Article
Multidisciplinary Sciences
Yulong Shan, Guangzhi He, Jinpeng Du, Yu Sun, Zhongqi Liu, Yu Fu, Fudong Liu, Xiaoyan Shi, Yunbo Yu, Hong He
Summary: This study demonstrates that the inhibition of Cu-SSZ-13 zeolite catalysts in the presence of NO2 is due to the strong oxidation leading to the formation of Cu-II species with low mobility. This distinctive behavior is explained by the higher energy barrier of the SCR reaction occurring at the Cu-II sites compared to the standard SCR reaction on dynamic binuclear sites.
NATURE COMMUNICATIONS
(2022)
Article
Chemistry, Applied
Viktoria Babic, Siddardha Koneti, Simona Moldovan, Nikolai Nesterenko, Jean-Pierre Gilson, Valentin Valtchev
Summary: NH4-SSZ-13 zeolite is etched using an aqueous solution of 40% NH4F under different time/temperature conditions to obtain hierarchical derivatives. The zeolites exhibit sensitivity to high temperature and high liquid-solid ratio treatments, which can lead to significant crystallinity losses. Careful tuning of these parameters is necessary to retain important characteristics in the hierarchical derivatives. The catalytic activity of the modified SSZ-13 is evaluated in n-propanol conversion.
MICROPOROUS AND MESOPOROUS MATERIALS
(2021)
Article
Chemistry, Physical
Hwangho Lee, Inhak Song, Se Won Jeon, Do Heui Kim
Summary: The study aims to reveal the mobility-dependent SCR reaction by controlling Cu species with different ion mobilities in Cu-SSZ-13. The results indicate that enhanced ion mobility leads to improved NH3-SCR activity, providing insights for designing rational catalysts by tuning ion mobility.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2021)
Article
Chemistry, Physical
Lucy Hillen, Volkan Degirmenci
Summary: Hierarchical mesoporous-microporous chabazite-type zeolites were synthesized using a dual-templating method in this study, showing fast adsorption-desorption kinetics for carbon dioxide capture with potential for larger-scale application. Template ratios were found to have a significant influence on their structure and performance. These materials are recyclable with minimal loss in crystallinity and carbon dioxide capture capacity.
Article
Chemistry, Applied
Aiyong Wang, Kunpeng Xie, Ashok Kumar, Krishna Kamasamudram, Louise Olsson
Summary: A concept of a layered Pd/SSZ-13 with Cu/SSZ-13 as PNA-SCR dual-layer monolith catalyst for NOx abatement is demonstrated. The dual-layer sample maintains most of the NOx storage capacity while the NOx desorption temperature is modified due to Cu/SSZ-13 as the top layer. The dual-layer concept shows interesting potential for NOx abatement, but requires further developments on the PNA material to ensure stable storage capacity.
Article
Chemistry, Multidisciplinary
Naomi Omori, Alessia Candeo, Sara Mosca, Ines Lezcano-Gonzalez, Ian K. Robinson, Luxi Li, Alex G. Greenaway, Paul Collier, Andrew M. Beale
Summary: This study uses multimodal imaging to show the distribution of different emissive deposits in Chabazite, distinguishing their spatial distributions, lifetime trends, spectral signals, and Raman signatures. It demonstrates differences in morphology between surface agglomerated deposits and larger subsurface deposits, as well as indicates the distribution of organic residue correlates with the distribution of silicon and aluminum in the crystal.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Applied
Ebrahim Delshad, Hafez Maghsoudi, Reza Alizadeh, Roghayeh Ebadi
Summary: A new approach for detemplation of SSZ-13 zeolite using ozone gas at lower temperatures has been investigated as an alternative to high-temperature calcination. The results show that this method can successfully remove the template and achieve porosity characteristics similar to thermally calcined samples. Additionally, using ozone treatment can significantly save energy compared to the calcination process.
MICROPOROUS AND MESOPOROUS MATERIALS
(2022)
Article
Chemistry, Multidisciplinary
Jun Li, Huazhen Rong, Cong Chen, Ziyi Li, Jiayu Zuo, Wenjian Wang, Xinjian Liu, Yixing Guan, Xiong Yang, Yingshu Liu, Xiaoqin Zou, Guangshan Zhu
Summary: Continuous and thin SSZ-13 zeolite membranes were successfully synthesized using dual templates, showing selective separation of N-2 over NO2 with good permeance and separation factor for the first time.
