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, 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
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
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)
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, Applied
Zhanwei Xu, Peifang Yan, Changhui Liang, Songyan Jia, Xiumei Liu, Z. Conrad Zhang
Summary: This study reports an enhanced catalytic Guerbet reaction of 1-butanol to 2-ethyl-1-hexanol using a series of Cp*Ir complexes, achieving a record turnover number of 14047. The mechanistic study indicated that the steric and conjugation effects play a role in the high selectivity of 2-EH from 1-butanol.
CHINESE JOURNAL OF CATALYSIS
(2021)
Article
Chemistry, Physical
Zongyang Liu, Jie Li, Yuan Tan, Luyao Guo, Yunjie Ding
Summary: The direct conversion of biomass-derived ethanol to high-valued-added chemicals through the Guerbet coupling process using Cu catalysts supported by mixed-oxides has been studied. The addition of Cu enhances the dehydrogenation of ethanol and the H-transfer during the Guerbet coupling process. The mixed-oxides support provides the acid-base property for intermediate transformation.
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
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
Alex M. Davies, Zhong-Yuan Li, Corey R. J. Stephenson, Nathaniel K. Szymczak
Summary: We report a ruthenium-catalyzed tandem Guerbet-alkylation strategy for the valorization of ethanol. The development of ClRu(5-Mebpi)(PPh3)2(bpi = 1,3-bis(2 '-pyridylimino)isoindolate) catalyst led to the efficient production of higher-order alcohols from ethanol in short reaction times (2 h), achieving the highest TON (155,890) and TOF (12,690 h-1) for a homogeneous catalyst reported so far.
Article
Chemistry, Applied
Anna Maria Raspolli Galletti, Claudia Antonetti, Sara Fulignati, Domenico Licursi, Stefano Dell'Omo, Patricia Benito, Erwin Wilbers, Hero Jan Heeres
Summary: The conversion of bio-alcohols to chemicals and fuels is crucial for the transition towards bioeconomy. Cu/Mg/Al mixed oxide catalysts derived from different hydrotalcites showed tunable catalytic performance in batch and continuous flow reactors for the conversion of nBuOH. Catalysts with lower Cu content exhibited activity in both Guerbet condensation and dehydrogenative coupling reactions, while the catalyst with the highest Cu content showed high selectivity towards butyl butyrate formation. Batch reaction showed gradual deactivation of the catalyst systems, while the study in flow reactor revealed good activity and stability of the Cu7.6 catalytic system.
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
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
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, Physical
Serena Todaro, Francesco Frusteri, Dariusz Wawrzynczak, Izabela Majchrzak-Kuceba, Juan-Francisco Perez-Robles, Catia Cannilla, Giuseppe Bonura
Summary: In this study, a series of mono- and bimetallic copper and iron samples were prepared on micro-spherical silica as a carrier through impregnation method, and used for the methanol synthesis via CO2 hydrogenation. Micro-spherical silica demonstrated advantages in absorption capacity and optimal distribution of active phases on its surface, as well as excellent heat resistance properties and chemical stability. The mutual interaction of copper and iron was found to promote the formation of methanol, especially when iron enrichment on the silica support favored the presence of a larger concentration of oxygen vacancies, leading to higher CO2 adsorption and selective methanol production. Surface reconstruction phenomena rather than coke or metal sintering were responsible for the slight loss of activity recorded on the catalyst samples during the initial phase of reaction, with no significant change in the product selectivity.
Article
Chemistry, Multidisciplinary
Xianyuan Wu, Mario De Bruyn, Katalin Barta
Summary: Cyclic primary amines are important building blocks in many chemicals and pharmaceuticals. A powerful catalytic strategy was developed to convert guaiacol into cyclohexylamine with high yield. The method can also be applied to other types of guaiacols. It was found that crude bio-oil from birch lignocellulose can be transformed into a product mixture rich in 4-propylcyclohexylamine.
Article
Multidisciplinary Sciences
Xianyuan Wu, Maxim Galkin, Tobias Stern, Zhuohua Sun, Katalin Barta
Summary: This article presents a biorefinery strategy for constructing polyester analogues of polyethylene terephthalate from woody biomass, which are promising candidates for the circular economy.
NATURE COMMUNICATIONS
(2022)
Article
Multidisciplinary Sciences
Shijie Yu, Xinyue Dong, Peng Zhao, Zhicheng Luo, Zhuohua Sun, Xiaoxiao Yang, Qinghai Li, Lei Wang, Yanguo Zhang, Hui Zhou
Summary: This study presents a hydrothermal system that allows independent control of temperature and pressure, enabling fast synthesis of carbon sub-micron spheres from cellulose. By decoupling temperature and pressure, the degradation temperature of cellulose is significantly reduced, leading to accelerated production of carbon sub-micron spheres and reduced carbon emissions.
NATURE COMMUNICATIONS
(2022)
Article
Chemistry, Multidisciplinary
Xianyuan Wu, Mario De Bruyn, Julia Michaela Hulan, Henrique Brasil, Zhuohua Sun, Katalin Barta
Summary: In this study, a catalytic methodology is developed for the transformation of beech lignin-derived dimers and oligomers into industrially relevant 1,4-cyclohexanediol and 1,4-cyclohexanediamine. The proposed two-step catalytic sequence, using commercially available RANEY (R) Ni catalyst, enables efficient and selective conversion. This process has great potential for future industrial synthesis of 1,4-cyclohexanediamine from renewable resources.
