Article
Chemistry, Physical
J. Tyler Prillaman, Naomi Miyake, Robert J. Davis
Summary: The study investigated the catalytic conversion of ethanol to butanol and butadiene using calcium phosphate materials pretreated at different temperatures. Low temperature pretreatment resulted in high selectivity for acid-catalyzed products, while high temperature pretreatment led to the formation of coupling products.
Article
Chemistry, Physical
Jie Li, Lu Lin, Yuan Tan, Shiyi Wang, Wenshao Yang, Xingkun Chen, Wenhao Luo, Yun-Jie Ding
Summary: The study prepared Cu/NiAlOx catalysts through hydrothermal precipitation method and found that Cu addition enhanced the reactivity in the conversion of ethanol into butanol. With sustained ethanol conversion of over 35% and butanol selectivity of around 45%, the catalyst exhibited excellent stability over time.
Article
Chemistry, Physical
Jachym Muck, Jaroslav Kocik, Martin Hajek, Zdenek Tisler, Karel Frolich, Ales Kasparek
Summary: This study focuses on the catalytic synthesis of butanol from ethanol in a microflow reactor. Different catalysts have varying effects on the formation of butanol and other products, with temperature increasing ethanol conversion but decreasing selectivity towards butanol.
APPLIED CATALYSIS A-GENERAL
(2021)
Article
Nanoscience & Nanotechnology
Sabrine M. Cypher, Magnus Pauly, Leslie G. Castro, Carrie L. Donley, Paul A. Maggard, Karen I. Goldberg
Summary: This study used a molecular catalyst integrated into a carbon nitride support to upgrade ethanol to n-butanol, which is one of the first examples of a supported molecular catalyst performing the Guerbet process. Initial studies using PTI with lithium or transition-metal cations imbedded in the support did not produce significant amounts of n-butanol. However, 59% selectivity for butanol (13% yield) was obtained at 145°C when using PTI-LiCl treated with [(Cp*)IrCl2] along with sodium hydroxide.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Chemistry, Multidisciplinary
P. M. Mahitha, S. Nakul, Naveen V. Kulkarni, Balaji R. Jagirdar, William D. Jones
Summary: A series of Ru(iii) complexes with accessible N-donor organic pincer ligands were used as catalysts in the Guerbet upgrading reaction of ethanol under aerobic conditions. The tridentate ligand systems with amino-dimethyl and pyridine backbones showed higher efficiency compared to the bidentate ligand systems with phenyl and ethene backbones. Potassium t-butoxide was the most compatible base for this catalyst system. A reaction with 0.1 mol% catalyst and 10 mol% potassium t-butoxide yielded 27% n-butanol at 71% selectivity (150 degrees C, 24 h).
NEW JOURNAL OF CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Machen Xue, Bolun Yang, Chungu Xia, Gangli Zhu
Summary: Acquiring higher alcohols (C6+-OH) from renewable ethanol instead of fossil resources is of special significance for carbon neutrality. In this study, a recyclable Ni/bio-apatite catalyst derived from biomass was developed for upgrading ethanol to higher alcohols. The catalyst showed high selectivity for C6+-OH without the need for alkali additives, ligands, and extra hydrogen. The porous structure and coordination between metal and alkaline sites played key roles in achieving high C6+-OH selectivity.
ACS SUSTAINABLE CHEMISTRY & ENGINEERING
(2022)
Article
Green & Sustainable Science & Technology
Karel Frolich, Jan Malina, Martin Hajek, Jachym Mueck, Jaroslav Kocik
Summary: The Guerbet reaction is an important way to transform ethanol to 1-butanol in various industries. This study focuses on the ethanol transformation using Mg-Al mixed oxides with copper or cobalt as catalysts in a microflow reactor. The results show that the series of catalysts containing copper exhibited higher conversion of ethanol and selectivity to butanol compared to the series containing cobalt. The study also verified a multi-step mechanism involving aldol condensation for both catalyst series and reaction conditions.
CLEAN TECHNOLOGIES AND ENVIRONMENTAL POLICY
(2023)
Article
Chemistry, Multidisciplinary
Oksana Zikrata, Olga Larina, Karina V. Valihura, Pavlo Kyriienko, Dmytro Yu Balakin, Ivan Khalakhan, Katerina Veltruska, Andraz Krajnc, Gregor Mali, Sergiy O. Soloviev, Svitlana M. Orlyk
Summary: Calcium-containing hydroxyapatite catalysts modified with magnesium have been found to be effective in producing higher alcohols, showing superior selectivity and resistance to deactivation.
ACS SUSTAINABLE CHEMISTRY & ENGINEERING
(2021)
Article
Engineering, Chemical
Olga Larina, Pavlo Kyriienko, Nataliya D. Shcherban, Pavlo S. Yaremov, Dmytro Yu Balakin, Ivan Khalakhan, Katerina Veltruska, Sergiy O. Soloviev, Svitlana M. Orlyk
Summary: Carbon-supported Mg-Al oxide hybrid catalysts were prepared and characterized for aqueous ethanol conversion into 1-butanol, showing enhanced catalytic activity and stability over time on stream compared to Mg-Al oxides when using both rectified and aqueous ethanol as feed. The redistribution of active sites of the Mg-Al oxide phase over a highly dispersed support was suggested to be the cause of the enhanced activity of the hybrid catalysts.
