Article
Chemistry, Applied
Barbara C. Miranda Morales, Braulio Andres Ortega Quesada
Summary: The conversion of glycerol to hydroxyacetone was studied using various catalysts, with the monometallic Cu/γ-Al2O3 and Cu/TiO2 catalysts showing higher conversion and selectivity. Additionally, high selectivity to lactic acid was achieved over the Cu/TiO2 catalyst.
Article
Chemistry, Multidisciplinary
Qiang Nie, Jiaqi Si, Chao Meng, Tian Lan, Weidong Sun, Guofeng Zhao, Ye Liu, Yong Lu
Summary: The Cu/Sn-beta system enables efficient synthesis of methyl acetate with high selectivity and low methanol conversion. The catalyst facilitates the formation of bridged-adsorbed CH2O* through electron transfer and Cu(0) dehydrogenation, and further transforms it into formaldehyde through a C-C coupling reaction. Finally, formaldehyde condenses with adsorbed CH3O* on the Cu-0 site to form methyl acetate.
ACS SUSTAINABLE CHEMISTRY & ENGINEERING
(2022)
Article
Chemistry, Physical
Mitsunori Araki, Takeru Sato, Takahiro Oyama, Shoma Hoshino, Koichi Tsukiyama
Summary: In this study, gas-phase overtone bands of methyl acetate and ethyl acetate were detected using incoherent broad-band cavity-enhanced absorption spectroscopy. The observed overtone bands were analyzed with theoretical calculations to determine their peaks and related parameters.
CHEMICAL PHYSICS LETTERS
(2022)
Article
Chemistry, Physical
Thanh Khoa Phung
Summary: This review focuses on the development of Cu-based catalysts for ethanol dehydrogenation and dehydrogenative coupling reactions, and discusses the effects of Cu charge, particle size and dispersion, support, promoters and reaction conditions on the catalytic activity and selectivity.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2022)
Article
Chemistry, Physical
Takashi Yamamoto, Hirotaka Mine, Shoki Katada, Taketo Tone
Summary: The direct synthesis of ethyl acetate from ethanol was studied using Cu catalysts supported on various acid-base metal oxides, ZrO2-based oxides, and homemade amorphous-, monoclinic- and tetragonal zirconia prepared from the same Zr source. XRD, XAFS, TG-DTA characterization and surface area measurement were performed to analyze the catalysts. The effects of the crystalline phase of ZrO2 support on selective ethyl acetate production were discussed based on the yields and products ratio. Among the different catalysts tested, amorphous-type ZrO2 was found to be the most suitable for selective ethyl acetate formation without any surface modifications. The presence of acid sites on the surface of monoclinic-type ZrO2 catalysts possibly promoted an unfavorable acetaldehyde condensation reaction, but the addition of Na+ for poisoning increased the selectivity of ethyl acetate formation. The coordination environment of Cu species for fresh and spent catalysts was also discussed.
APPLIED CATALYSIS B-ENVIRONMENTAL
(2023)
Article
Chemistry, Applied
Shihui Zou, Zhinian Li, Qiuyue Zhou, Yang Pan, Wentao Yuan, Lei He, Shenliang Wang, Wu Wen, Juanjuan Liu, Yong Wang, Yonghua Du, Jiuzhong Yang, Liping Xiao, Hisayoshi Kobayashi, Jie Fan
Summary: In this study, methyl radicals generated by La2O3 were shown to selectively couple on the surface of Na2WO4/SiO2 at low temperatures, significantly improving the C-2 selectivity and yield. Na2WO4 nanoclusters were identified as the active sites for methyl radical coupling. This new bifunctional OCM catalyst system holds promise for achieving high OCM performance at lower reaction temperatures.