CHEMICAL RESEARCH IN CHINESE UNIVERSITIES
(2022)
Article
Chemistry, Applied
Yunhe Li, Xiubo Min, Wenhua Li, Qi Wang, Mingyang Shang, Yixuan Yu, Ping Tao, Tianjun Sun
Summary: Ag-doped ZSM-5 and SSZ-13 zeolites were prepared and showed enhanced adsorption performance for trace Xe and Kr capture. Ag-SSZ-13 exhibited higher Xe adsorption capacity and Xe/N-2 selectivity. GCMC simulations revealed the mechanism of enhanced Xe adsorption by Ag+ ions as adsorption sites.
MICROPOROUS AND MESOPOROUS MATERIALS
(2022)
Article
Chemistry, Applied
Hai Wu, Ye Lv, Jinli Zhang, You Han, Cuili Guo
Summary: Pure SSZ-13 zeolite was hydrothermally synthesized from Beta zeolite with the presence of TMAdaOH and additional silica. The conversion process involved decomposition of 5MRs into 4MRs and 6MRs, rearrangement into D6Rs, and crystallization into SSZ-13 zeolite. The calcined SSZ-13 zeolite prepared from Beta zeolite exhibited slightly lower surface area and pore volume, but stronger acidity compared to the sample from amorphous raw materials.
MICROPOROUS AND MESOPOROUS MATERIALS
(2021)
Article
Engineering, Chemical
Hua Liu, Xuechao Gao, Shengxian Wang, Zhou Hong, Xuerui Wang, Xuehong Gu
Summary: High-silica CHA (SSZ-13) zeolite membranes show great potential for CO2 separation, but practical application is limited by high investment costs. In this study, SSZ-13 zeolite membranes were successfully synthesized on hollow fibers with different pore sizes, achieving good CO2/CH4 selectivity and CO2 permeance on membranes with 150 nm pores. Evaluation of gas permeation found that small molecules mainly pass through zeolitic pores, while larger molecules are more sensitive to non-zeolitic pores.
SEPARATION AND PURIFICATION TECHNOLOGY
(2021)
Article
Engineering, Chemical
Xiaoxue Tang, Ye Zhang, Danni Meng, Xue Kong, Lin Kong, Heng'e Qiu, Ning Xu, Wanying Guo, Senlin Yang, Yanfeng Zhang
Summary: This study systematically investigated the effects of various parameters on the gel-less synthesis of SSZ-13 membranes for the first time. The key to successful gel-less synthesis is to create an environment similar to conventional hydrothermal synthesis and maintain a delicate balance between the template solution in the seed layer and at the bottom of the autoclave.
JOURNAL OF MEMBRANE SCIENCE
(2021)
Article
Engineering, Chemical
Minseong Lee, Gihoon Lee, Yanghwan Jeong, Woong-Jin Oh, Jeong-gu Yeo, Jung Hyun Lee, Jungkyu Choi
Summary: By studying the correlation between membrane and feed stream properties, the researchers proposed critical parameters to describe the representative module properties of the recovery, purity, and process efficiency of CO2. They also found that the process efficiency of the membrane unit was improved in a double-stage configuration, with noticeable improvements in CO2 purity and process efficiency, at a slight expense of CO2 recovery.
JOURNAL OF MEMBRANE SCIENCE
(2022)
Article
Chemistry, Applied
Kailu Zang, Junxia Ding, Wenna Zhang, Jindou Huang, Juanzhi Yan
Summary: This study extensively investigated the electronic structure of H-SSZ-13 and H-SAPO-34 zeolites and found that the catalytic activity of acidic zeolites is derived from the electronic distribution of their acidic catalytic centers. The acidity strength and polarization ability of the zeolites also affect their catalytic efficiency.
MICROPOROUS AND MESOPOROUS MATERIALS
(2022)
Article
Chemistry, Inorganic & Nuclear
Xiang Liao, Bing Wang, Ruiqi Yin, Weiguo Ren, Jing Li, Haotian Gan, Peng Lv, Weiren Bao, Jiancheng Wang, Liping Chang, Zhanggen Huang, Lina Han
Summary: Interzeolite transformation (IZT) was used to synthesize zeolite SSZ-13 with novel structure and composition. The effects of synthesis parameters on the crystallization of zeolite SSZ-13 were investigated. It was found that a feeding H2O/SiO2 ratio of 17.5-25, OH-/SiO2 ratio of 0.2-0.6, and Al2O3/SiO2 ratio of 30-40 resulted in zeolite SSZ-13 with high crystallinity and regular pore structure. Excessive water and high concentrations of OH- ions had negative effects on the synthesis of zeolite SSZ-13.
