CH4 and CO2 was studied, revealing that CO2 adsorption is dominated by electrostatic force and is enhanced by hydrogen bonds with coal. Adsorption mainly occurs in the middle orbit, with more adsorption sites for CO2 in the low and middle orbit compared to CH4. CO2 molecules can enter ultrafine pores, resulting in larger accessible solvent pore volume and surface area compared to CH4.
Article
Energy & Fuels
Jinzhang Jia, Yumo Wu, Dan Zhao, Bin Li, Dongming Wang, Fengxiao Wang
Summary: To understand the mechanism of gas adsorption by different functional groups in coal, a slit-pore model and modified fragment model were developed using Materials Studio software. The study revealed the adsorption characteristics and performance of seven different functional groups on CH4/CO2/N2 gases. The results showed that the electrophilic and nucleophilic abilities of the functional groups varied, and the adsorption capacity was influenced by both gas properties and functional group structure.
Article
Thermodynamics
Chao Qin, Yongdong Jiang, Shuangying Zuo, Shiwan Chen, Siyou Xiao, Zhengjie Liu
Summary: This study investigates the adsorption kinetics behaviors of CH4 and CO2 on shale affected by exposure to supercritical CO2, finding a decrease in adsorption rates and different rates between the two gases. The study suggests three stages for the CS-ESGR project: Fracturing-Recovery, Replacement-Recovery-Sequestration, and Replacement-Sequestration-Recovery, providing valuable insights for future optimization design.
Article
Energy & Fuels
Jian Wu, Pengyu Huang, Federico Maggi, Luming Shen
Summary: CO2-enhanced gas recovery is a promising method for improving shale gas production and achieving CO2 storage. The displacement efficiency of CO2-CH4 increases with CO2 injection pressure but decreases with reservoir depletion pressure. CO2 injection induces expansion of the original CH4-saturated kerogen, leading to reduced permeability.
Article
Chemistry, Physical
Kawthar Adewumi Babatunde, Berihun Mamo Negash, Muhammed Rashik Mojid, Tigabwa Y. Ahmed, Shiferaw Regassa Jufar
Summary: Molecular simulation is widely used in adsorption studies, but realistic modeling and preparation of shale remains a challenge. Existing studies often use single components to represent shale surfaces, lacking the heterogeneity and mineral diversity of actual shale surfaces. The proposed molecular shale model exhibits higher adsorption capacity and surface area, providing a more accurate understanding of adsorption behaviors.
APPLIED SURFACE SCIENCE
(2021)
Article
Engineering, Environmental
Fen Yue, Zeqin Chen, Xiaoqiang Liu, Zhiyu Xue, Xue Yang, Meijun Li, Mengmeng He, Ying Xue
Summary: The study investigates the competitive adsorption behaviors of shale gas and CO2 in shale, with a focus on the influences of geological depth, water content, and CO2 mole fraction. Results show that the enrichment region of pure CH4 is around 2600 m in orthoclase slit, and CO2 injection at depths of 2000-3200 m yields high methane production. Additionally, shallow geological depths of 200-400 m are beneficial for CO2 sequestration.
CHEMICAL ENGINEERING JOURNAL
(2022)
Article
Thermodynamics
Jian Wu, Luming Shen, Pengyu Huang, Yixiang Gan
Summary: CO2-enhanced gas recovery (EGR) is a promising technology that can sequestrate CO2 and enhance CH4 recovery in shale reservoirs. This study investigates the selective adsorption and transport of CO2-CH4 mixture in kerogen slit nanopores using molecular dynamics. It is found that the gas mixture velocity decreases logarithmically with increasing CO2 molar ratio, and the CO2/CH4 adsorption and transport selectivities are generally greater than one. These findings provide insights into the CO2-EGR in shale's organic matrix and highlight the importance of considering the selective transport of CO2-CH4 mixture in large-scale simulations.