Article
Polymer Science
Xianyuan Wu, Dan Xu, Mario De Bruyn, Gregor Trimmel, Katalin Barta
Summary: In this study, a family of bio-based polycarbonates (PC-MBC) has been described, which are based on a unique lignin-derived aliphatic diol (MBC) sustainably sourced from lignin oxidation mixture. The detailed structure analysis of these polycarbonates has been confirmed by a series of 2D NMR characterizations. The PC-MBC displayed a wide achievable T-g range of 117-174 degrees C and high T-d5% of >310 degrees C by variation of the ratio of the stereoisomers of MBC, offering great substitution perspectives towards a bisphenol-containing polycarbonates. Nonetheless, the presented PC-MBC polycarbonates were film-forming and transparent.
Article
Chemistry, Physical
Fabio Salomone, Giuseppe Bonura, Francesco Frusteri, Micaela Castellino, Marco Fontana, Angelica Monica Chiodoni, Nunzio Russo, Raffaele Pirone, Samir Bensaid
Summary: The direct hydrogenation of CO2 into dimethyl-ether (DME) was studied using ferrierite-based CuZnZr hybrid catalysts. Three different samples were synthesized with different techniques and mass ratios of oxides/zeolite. The activity of the catalysts was found to be higher at higher oxide/zeolite weight ratios. Catalysts prepared by impregnation and coprecipitation showed comparable DME productivity at lower mass ratios, while the physically mixed sample exhibited high CO2 hydrogenation activity but low selectivity towards methanol and DME. Durability tests revealed a progressive loss in activity over time.
Article
Chemistry, Multidisciplinary
Xianyuan Wu, Mario De Bruyn, Gregor Trimmel, Klaus Zangger, Katalin Barta
Summary: Polyesters obtained from the polycondensation of lignin-derived bicyclic diol with cellulose-derived diesters showed high-performance properties and potential applications. The use of isomerically pure diol resulted in significant effects on the physical properties of the polyesters. Furthermore, the efficient depolymerization of the polyesters and conversion into high-performance jet fuel additives was demonstrated.
ACS SUSTAINABLE CHEMISTRY & ENGINEERING
(2023)
Editorial Material
Chemistry, Multidisciplinary
John Vakros, Evroula Hapeshi, Catia Cannilla, Giuseppe Bonura
Article
Chemistry, Multidisciplinary
Xianyuan Wu, Mario De Bruyn, Katalin Barta
Summary: Lignin has great potential to produce value-added chemicals and high performing polymeric materials. However, the depolymerization of lignin leads to complex product streams, containing dimers and higher molecular weight fragments. The subsequent catalytic valorization of these streams, which contain difficult-to-break C-C covalent bonds, is challenging and has received less attention. This review presents recent advances in sustainable biorefinery strategies for the production of well-defined chemicals and polymeric materials, with a focus on depolymerized lignin oils containing high molecular weight fractions. (Bio)catalytic funneling is highlighted as a key operation to overcome separation and purification challenges.
CHEMICAL COMMUNICATIONS
(2023)
Article
Chemistry, Multidisciplinary
Antonio A. Castillo-Garcia, Christian Oliver Kappe, David Cantillo, Katalin Barta
Summary: In this study, an environmentally friendly method for extracting important phenolic chemicals from lignin was developed using electrochemical conversion and chemical functionalization steps. This method enables the transformation of lignocellulose into nitrogen-containing chemicals, such as aniline derivatives, to meet industrial demands.
Article
Chemistry, Physical
Xianyuan Wu, Mario De Bruyn, Katalin Barta
Summary: Primary amines are important for the synthesis of various industrial products. A comprehensive catalytic strategy allows for the direct sourcing of diverse primary amines from lignocellulosic biomass with minimal purification effort. The core of the methodology is the efficient RANEY (R) Ni-catalyzed hydrogen-borrowing amination of alcohol intermediates.
CATALYSIS SCIENCE & TECHNOLOGY
(2022)
Article
Chemistry, Multidisciplinary
Thomas Freese, Balint Fridrich, Stefano Crespi, Anouk S. Lubbe, Katalin Barta, Ben L. Feringa
Summary: Lignin, as the largest natural source of functionalized aromatics, holds great potential for synthesis of aromatic products. However, the diversification of these structures and their applications have not been well-studied. In this study, a novel light-driven unidirectional molecular motor was synthesized from a specific aromatic platform chemical derived from lignocellulose. The synthetic path followed the principles of green chemistry and aimed to maintain the intrinsic functionality of the lignin-derived platform molecule.
Article
Chemistry, Multidisciplinary
Zhenlei Zhang, Ciaran W. Lahive, Jozef G. M. Winkelman, Katalin Barta, Peter J. Deuss
Summary: Selective lignin depolymerisation on the prime beta-O-4 motif provides an opportunity to obtain valuable functionalized phenolic monomers. Diol-stabilized acidolysis of lignin with sulfuric acid, triflic acid or triflate salts is a proven beta-O-4 cleavage methodology that forms acetals by trapping of released reactive aldehydes. The study shows that the reaction selectivity can be manipulated by controlling reaction parameters such as temperature, ethylene glycol and water content.