JOURNAL OF SOLID STATE CHEMISTRY
(2023)
Article
Materials Science, Multidisciplinary
Ryan Hill, Amanda S. Peretti, Leo J. Small, Erik D. Spoerke, Yang-Tse Cheng
Summary: In this study, the microstructure and mechanical properties of pure MMT and majority MMT/polyethylene composites pressed into dense pellets were examined. Utilizing characterization methods such as X-ray diffraction, atomic force microscopy, and scanning electron microscopy, important structure-property relationships in the clay-based materials were revealed.
JOURNAL OF MATERIALS SCIENCE
(2022)
Article
Chemistry, Multidisciplinary
Yong Yuan, Raul F. Lobo
Summary: In this study, the effect of different supports on indium speciation and propane dehydrogenation (PDH) was investigated. It was found that indium could form stable cationic species in CHA zeolite, leading to a catalyst with better selectivity and stability. This is important for studying other alkane dehydrogenation reactions.
Article
Chemistry, Physical
Yong Yuan, Raul F. Lobo, Bingjun Xu
Summary: Determining the structure of Ga-containing catalytic sites in Ga/H-ZSM-5 catalyst for propane dehydrogenation (PDH) has been a challenge due to the complexity of the system. In this study, two types of Ga species were differentiated using quantitative pulse titration reactions. The highly active divalent Ga species, identified as Ga2O22+, showed at least 18 times higher PDH activity than isolated Ga+ species. Additionally, only 30% of the observed Al pair sites were able to stabilize Ga2O22+, providing a method to probe the distribution of Al in zeolites.
Article
Electrochemistry
Claudina X. Kolesnichenko, Travis M. Anderson, Leo J. Small, Harry D. Pratt
Summary: Metal-based non-aqueous redox flow batteries face stability challenges. This study explores the use of metal-free bipyridinium compounds as anolytes, functionalized for increased electrochemical stability, achieving good battery performance and cycling stability.
Article
Engineering, Environmental
Sunkyu Kim, Leelavathi Annamalai, Raul F. Lobo
Summary: The combination of methane dehydroaromatization (MDA) and chemical looping (CL) combustion of hydrogen can overcome the thermodynamic constraints limiting conversion. The development of selective hydrogen-oxidation oxygen carriers in the CL is crucial for improving MDA performance. A novel oxygen carrier, silica-encapsulated Fe2O3, demonstrated high overall methane conversion and aromatics yield in a recirculating system. The silica layer prevented aromatics diffusion and promoted hydrogen transport and oxidation, while close physical contact between iron oxide particles and silica facilitated hydrogen conversion without full depletion of iron oxides.
CHEMICAL ENGINEERING JOURNAL
(2023)
Article
Engineering, Chemical
Stephen J. Percival, Leo J. Small, William B. Bachman, Mara E. Schindelholz, Tina M. Nenoff
Summary: Nanoporous materials, including MOFs and inorganic zeolites, are being explored as gas sensor materials due to their selectivity and durability. Long-term testing under varying conditions is crucial to evaluate their stability and response. In this study, nanoporous materials-based sensors were tested for 3 months under dry or humid conditions, and the results showed relative stability in dry conditions but degradation in the humid environment. These findings highlight the need for long-term testing of emerging nanoporous sensors under specific environmental conditions.
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
(2023)
Article
Chemistry, Physical
Adam M. Maraschky, Melissa L. Meyerson, Stephen J. Percival, Daniel R. Lowry, Stephen Meserole, John N. Williard, Amanda S. Peretti, Martha Gross, Leo J. Small, Erik D. Spoerke
Summary: Low-temperature molten sodium batteries using molten sodium anodes, NaSICON solid-state separators, and molten halide salt catholytes have the potential to be low-cost and environmentally friendly energy storage technologies. This study examined the performance of batteries using NaI-AlCl3-based catholytes with different Lewis acidities. It was found that batteries with basic catholytes containing more than 50 mol % NaI maintained high energy efficiency for a long duration, while batteries with acidic catholytes declined in energy efficiency. The interface between the NaSICON separator and the catholyte was identified as the key factor influencing battery performance.
JOURNAL OF PHYSICAL CHEMISTRY C
(2023)
Article
Chemistry, Physical
Mingchun Ye, Mi Jen Kuo, Raul F. Lobo
Summary: The substrate scope of the Diels-Alder-Dehydration reaction was expanded to the deactivated bifuran structure. Dimethyl biphenyl-4,4 '-dicarboxylate (1) and methyl 5- [4-(methoxycarbonyl)phenyl]-2-furoate (2) were synthesized via metal-triflate-catalyzed Diels-Alder-Dehydration reaction with ethene. A 31% yield of (1) was obtained using Sc(OTf)3 catalyst, and a 76.6% yield of (2) was obtained using La(OTf)3 catalyst. This approach is selective to the 4,4 '-dicarboxylates and avoids the methyl-group oxidation step in the dimethyl-biphenyl route.
