Article
Chemistry, Applied
Jiale Zhu, Siyan Yan, Yuan Qian, Xuedong Zhu, Fan Yang
Summary: A novel fluffy-ball like ZSM-5 zeolite was synthesized by biphasic hydrothermal method and exhibited improved physicochemical properties and catalytic performance in hexane cracking reaction. The fluffy-ball like ZSM-5 possessed uniform morphology and higher pore volumes, leading to enhanced diffusion efficiency and suppressed side reactions. The catalyst demonstrated higher selectivities to light olefins and improved stability compared to conventional ZSM-5.
MICROPOROUS AND MESOPOROUS MATERIALS
(2023)
Article
Chemistry, Physical
Chenggong Song, Xu Hou, Hao Zhou, Huimin Qiao, Li Yin, Jing Huang, Enxian Yuan, Tingting Cui
Summary: Plastic waste management and disposal has become a significant environmental concern. This study focuses on the use of catalysts, specifically introducing mesopores into HZSM-5 zeolites, to enhance catalytic activity and decrease the degradation temperature of plastic waste. The results demonstrate that mesopore volume has a positive impact on degradation efficiency.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2023)
Article
Chemistry, Organic
E. E. Vorobyeva, D. A. Sladkovskiy, A. I. Lysikov, E. V. Parkhomchuk
Summary: The paper introduced the preparation of two series of nanosized ZSM-5 zeolite crystals with a Si/Al molar ratio of 70 to 144 by a template method. The study focused on the distinctive characteristics of the catalysts, including intercrystalline macroporosity and random architecture of transport channels, achieved through the use of high-molecular-weight polystyrene particles as templates. The catalytic properties of the samples in n-hexane cracking reaction were tested and compared in terms of conversion degree and selectivity for different products.
PETROLEUM CHEMISTRY
(2021)
Article
Nanoscience & Nanotechnology
Bastian Reiprich, Karolina A. Tarach, Kamila Pyra, Gabriela Grzybek, Kinga Gora-Marek
Summary: Layer-like FAU-type zeolite Y was successfully synthesized by an organosilane-assisted low-temperature hydrothermal method, and its catalytic activity in LDPE cracking was verified. The structure and properties of zeolite Y were analyzed using various techniques, and its catalytic performance and coking were evaluated through experiments on catalyst selectivity and coke residue.
ACS APPLIED MATERIALS & INTERFACES
(2022)
Article
Chemistry, Applied
Hagos Birhane Asfha, Ashenafi Hailu Berta, Nayoung Kang, Danim Yun, Jaedeuk Park, Yong-Ki Park, Kiwoong Kim
Summary: In this study, a reaction mechanism of light straight run naphtha cracking over micro-spherical catalyst containing HZSM-5 was systematically investigated. The results showed that light paraffins and olefins were the primary products, and oligomerization and β-scission cracking dominated the secondary reactions. Experiments on single hydrocarbon feeds indicated that BTX formation proceeded via the formation of cycloalkanes and cyclo-olefinic intermediates. Temperature and space time influenced the product selectivity, with propylene selectivity increasing at lower temperatures and ethylene selectivity increasing at higher temperatures.
Article
Chemistry, Multidisciplinary
Maryam Ghazimoradi, Saeed Soltanali, Hamid Karami, Hamid Ghassabzadeh, Javad Bakhtiari
Summary: This study investigated the influence of different ZSM-5 composite materials on the n-hexane catalytic cracking process. The A2 catalyst, with a combination of γ-alumina and ZSM-5, showed the highest conversion, propylene selectivity, yield of light olefins, and propylene to ethylene ratio. The use of γ-alumina improved the catalyst's hydrothermal stability, resistance to deactivation, acidic properties, and mesoporosity.
Article
Chemistry, Multidisciplinary
Jiale Zhu, Fan Yang, Siyan Yan, Haidan Wu, Xuedong Zhu
Summary: In this study, core-shell structure catalysts with different shell thicknesses were fabricated using hydrothermal coating. Multiple characterization technologies were employed to analyze the physicochemical properties of the catalysts. It was found that controlling the shell thickness to 150 nm resulted in the best performance, with higher olefins yields and improved catalyst lifetime.