CHINESE JOURNAL OF CATALYSIS
(2021)
Article
Chemistry, Multidisciplinary
Lei-Yang Zhang, Nai-Xing Wang, Zhan Yan, Yue-Hua Wu, Xue-Wang Gao, Ke Feng, Dumitra Lucan, Yalan Xing
Summary: An environmentally friendly method for the oxidative coupling of alpha-methyl substituted N-heteroarenes with indoles is reported. This method features simple operation and a wide range of substrates.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Article
Chemistry, Multidisciplinary
Huan Guo, Ningning Sun, Juan Guo, Tai-Ping Zhou, Langyu Tang, Wentao Zhang, Yaming Deng, Rong-Zhen Liao, Yuzhou Wu, Guojiao Wu, Fangrui Zhong
Summary: In this study, the highly enantioselective oxidative cross-coupling of 3-hydroxyindole esters with various nucleophilic partners using copper efflux oxidase as catalyst was reported. The biocatalytic transformation produced functionalized 2,2-disubstituted indolin-3-ones with excellent optical purity (90-99% ee) that showed anticancer activity against MCF-7 cell lines, as indicated by preliminary biological evaluation. Mechanistic studies and molecular docking results revealed the formation of a phenoxyl radical and enantiocontrol facilitated by a suitable enzyme chiral pocket. This study is significant in expanding the catalytic repertoire of natural multicopper oxidases and enlarging the synthetic toolbox for sustainable asymmetric oxidative coupling.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Physical
Yingqiang Ma, Mianyan Yang, Langfeng Tang, Shuanglin Zheng, Yafeng Fu, Qiuyue Sheng, Wanzhong Yin
Summary: This study investigates the collectivity and selectivity mechanisms of ethyl isobutyl xanthogenic acetate (EIBXAC) as a novel collector in the flotation of secondary copper sulfide minerals. The results show that EIBXAC has a better collecting effect on covellite and digenite compared to ammonium dibutyl dithiophosphate (ADD). The artificial mixed-mineral experiment demonstrates that EIBXAC can improve the grade of copper concentrate while maintaining the same recovery, indicating higher efficiency and selectivity. The adsorption and DFT calculations confirm that EIBXAC chemically adsorbs onto the mineral surface, with stronger adsorption capacity for covellite and digenite than ADD.
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
(2022)
Article
Chemistry, Applied
Lang Liu, Guojin Sun, Jun Zhang
Summary: This study presents a protocol for synthesizing 2,4,5-substituted imidazole-bearing methyl groups using A3-coupling cyclization with calcium carbide as the acetylene source, reacting with amidines and aldehydes. This methodology is characterized by several features, including the utilization of a solid alkyne source, readily accessible starting materials, and applicability to 34 examples.
ADVANCED SYNTHESIS & CATALYSIS
(2023)
Article
Chemistry, Applied
Hongyu Xia, Ganghu Wang, Dongbo Zhao, Chunyin Zhu
Summary: A visible-light-induced oxidative coupling reaction of arylboronic acids for the synthesis of biaryls has been developed. The reaction utilizes polydentate hydrazones as a bifunctional catalyst and proceeds smoothly at room temperature. It is compatible with a wide range of functional groups. The study of UV-Vis spectrum shows that hydrazone and its complex with CuI exhibit major absorptions upon visible-light, indicating the dual role of hydrazone as both ligand and photocatalyst in this reaction.
ADVANCED SYNTHESIS & CATALYSIS
(2022)
Article
Chemistry, Multidisciplinary
Pierfrancesco Maltoni, Gianni Barucca, Bogdan Rutkowski, Maria Chiara Spadaro, Petra E. Jonsson, Gaspare Varvaro, Nader Yaacoub, Jose A. De Toro, Davide Peddis, Roland Mathieu
Summary: The magnetic coupling of SrFe12O19/CoFe2O4 nanocomposites is investigated. The structural coherence and texture at the interfaces of the nanostructures are evidenced by advanced electron microscopy. The exchange intergranular interaction is evidenced and the critical thickness for uniform reversal of coupled interfaces is quantified.
Article
Biotechnology & Applied Microbiology
James C. Dykstra, Jelle van Oort, Ali Tafazoli Yazdi, Eric Vossen, Constantinos Patinios, John van der Oost, Diana Z. Sousa, Serve W. M. Kengen
Summary: This study demonstrates for the first time the feasibility of autotrophic short chain ester production from C1 carbon feedstocks using engineered microorganisms, and provides insights for future optimization of this approach.