Article
Energy & Fuels
Jingyue Sun, Zherui Chen, Xi Wang, Yue Zhang, Yan Qin, Cong Chen, Weizhong Li, Wenning Zhou
Summary: Studying the initial period of CO2-CH4 displacement behavior is crucial for understanding CO2-enhanced shale gas recovery technology. A CO2-CH4 displacement model was developed based on a heterogeneous surface pore, and molecular dynamics simulations were conducted to investigate the effects of depressurization exploitation and injection pressure on displacement behavior. The study found that the displacement process starts with CH4 reverse flow, followed by the injection pressure action stage and positive displacement stage. The extent of CH4 reverse flow significantly affects the system development process and final displacement efficiency. It is important to decrease reservoir pressure during depressurization exploitation and consider displacement efficiency, reservoir safety, and economic cost when selecting CO2 injection pressure. Furthermore, CO2 occupies adsorption sites near graphene faster, while CH4 desorption is faster near montmorillonite (MMT), emphasizing the importance of considering the characteristics of different materials in the displacement process.
Article
Energy & Fuels
Qi Liao, Junping Zhou, Xuefu Xian, Kang Yang, Chengpeng Zhang, Zhiqiang Dong, Hong Yin
Summary: This study measured the adsorption of pure and binary CO2 and CH4 in shale using the volumetric method. The results showed that CO2 was preferentially adsorbed in shale, and the adsorption amount of binary CO2/CH4 increased with the increase of CO2 composition. The selectivity factor of CO2 over CH4 was closely related to pressure and CO2/CH4 concentration, and the injection strategy of CO2 can be optimized based on the results.
Article
Engineering, Environmental
Jingyue Sun, Cong Chen, Wenfeng Hu, Jingwei Cui, Lanlan Jiang, Yu Liu, Yuechao Zhao, Weizhong Li, Yongchen Song
Summary: The CO2 sequestration and enhanced gas recovery (CS-EGR) technology is effective in alleviating the greenhouse effect and energy crisis, especially in understanding the competitive adsorption behavior of CO2 and CH4 in shale matrix. The graphene-MMT heterogeneous surface pore model plays a vital role in studying the competitive adsorption features.
CHEMICAL ENGINEERING JOURNAL
(2021)
Article
Energy & Fuels
Humera Ansari, Shuwei Gong, J. P. Martin Trusler, Geoffrey Maitland, Ronny Pini
Summary: This study presents a hybrid pore-scale model for gas adsorption in shale, using surrogate surfaces to simulate the behavior. The reliability of the model is verified through comparisons with experimental data. The proposed model can reduce the experimental burden and has general applicability.
Article
Chemistry, Multidisciplinary
Xidong Du, Dongdong Pang, Yuan Zhao, Zhenkun Hou, Hanglong Wang, Yugang Cheng
Summary: This study examines the adsorption characteristics of CO2, N-2, and CH4 on kaolinite clay and investigates the effects of temperature, separation coefficients, and spontaneity on the adsorption behavior.
ARABIAN JOURNAL OF CHEMISTRY
(2022)
Article
Energy & Fuels
Reyna Ojeda-Lopez, Enrique Vilarrasa-Garcia, Diana C. S. Azevedo, Carlos Felipe, Juan A. Cecilia, Enrique Rodriguez-Castellon
Summary: The CO2 selectivity in CO2:CH(4) and CO2:N-2 mixtures has been studied in carbon materials with different morphologies and properties. The results show that carbon microfibers have higher CO2 adsorption capacity and selectivity, especially at higher pressures. They also exhibit better CO2 selectivity in CO2:CH4 mixtures. These findings suggest that carbon microfibers are a promising material for CO2 capture and separation.
Article
Chemistry, Physical
Eric T. Baxter, Jun Zhang, Shuai Tan, Manh-Thuong Nguyen, Difan Zhang, Qinqin Yuan, Wenjin Cao, Xue-Bin Wang, Venkateshkumar Prabhakaran, Vassiliki-Alexandra Glezakou, Grant E. Johnson
Summary: This study investigates the effects of ionic liquid clusters on ion adsorption and separation, and demonstrates that different sized and stoichiometric ionic liquid clusters can be used to improve the efficiency of electrochemical separations.
CHEMISTRY OF MATERIALS
(2022)
Article
Chemistry, Physical
Guang-Jie Xia, Mal-Soon Lee, Vassiliki-Alexandra Glezakou, Roger Rousseau, Yang-Gang Wang
Summary: Interstitial Ti defects and O vacancies are common in TiO2-x catalytic support materials and play significant roles in catalytic performance. Au clusters on TiO2-x surface can induce outward diffusion and surface segregation of interstitial Ti defects, promoting the regrowth of TiO2 islands. The interaction between different metal clusters and interstitial Ti affects the diffusion rates and provides insights into reaction mechanisms.