MOLECULAR CATALYSIS
(2023)
Article
Electrochemistry
Adam M. Maraschky, Stephen J. Percival, Rose Y. Lee, Melissa L. L. Meyerson, Amanda S. Peretti, Erik D. Spoerke, Leo J. Small
Summary: Iodide redox reactions in molten NaI/AlCl3 generate surface-blocking films, limiting the cycling rates and energy densities of molten sodium batteries. The source of the reaction rate limitations is revealed through an experimental investigation at 110 degrees C. The film formation is influenced by electrode material, Lewis acidity, and molar ratio of I-/I-3(-) in the molten salt electrolytes.
JOURNAL OF THE ELECTROCHEMICAL SOCIETY
(2023)
Article
Chemistry, Physical
Yong Yuan, Raul F. Lobo
Summary: We investigated the active sites of Zn/H-ZSM-5 catalysts for propane dehydrogenation and found that [Zn-OH]+ and [Zn-O-Zn]2+ sites in H-ZSM-5 are more active and selective than isolated Zn2+ sites. The preparation of H-ZSM-5 with abundant Al pairs may be a strategy to form stable and selective Zn/H-ZSM-5 catalysts for propane dehydrogenation.
Article
Chemistry, Multidisciplinary
Gwendolyn J. Gregory, Cong Wang, Sunitha Sadula, Sam Koval, Raul F. Lobo, Dionisios G. Vlachos, Eleftherios Terry Papoutsakis
Summary: There is limited research on microbial deconstruction or functionalization of polyolefin's recalcitrant backbone. However, microbes can utilize polyolefin deconstruction products. In this study, researchers combined chemical catalysis and bioconversion to valorize polyethylene (PE) deconstruction products. They found microbial consortia derived from soil from local recycling plants that can utilize the PE-deconstruction product mix as the sole carbon source.
ACS SUSTAINABLE CHEMISTRY & ENGINEERING
(2023)
Article
Chemistry, Physical
Ryan Hill, Amanda Peretti, Leo J. Small, Erik D. Spoerke, Yang-Tse Cheng
Summary: High-conductivity solid electrolytes like NaSICON are becoming increasingly important for safe, reliable battery-based energy storage. However, the demands for high current density, low temperature operation, and long-duration storage challenge the limitations of solid electrolytes. This study investigates the penetration of molten sodium into NaSICON at high current densities.
ACS APPLIED ENERGY MATERIALS
(2023)
Article
Nanoscience & Nanotechnology
Leo J. J. Small, Simon M. M. Vornholt, Stephen J. J. Percival, Melissa L. L. Meyerson, Mara E. E. Schindelholz, Karena W. W. Chapman, Tina M. M. Nenoff
Summary: Competitive gases have a significant impact on the electrical response of Ni-MOF-74 sensors, with the presence of NO2 causing a significant decrease in resistance. H2O and SO2 also lower the resistance, while CO2 has a smaller effect. These findings contribute to the improvement of gas detection properties in MOF materials.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Chemistry, Physical
Yong Yuan, Raul F. Lobo
Summary: The active sites of Zn/H-ZSM-5 catalysts for propane dehydrogenation were investigated using in situ FTIR spectroscopy and kinetics method. It was found that [Zn-OH](+) and [Zn-O-Zn](2+) sites are more active and selective for the dehydrogenation reaction, while [Zn-OH](+) species sublimate over time leading to catalyst deactivation. The rate-determining step is propane adsorption and dissociation, and H2 desorption is fast.
Article
Chemistry, Physical
Jian Pan, Raul F. F. Lobo
Summary: Mn-ZSM5 catalysts exhibit high reaction rates, C2H4 selectivity, and stability for the ethane dehydrogenation reaction. The specific reaction rate increases with the Mn loading until reaching the optimal Mn amount of 3.4 wt% for zeolites with a Si/Al ratio of 12. Characterizations and analysis reveal the presence of MnO2 nanoparticles and (MnOH)+ groups on the external surface of the zeolite, with the former acting as catalytic sites and the latter aiding in stabilization of oxide particles. Mn-ZSM5 samples can catalyze EDH for over 150 h at 600 degrees C with a high reaction rate (>10 mmolC2H6 gcat-1 h-1) and high C2H4 selectivity (>98%). Furthermore, the spent catalyst can be regenerated by calcination in dry or wet air (3% steam).
CATALYSIS SCIENCE & TECHNOLOGY
(2023)