MICROBIAL CELL FACTORIES
(2022)
Article
Chemistry, Physical
Yushan Xi, Yinhe Hai, Dawei Yao, Antai Li, Wenting Yang, Jing Lv, Yue Wang, Xinbin Ma
Summary: Zinc-doped copper silicate nanotube-assembled hollow sphere (NAHS) catalysts were prepared by a combination of hydrothermal and ion exchange method for the hydrogenation of methyl acetate (MA). By modulating the amount of zinc content, the catalyst exhibited excellent catalytic performance even at low H2/MA ratio. The enrichment of H2 by NAHS nanoreactor and the effect of zinc modification were discussed.
MOLECULAR CATALYSIS
(2022)
Article
Nanoscience & Nanotechnology
Jingze Li, Jiaxin Ma, Liu Hong, Cheng Yang
Summary: This study successfully decorated copper nanoparticles on molybdenum disulfide nanosheets, forming CuNPs/MoS2 composite with superior antibacterial performances. The synthesized composite demonstrated almost 100% bacterial kill towards both Gram-negative E. coli and Gram-positive S. aureus, and the bactericidal effect could last for at least 6 hours. The antibacterial properties of CuNPs/MoS2 were attributed to the synergism of photodynamic generated hydroxyl radical, oxidative stress without reactive oxygen species production and the release of Cu ions.
Article
Chemistry, Physical
Gheorghita Mitran, Shaojiang Chen, Dong-Kyun Seo
MOLECULAR CATALYSIS
(2020)
Article
Chemistry, Physical
Pranjali J. Naik, Puranjan Chatterjee, Shaojiang Chen, Wenyu Huang, Igor I. Slowing
Summary: Size-controlled Pd nanoparticles were successfully synthesized in the pores of mesoporous silica nanoparticles, showing higher catalytic activity in the Suzuki-Miyaura cross-coupling and hydrogenation reactions compared to larger nanoparticles. The enhanced activity can be attributed to the increased number of coordinatively unsaturated sites and higher back donation capacity of the smaller nanoparticles.
Article
Chemistry, Applied
Gheorghita Mitran, Shaojiang Chen, Kevin L. Dolge, Wenyu Huang, Dong-Kyun Seo
Summary: The study found that in the esterification reaction of cyclohexanol with propionic acid, the sample with the highest specific surface area, highest mesopore volume, and highest Bronsted acidity achieved the highest cyclohexyl propionate yield; whereas in the ketonic decarboxylation of propionic acid, the catalyst with the lowest ratio of Bronsted acid sites to Lewis acid sites exhibited the highest activity and selectivity.
MICROPOROUS AND MESOPOROUS MATERIALS
(2021)
Article
Biotechnology & Applied Microbiology
Gheorghita Mitran, Shaojiang Chen, Wenyu Huang, Dong-Kyun Seo
Summary: La-based zeolites have been studied for acetic acid conversion, with Bronsted acid sites promoting cyclohexyl acetate and acetone selectivity, while Lewis acidity favors acetone transformation into isobutene. The sample with the highest Bronsted acidity, La-H-13X, showed the highest activity for both reactions, indicating the importance of Bronsted acidity in the studied reactions.
JOURNAL OF CHEMICAL TECHNOLOGY AND BIOTECHNOLOGY
(2021)
Article
Chemistry, Physical
Carla Casadevall, Haojie Zhang, Shaojiang Chen, Dayn J. Sommer, Dong-Kyun Seo, Giovanna Ghirlanda
Summary: The immobilization of Co-protoporphyrin IX (Co-PPIX) substituted cytochrome c (Co-cyt c) on Antimony-doped Tin Oxide (ATO) as a catalyst for photoelectrochemical oxidation of water was reported. The ATO-Co-cyt c photoanode exhibited significantly enhanced photocurrent density and good stability, demonstrating its potential for light-induced water oxidation.
Article
Energy & Fuels
Gheorghita Mitran, Adriana Urda, Octavian-Dumitru Pavel, Stefan Neatu, Mihaela Florea, Florentina Neatu
Summary: A series of cobalt-iron mixed oxides were synthesized and tested as catalysts for the oxidative decarboxylation of malic acid. The Co3Fe sample showed the highest conversion and yield, which could be attributed to the increased number of defects caused by the substitution of Co2+ for Fe3+.