Article
Chemistry, Multidisciplinary
Loukas Kollias, Difan Zhang, Sarah I. Allec, Manh-Thuong Nguyen, Mal-Soon Lee, David C. Cantu, Roger Rousseau, Vassiliki-Alexandra Glezakou
Summary: Increasing atmospheric concentrations of greenhouse gases due to industrial activity have led to concerning levels of global warming. Reducing carbon dioxide (CO2) emissions is crucial in mitigating further warming, and CO2 capture solvent systems are currently the only technology capable of achieving this on an industrial scale. Designing these solvents for specific applications is a complex task that requires optimizing both thermodynamic and transport properties. Atomic scale modeling can be an effective tool in studying the energetics and transport properties of these chemically complex solvents.
Article
Chemistry, Multidisciplinary
Loukas Kollias, Roger Rousseau, Vassiliki-Alexandra Glezakou, Matteo Salvalaglio
Summary: In this study, the collective assembly of building units during the early stages of metal-organic framework (MOF) nucleation was investigated using large-scale molecular dynamics simulations. The choice of solvent, introduction of ions, and relative populations of MOF building unit isomers were found to greatly influence the cluster formation process, leading to variations in shape, size, nucleation and growth rates, crystallinity, and order. Graph theory analysis revealed that only a few molecular descriptors were needed to understand MOF self-assembly and these descriptors can be experimentally observed. This approach provides valuable insights into the complex processes of MOF synthesis and scale-up.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)
Article
Chemistry, Physical
Malgorzata Zofia Makos, Pradeep Kumar Gurunathan, Simone Raugei, Karol Kowalski, Vassiliki-Alexandra Glezakou, Roger Rousseau
Summary: The study highlights the importance of computational chemistry methods in predicting thermodynamic quantities, especially in understanding the role of solvents and reactive environments in catalysis and electrocatalysis. By utilizing various theoretical methods and models, and benchmarking against experimental results, accurate predictions can be obtained.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2022)
Editorial Material
Chemistry, Multidisciplinary
Vassiliki-Alexandra Glezakou, Roger Rousseau, Tong Lin
Article
Physics, Condensed Matter
Michael Gottschalk, Mal-Soon Lee, Eric Goodwin, Camille Mikolas, Thomas Chasapis, Duck Young Chung, Mercouri G. Kanatzidis, Subhendra D. Mahanti, Stuart Tessmer
Summary: Using scanning tunneling spectroscopy, the effects of nitrogen gas exposure on the electronic density of states of Bi2Se3 were investigated. Nitrogen gas molecules were observed to physisorb near Se vacancies, resulting in a saturation of the exposure effect after approximately 50 min. Density functional theory calculations and molecular dynamics simulations support the dissociative adsorption of N2 molecules and their strong binding to Se vacancies, which modifies the position of the Fermi energy relative to the Dirac point.
SOLID STATE COMMUNICATIONS
(2023)
Review
Chemistry, Multidisciplinary
Manh-Thuong Nguyen, Carlos A. Fernandez, Mostofa Haider, Kung-Hui Chu, Guoqing Jian, Somayeh Nassiri, Difan Zhang, Roger Rousseau, Vassiliki-Alexandra Glezakou
Summary: Cement and concrete are essential materials for constructing durable habitats and infrastructure. However, concrete cracking leads to expensive repairs and contributes to climate change. Therefore, the development of more durable cementitious materials with self-healing capabilities is urgently needed. This review presents five different strategies to achieve self-healing in cement-based materials and discusses the self-healing agents and mechanisms involved.