Article
Engineering, Chemical
Qianqian Yu, Zhongdong Zhang, Zhaoqian Zhang, Zhiguo Sun, Xionghou Gao, Hui Wang
Summary: Nickel-modified IM-5 zeolite was used to improve the performance of catalytic cracking and enhance the selectivity of light olefins. The introduction of nickel modulated the acidity of IM-5 zeolite and increased the amount of Lewis acid sites, resulting in higher olefin selectivity, especially for ethylene, in n-hexane cracking reactions.
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
(2022)
Article
Chemistry, Physical
Son Dong, Houqian Li, Iris K. Bloede, Abdullah J. Al Abdulghani, Edgard A. Lebron-Rodriguez, George W. Huber, Ive Hermans
Summary: The catalytic conversion of model compounds for plastic pyrolysis oil (1-octene, octadiene, octane, and toluene) over ZSM-5 in a fixed-bed reactor was investigated mechanistically. The conversion of 1-octene resulted in the production of benzene, toluene, xylene, coke, and hydrogen through a series of cracking, oligomerization, cyclization, and hydrogen transfer reactions. Octadiene mainly contributed to reactor fouling through thermal coking, while octane and toluene were converted through cracking reactions and disproportionation, dealkylation, and coking reactions, respectively. The use of mesoporous ZSM-5 maintained product selectivity for 70 hours in time-on-stream experiments.
APPLIED CATALYSIS B-ENVIRONMENTAL
(2023)
Article
Chemistry, Inorganic & Nuclear
Mohsen Rostami Sakha, Saeed Soltanali, Darush Salari, Mehdi Rashidzadeh, Parya Halimi Tabrizi
Summary: The study explored the impact of Si/Al ratio on hierarchical ZSM-5 catalysts, showing that a microchannel reactor can enhance the yield of light olefins.
JOURNAL OF SOLID STATE CHEMISTRY
(2021)
Article
Chemistry, Applied
Joseph P. Hittinger, Daniel F. Shantz
Summary: This study demonstrates the feasibility of cracking LDPE using H-ZSM-5 catalysts at reaction temperatures below 300°C by varying the textual properties and acid site content of the catalysts. Increasing the external surface area of H-ZSM-5 dramatically enhances LDPE conversion. Strong Bronsted acid sites are necessary for high conversion of LDPE at this temperature range. A low molecular weight model molecule provides insight into the cracking mechanism of LDPE over MFI catalysts.
MICROPOROUS AND MESOPOROUS MATERIALS
(2022)
Article
Chemistry, Applied
Tingting Qi, Jing Shi, Xishuo Wang, Kun Dong, Yong Luo, Jiawei Teng, Guang-Wen Chu, Hai-Kui Zou, Baochang Sun
Summary: ZSM-5 zeolites synthesized in a rotating packed bed show superior performance and higher yield in catalyzing olefin cracking reaction, compared to traditional methods like stirring tank reactor.
MICROPOROUS AND MESOPOROUS MATERIALS
(2021)
Article
Chemistry, Multidisciplinary
Shufang Zhao, Kyung Duk Kim, Lizhuo Wang, Ryong Ryoo, Jun Huang
Summary: A high-efficiency method for synthesizing hierarchical ZSM-5 zeolites with micropore and multistage mesopores using water-soluble carbon dots of various size distributions has been proposed. The obtained catalysts showed excellent catalytic performance and stability, attributed to improved reactant and product diffusion, anti-coking stability, suitable acidity, and increased accessibility of acid sites facilitated by multistage mesopores.
ADVANCED MATERIALS INTERFACES
(2021)
Article
Chemistry, Multidisciplinary
Huidong Liu
Summary: The conversion of solid residue from coal fly ash alumina extraction (FAAE) into aluminum-rich zeolite and silicon-rich zeolite was investigated in this research. The process involved alkali roasting, water leaching, and hydrothermal synthesis. The results showed that nearly 100% conversion of FAAE residue into zeolite products was achieved, and the tail liquid containing Na2CO3 could be completely recycled.