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
(2021)
Article
Chemistry, Inorganic & Nuclear
Anthony M. S. Pembere, Denis Magero, Godfrey O. Barasa, Gershom Kyalo Mutua, Hitler Louis, Haiming Wu
Summary: In this study, the mechanism of ethanol coupling to butanol over small metal clusters (copper, silver, and gold) was investigated. It was found that charge transfer interactions between the clusters and the alcohol play a crucial role in initiating the reactions. Ethanol was found to have a stronger adsorption on gold compared to silver and copper, as determined by binding energy calculations. The nature of bonding was studied using natural bond orbital (NBO) analysis and quantum theory of atoms-in-molecules (QTAIM). The reactive intermediates, activated complexes, transition states, and bond breaking on different metal cluster catalysts were calculated along with cycle kinetics. High resolution mass spectroscopy was used to observe the coupling products, which confirmed the kinetic- and thermodynamic-allowed reaction pathway of Guerbet coupling of ethanol. The highest selectivity for butanol (61%) was achieved after 2 hours of reaction time, while the highest ethanol conversion (91%) was achieved after 5 hours of reaction time.
JOURNAL OF CLUSTER SCIENCE
(2023)
Article
Chemistry, Multidisciplinary
Zhihui Shao, Xinyan Li, Xiaoyu Zhang, Mingqin Zhao
Summary: Bioethanol, produced in large quantities through the fermentation of sugar-containing crops and lignocellulosic materials, requires advanced methods to convert it into fine chemicals. This study presents the synthesis of higher-order alcohols by cross-coupling ethanol with primary alcohols under solvent-free conditions, using a low amount of a selective manganese pincer complex as catalyst and a stoichiometric amount of sodium ethoxide. Poisoning experiments confirm the homogeneity of the catalysis system.
ENVIRONMENTAL CHEMISTRY LETTERS
(2023)
Article
Chemistry, Physical
Richard L. Wingad, Laurence Birch, Joshua Farndon, Jason Lee, Katy J. Pellow, Duncan F. Wass
Summary: Ruthenium complexes with tetradentate PNNP donor ligands exhibit different selectivity in Guerbet catalysis compared to bis bidentate PN complexes, producing a mixture of n-butanol (17%), sec-butanol (14%) and ethyl acetate (66%) instead of the usual 90%+ selectivity to n-butanol. Tridentate PNP ruthenium complexes also produce sec-butanol and achieve 71% selectivity to this isomer in optimized conditions. The same tri- and tetradentate complexes are efficient catalysts for converting methanol/ethanol mixtures to isobutanol with up to 97% selectivity.
Article
Biochemistry & Molecular Biology
Anna Vikar, Ferenc Lonyi, Amosi Makoye, Tibor Nagy, Gyula Novodarszki, Robert Barthos, Blanka Szabo, Jozsef Valyon, Magdolna R. Mihalyi, Dhanapati Deka, Hanna E. Solt
Summary: The catalytic conversion of ethanol to 1-butanol using MgO-Al2O3 mixed oxide catalysts was investigated. The study focused on the relationship between acid-base and catalytic properties and the role of active metal in hydrogen transfer reactions. The results showed that the MgO-Al2O3 catalyst with a higher amount of strong-base and medium-strong Lewis acid sites exhibited the highest selectivity and yield of 1-butanol. The presence of metal improved the activity, but also decreased the selectivity due to accelerated side reactions at higher temperatures. DRIFT spectroscopy revealed that the active metal promoted hydrogen transfer from H2 in a narrow temperature range.
Article
Chemistry, Physical
Anthony M. S. Pembere, Haiming Wu, Pan An, Dennis Magero, Hitler Louis, Zhixun Luo
Summary: This study presents the catalytic role of titanium clusters in methanol coupling reactions, revealing the reaction mechanism through experimental and computational approaches.
CHEMICAL PHYSICS LETTERS
(2022)
Article
Chemistry, Physical
Joachim Pasel, Johannes Haeusler, Dirk Schmitt, Helen Valencia, Joachim Mayer, Ralf Peters
Summary: The catalytic upgrading of CO2-based ethanol into valuable products, such as higher alcohols, is an increasingly popular research topic. Among these products, carbon-neutral n-butanol has the potential to replace a significant portion of conventional gasoline in the transportation sector. The Guerbet reaction, particularly the homo aldol condensation of acetaldehyde, has been studied as a promising synthesis route for n-butanol. In this study, the Temporal Analysis of Products methodology was used to investigate the reaction, with lanthanide oxides supported on activated carbon as catalysts. The research revealed the formation of butanol through the aldol condensation of acetaldehyde, as well as its decomposition into CO, CH4, and H2. Carbonaceous deposits were formed when acetaldehyde was pulsed onto the catalyst surface, but catalyst regeneration was successfully achieved through O2 pulsing. Other reaction routes leading to acidic acid, ethyl acetate, or diethyl ether were excluded through experimental tests.
APPLIED CATALYSIS B-ENVIRONMENTAL
(2023)
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
Engineering, Chemical
Can Ekici, Christopher R. Ho, Joseph F. DeWilde, Lorenz T. Biegler, Paul M. Witt
Summary: This study presents the development and application of optimization strategies for mixed-catalyst, single-shot reactors in syngas to olefin (STO) processes. Finding the optimal catalyst distribution is challenging due to poorly conditioned singular optimal control problems. The graded bed and partial-moving finite-element approaches were used to maximize the olefins yield. An increase of 1.3% in yield was achieved from one zone to three zones, and further improved by 0.2% to the infinite dimensional solution. These improvements can be implemented without additional investment. The results suggest the potential application of mixed-catalyst single shot reactor beds for enhancing reactor performance in other reaction mechanisms.
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
(2023)
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)