Article
Chemistry, Physical
Runze Ma, Christopher R. O'Connor, Gregory Collinge, Sarah I. Allec, Mal-Soon Lee, Zdenek Dohnalek
Summary: The dynamics of acetic acid on anatase TiO2(101) were investigated using scanning tunneling microscopy experiments and density functional theory calculations. The study showed the simultaneous diffusion of bidentate acetate and a bridging hydroxyl, as well as the transient formation of molecular monodentate acetic acid. The diffusion rate was found to be strongly dependent on the position of hydroxyl and adjacent acetate(s). A three-step diffusion process involving acetate and hydroxyl recombination, acetic acid rotation, and acetic acid dissociation was proposed. This study provides insights into the importance of bidentate acetate dynamics in the formation of monodentate species, which drive selective ketonization.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2023)
Article
Chemistry, Multidisciplinary
Linxiao Chen, Sarah I. Allec, Manh-Thuong Nguyen, Libor Kovarik, Adam S. Hoffman, Jiyun Hong, Debora Meira, Honghong Shi, Simon R. Bare, Vassiliki-Alexandra Glezakou, Roger Rousseau, Janos Szanyi
Summary: Research interest in single-atom catalysts (SACs) has been increasing, however, the lack of understanding of their dynamic behaviors during applications hinders catalyst development and mechanistic understanding. This study reports on the evolution of active sites over a Pd/TiO2-anatase SAC in the reverse water-gas shift (rWGS) reaction. The insights gained about SAC dynamics and the structure-function relationship are valuable for mechanistic understanding and catalyst design.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Chemistry, Applied
Christopher R. O'Connor, Runze Ma, Gregory Collinge, Mal-Soon Lee, Greg A. Kimmel, Zdenek Dohnalek
Summary: In this study, the adsorption and reaction of acetic acid on anatase TiO2(101) were investigated using various techniques. It was found that acetic acid can form two intermediates: dissociated, bidentate acetate and molecular, monodentate acetic acid. The presence of both intermediates was observed at low temperatures, while only the bidentate acetate was observed at high temperatures. This research provides important insights into the stability and reactivity of carboxylic acid surface-bound intermediates, which play a role in biomass upgrading via ketonization reactions.
TOPICS IN CATALYSIS
(2023)
Article
Chemistry, Physical
Jinshu Tian, Gregory Collinge, Simuck F. F. Yuk, Jindong Lin, Vassiliki-Alexandra Glezakou, Mal-Soon Lee, Yong Wang, Roger Rousseau
Summary: Through density functional theory calculations, in situ Raman characterization, and microkinetic modeling, it is found that dimerized di-coordinated boron sites are the active species for O-2 activation and peroxy-like structures are responsible for propane activation. The formation of adsorbed C3H7* radicals was found to be the main rate-controlling step. These findings provide significant insights into the mechanisms of oxidative dehydrogenation of propane on boron-based catalysts.
Article
Chemistry, Physical
Vanessa Lebarbier Dagle, Gregory Collinge, Mohammed Rahmana, Austin Winkelman, Wenda Hu, Jian Zhi Hu, Libor Kovarik, Mark Engelhard, Jennifer Jocz, Yong Wang, Mal-Soon Lee, Vassiliki-Alexandra Glezakou, Debmalya Ray, Roger Rousseau, Robert Dagle
Summary: This study reports on a Cu/ZrO2/SBA-16 catalyst with remarkable olefins selectivity and enhanced stability compared to the Ag/ZrO2/SBA-16 catalyst. Replacing Ag with Cu shifts the reaction pathway of crotonaldehyde hydrogenation, leading to the formation of butyraldehyde. Experimental and computational tools were used to verify the performance and stability advantage of the Cu/ZrO2/SBA-16 catalyst.
APPLIED CATALYSIS B-ENVIRONMENTAL
(2023)
Article
Chemistry, Multidisciplinary
Oliva M. M. Primera-Pedrozo, Shuai Tan, Difan Zhang, Brian T. T. O'Callahan, Wenjin Cao, Eric T. T. Baxter, Xue-Bin Wang, Patrick Z. Z. El-Khoury, Venkateshkumar Prabhakaran, Vassiliki-Alexandra Glezakou, Grant E. E. Johnson
Summary: This study synthesized Keggin POMs with both tungsten and vanadium atoms and used ion soft landing to deliver these POMs to different self-assembled monolayer surfaces on gold. The interactions between POMs and supports, as well as POMs and neighboring POMs, were characterized using various spectroscopic techniques. The results showed that surface functional groups and nanoscale heterogeneity can modulate the observed spectroscopic signatures, and POM-POM interactions also affect the spectral shifts.