Article
Engineering, Chemical
Di Gao, Yibo Zhi, Liyuan Cao, Liang Zhao, Jinsen Gao, Chunming Xu
Summary: The effect of the acid properties of HZSM-5 on p-xylene (PX) yield in 1-hexene aromatization was investigated, and it was found that suitable L/B and EBA proportions can improve the selectivity of PX and aromatics yield.
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
(2022)
Article
Chemistry, Multidisciplinary
Yanfei Zhang, Liang Qi, Alicia Lund, Peng Lu, Alexis T. Bell
Summary: This study focused on acetone conversion to isobutene over isolated hafnium sites supported on Silicalite-1 and SiO2. It was found that Hf/Silicalite-1 exhibited faster reaction rates due to Hf-OH groups promoting the aldol condensation, while both Hf sites and Si-OH groups contributed to the reaction on Hf/SiO2.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2021)
Review
Chemistry, Multidisciplinary
Justin C. Bui, Chanyeon Kim, Alex J. King, Oyinkansola Romiluyi, Ahmet Kusoglu, Adam Z. Weber, Alexis T. Bell
Summary: The electrochemical reduction of carbon dioxide (CO2R) driven by renewable electricity offers a promising route for reusing CO2 and producing carbon-containing chemicals and fuels sustainably. Optimizing the catalyst microenvironment and selectivity, as well as controlling the electrolyte and operating conditions, are crucial for achieving economic viability and high product yields.
ACCOUNTS OF CHEMICAL RESEARCH
(2022)
Correction
Energy & Fuels
Chanyeon Kim, Justin C. Bui, Xiaoyan Luo, Jason K. Cooper, Ahmet Kusoglu, Adam Z. Weber, Alexis T. Bell
Review
Chemistry, Multidisciplinary
Justin C. Bui, Eric W. Lees, Lalit M. Pant, Iryna V. Zenyuk, Alexis T. Bell, Adam Z. Weber
Summary: Electrochemical synthesis using renewable energy to convert feedstocks into chemicals and fuels is promising, but understanding phenomena in porous electrode systems is challenging. Continuum modeling aids in understanding observed behaviors and guiding next-generation device design. Simulating multiscale phenomena in porous electrodes helps understand and improve the performance of electrochemical synthesis devices.
Article
Multidisciplinary Sciences
Hassan A. Aljama, Martin Head-Gordon, Alexis T. Bell
Summary: In this study, a high-throughput screening process using density functional theory was implemented to identify the energetically most favorable active sites in cation exchanged-zeolites, which is important for understanding catalysis and adsorption behaviors in zeolites.
NATURE COMMUNICATIONS
(2022)
Article
Chemistry, Physical
Joseph A. Gauthier, Zhou Lin, Martin Head-Gordon, Alexis T. Bell
Summary: This study investigates the mechanism of CO2RR under experimental conditions and reveals the differences in activation barriers between alkaline and acidic pathways, as well as the kinetic favorability of COH formation under high overpotential.
ACS ENERGY LETTERS
(2022)
Article
Chemistry, Physical
Tianyu Zhang, Justin C. Bui, Zhengyuan Li, Alexis T. Bell, Adam Z. Weber, Jingjie Wu
Summary: In this study, we developed segmented gas-diffusion electrodes (s-GDEs) to improve the management of CO intermediates in tandem catalysts, thereby enhancing C2+ Faradaic efficiency and current density.
Article
Chemistry, Physical
Paul Kim, Jeroen Van der Mynsbrugge, Martin Head-Gordon, Alexis T. Bell
Summary: Passive NOx adsorbers (PNAs) are proposed for trapping NOx in automotive exhaust during cold start. In this study, it is found that Pd+ cations can be formed through water adsorbed on zeolite acid sites and can be fully desorbed by adsorbing NO. These reactions are thermodynamically feasible and Pd+ is not formed in the absence of adsorbed water and can be readily reoxidized to Pd2+ by trace amounts of O2.