BIOMASS CONVERSION AND BIOREFINERY
(2022)
Article
Chemistry, Multidisciplinary
Gheorghita Mitran, Tam Le Phuong Nguyen, Dong-Kyun Seo
Summary: In this study, CoAl2O4 samples were synthesized using sol-gel method with different complexing agents. The presence of oxalic acid as a complexation agent favors the expansion of Co3O4 phase. In the presence of citric acid as a complexing agent, CoAl2O4 is the dominant phase. The catalytic performances of CoAl2O4 spinel oxides were evaluated and showed good relationship with the Co3+/Co2+ ratio, reactants conversion, and products yield.
JOURNAL OF INDUSTRIAL AND ENGINEERING CHEMISTRY
(2022)
Article
Engineering, Chemical
Gheorghita Mitran, Luiza Izabela Jinga, Gianina Florentina Popescu-Pelin, Octavian Dumitru Pavel
Summary: The presence of tetrahedral sites leads to high selectivity towards pyruvic acid, while the presence of octahedral sites facilitates the further conversion of pyruvic acid into acetic acid with a high reaction rate.
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
(2022)
Article
Chemistry, Physical
Shaojiang Chen, Akalanka Tennakoon, Kyung-Eun You, Alexander L. L. Paterson, Ryan Yappert, Selim Alayoglu, Lingzhe Fang, Xun Wu, Tommy Yunpu Zhao, Michelle P. P. Lapak, Mukunth Saravanan, Ryan A. A. Hackler, Yi-Yu Wang, Long Qi, Massimiliano Delferro, Tao Li, Byeongdu Lee, Baron Peters, Kenneth R. R. Poeppelmeier, Salai C. C. Ammal, Clifford R. R. Bowers, Frederic A. Perras, Andreas Heyden, Aaron D. D. Sadow, Wenyu Huang
Summary: Non-reducible zirconia catalysts can efficiently hydrogenolytically cleave polyolefins, achieving similar activity as precious metal nanoparticles.
Article
Chemistry, Physical
Gheorghita Mitran, Stefan Neatu, Octavian Dumitru Pavel, Adriana Urda, Anca G. G. Mirea, Mihaela Florea, Florentina Neatu
Summary: Iron-doped Co3O4 oxides prepared by a surfactant-assisted method showed good catalytic activity in malic acid conversion, with oxygen defects and the presence of Co2+ playing a key role in catalyst activation for pyruvic acid production. The most active catalyst, with a conversion rate of 70% for malic acid and a yield of 24% for pyruvic acid, had an inverse spinel structure and a low band-gap. The catalyst with the highest Co2+ loading exhibited the highest yield of pyruvic acid.
CATALYSIS SCIENCE & TECHNOLOGY
(2023)
Article
Chemistry, Multidisciplinary
Gheorghita Mitran, Tam Le Phuong Nguyen, Dong-Kyun Seo
Summary: This study synthesized CoAl2O4 spinel using the sol-gel method with different solvents and precursors. The structure and optical properties were characterized through various analyses. The presence of excess aluminum in catalysts synthesized with methanol and butanol as solvents resulted in decreased activity in the lactonization reaction. The active sites in the dehydrocyclization reaction were confirmed to be Co3+ sites and oxygen vacancies.
REACTION CHEMISTRY & ENGINEERING
(2023)
Article
Engineering, Electrical & Electronic
Akanksha Singh, Sarthak Mandal, Shaojiang Chen, Minghui Liu, Christopher J. Gisriel, Anne-Marie Carey, Hao Yan, Dong-Kyun Seo, Su Lin, Neal W. Woodbury
Summary: A biohybrid electronic system has been developed with a photosystem I (PSI) fixed on a porous antimony-doped tin oxide electrode, resulting in light-powered reduction of NADPH. Cytochrome c was used to orient PSI reaction centers and transport electrons, generating a photocurrent. Despite attempts to catalyze dye reduction by NADPH, dye reduction occurred even without enzymes, with direct light-dependent reduction of NADPH and subsequent reduction of resazurin.
ACS APPLIED ELECTRONIC MATERIALS
(2021)