JOURNAL OF PHYSICAL CHEMISTRY C
(2022)
Article
Chemistry, Multidisciplinary
Liang Qi, Sonali Das, Yanfei Zhang, Danna Nozik, Bruce C. Gates, Alexis T. Bell
Summary: Catalysts for ethene hydroformylation were prepared by grafting Rh into nests of -SiOZn-OH or -SiOCo-OH species in BEA zeolite. The Rh dispersion increased with increasing M/Rh ratio and had a positive effect on the turnover frequency for ethene hydroformylation. The Co-containing catalyst exhibited higher activity and selectivity than the Zn-containing catalyst.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Chemistry, Physical
Danna Nozik, Alexis T. Bell
Summary: Ethane and propane derived from shale gas are preferred feedstocks for the production of aromatics. Ga/H-MFI zeolite exhibits high activity and selectivity for light alkane dehydroaromatization, with Ga3+ sites playing a crucial role. The enhanced activity of Ga/H-MFI is attributed to cooperative effects between Ga3+ sites and Bronsted acid protons.
Article
Chemistry, Multidisciplinary
Brooke Soobrian, Alex J. King, Justin C. Bui, Adam Z. Weber, Alexis T. Bell, Frances A. Houle
Summary: Artificial photosynthesis is a promising method to produce commodity chemicals using abundant chemical feedstocks and renewable energy sources. However, affordable and effective hands-on activities for primary school students to demonstrate and teach artificial photosynthesis are lacking. Educating young students on this topic is crucial for developing a diverse next-generation energy workforce. This study confirms that an active learning-based lesson plan using cheap and accessible materials can effectively educate a broad range of young students on artificial photosynthesis, as demonstrated by the improved understanding of fifth grade students before and after the lesson plan.
JOURNAL OF CHEMICAL EDUCATION
(2023)
Article
Nanoscience & Nanotechnology
Alex J. King, Adam Z. Weber, Alexis T. Bell
Summary: A metal-insulator-semiconductor (MIS) structure is an attractive photoelectrode-catalyst architecture for promoting photoelectrochemical reactions, such as the formation of H2 by proton reduction. Understanding how the insulator layer determines the photovoltage and what properties lead to high photovoltages is critical to the development of MIS structures for solar-to-chemical energy conversion.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Chemistry, Physical
John Safipour, Adam Z. Weber, Alexis T. Bell
Summary: Reactive carbon capture (RCC) is a promising solution for carbon capture and utilization. A systematic study found that RCC in aqueous environments is less effective and does not directly reduce into carbamate. Instead, the presence of amine solution suppresses the rate of CO formation while increasing that of H2.
ACS ENERGY LETTERS
(2023)
Article
Chemistry, Multidisciplinary
Chanyeon Kim, Alex J. King, Shaul Aloni, Francesca M. Toma, Adam Z. Weber, Alexis T. Bell
Summary: Photoelectrochemical carbon-dioxide reduction (PEC CO2R) is a promising method for producing chemicals and fuels using sunlight, water, and carbon dioxide. However, the focus has been mostly on producing C-1 products, while the production of C2+ products has been rarely demonstrated. In this study, a Cu/TiO2/p-Si photocathode/catalyst structure was investigated to understand the effects of semiconductor-insulator interactions and illumination direction on the performance and product distribution. Coating the Cu surface with a thin bilayer of Sustainion/Nafion significantly enhanced the current density and faradaic efficiency to ethylene.
ENERGY & ENVIRONMENTAL SCIENCE
(2023)
Article
Chemistry, Multidisciplinary
Annette Bohme, Justin C. Bui, Aidan Q. Fenwick, Rohit Bhide, Cassidy N. Feltenberger, Alexandra J. Welch, Alex J. King, Alexis T. Bell, Adam Z. Weber, Shane Ardo, Harry A. Atwater
Summary: We investigated how the micrometer-scale morphology of a CO2R gas diffusion electrode (GDE) affects the mass transport properties and local CO2R performance. Using fluorescence confocal laser scanning microscopy (CLSM), we created local pOH maps around a copper GDE and observed that pOH decreases in microtrenches compared to the electrode surface. Multiphysics simulations correlated well with experimental measurements and suggested that the decreased pOH inside microcavities leads to enhanced selectivity towards multicarbon products. This study highlights the importance of a GDE's micromorphology on CO2R performance.
ENERGY & ENVIRONMENTAL SCIENCE
(2023)
