Article
Chemistry, Multidisciplinary
Matias Alvear, Marie-Louis Reich, Kari Era''nen, Stefan Haase, Dmitry Yu. Murzin, Tapio Salmi
Summary: Epoxidation of butane isomers (1-butene and isobutene) on a commercial titanium silicate catalyst (TS-1) was studied in a trickle bed reactor using the transient step response technique. The study revealed different dynamics of product formation between the isomers. The molecular structure of the isomers impacted both the transient and stationary states of the system, with 1-butene displaying a dynamic behavior and isobutene behaving similarly to ethene and propene.
Article
Chemistry, Multidisciplinary
Chenhao Li, Ning Pu, Kaimeng Huang, Changjiu Xia, Xinxin Peng, Min Lin, Bin Zhu, Xingtian Shu
Summary: This study developed a novel catalyst, CoOx/h-S-1, by loading CoOx nanoparticles within the internal channels of hierarchical silicalite-1 zeolite. This catalyst exhibited promising catalytic activity and lifetime in the aerobic co-oxidation reaction, with high selectivities of epoxide and carboxylic acid. The study also revealed the importance of loaded CoOx nanoparticles in enhancing radical initiation, transformation, and oxygen transfer, and provided fundamental understanding for the rational design of catalysts and the development of process technology.
Review
Engineering, Chemical
Guanghui Zhao, Xuliang Deng, Dong Lin, Jincheng Liu, Yong-jun Zhang, Yibin Liu, Xiaobo Chen, Xiang Feng, De Chen, Chaohe Yang, Honghong Shan
Summary: This review provides a comprehensive summary of the state-of-the-art synthetic strategies of high-efficient Ti sites in TS-1 for alkene epoxidation. It discusses the improvement mechanisms and epoxidation mechanisms of these strategies. The current limitations and future perspectives on the development of eco-sustainable alkene epoxidation are also analyzed.
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
(2023)
Article
Energy & Fuels
Tong Zhang, Xuejing Chen, Bingjie Ding, Zuoji Ding, Yajun Wang, Hewen Qiu, Yongjun Jiang, Sheng Dai, Zhenshan Hou
Summary: In this study, a new kind of carboxylic acid-functionalized imidazolium-based ionic liquid-stabilized Ti oxoclusters was synthesized via solvothermal method, and the structure and performance were examined. The results indicated that the Ti oxoclusters exhibited excellent catalytic activity and stability in the oxidative desulfurization process. Furthermore, the anion in the ionic liquid played a crucial role in the activation of catalytic species.
Article
Chemistry, Physical
Qiaoyun Qin, Hongxia Liu, Yanke Guo, Baohe Wang, Jing Zhu, Jing Ma
Summary: The solvolysis mechanism of propylene oxide (PO) over TS-1 catalyst with tetrahedral Ti and Ti/defect sites was investigated using a quantum mechanical/molecular mechanics (QM/MM) approach. The results showed that the ring-opening ability of active sites is crucial for the activity of PO solvolysis. The stepwise mechanism via PO ring opening with 3MR Ti-OOH was found to be the dominant pathway at the Ti/defect site, while the concerted mechanism was dominant at the tetrahedral site for the formation of PPM.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2023)
Article
Chemistry, Physical
Myohwa Ko, Yongseon Kim, Jinwoo Woo, Boreum Lee, Rashmi Mehrotra, Pankaj Sharma, Jinjong Kim, Seon Woo Hwang, Hu Young Jeong, Hankwon Lim, Sang Hoon Joo, Ji-Wook Jang, Ja Hun Kwak
Summary: An integrated photo-electro-heterogeneous catalytic system for propylene epoxidation with O-2 is reported in this study, achieving stable production of propylene oxide for 24 hours with high selectivity under light irradiation. This system has the potential to produce chemical compounds in an environmentally benign manner.
Article
Engineering, Environmental
Zaiyong Yang, Zengxi Wei, Shunxin Zhou, Bo Bao, Shuangliang Zhao, Fuzhong Gong
Summary: This study reports a new continuous DSHP process by constructing a feasible microreactor upon microfluidic chip under ambient condition, which achieved continuous production of H2O2 with high concentration. The study provides a promising on-site route to produce H2O2 in a green, safe yet ready-to-use process.
CHEMICAL ENGINEERING JOURNAL
(2023)
Article
Chemistry, Physical
Yunkai Yu, Jianhao Wang, Nan Fang, Zhen Chen, Dongxu Liu, Yueming Liu, Mingyuan He
Summary: This study investigates the kinetics of H2O2 activation catalyzed by various titanosilicates in different solvents, and concludes an isokinetic compensation effect. The solvent acts as a mediator to promote the proton transfer during the H2O2 activation process. The choice of solvent depends on the Ti active sites of the catalyst and their interaction with the solvent.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2023)
Article
Nanoscience & Nanotechnology
Juncong Yuan, Zhaoning Song, Dong Lin, Xiang Feng, Yongxiao Tuo, Xin Zhou, Hao Yan, Xin Jin, Yibin Liu, Xiaobo Chen, De Chen, Chaohe Yang
Summary: In this work, a facile and mesoporogen-free strategy was reported to manipulate the pore structure and particle size of TS-1 using a concentrated system. The novel TS-1 showed higher Ti concentration on surface, higher surface area, abundant mesopores, and reduced crystal size, leading to a good PO formation rate with enhanced catalytic stability as a bifunctional Au-Ti catalyst.
ACS APPLIED MATERIALS & INTERFACES
(2021)
Article
Chemistry, Physical
Zhu Jin, Yifeng Liu, Liang Wang, Chengtao Wang, Zhiyi Wu, Qiuyan Zhu, Lingxiang Wang, Feng-Shou Xiao
Summary: In this study, AuPd nanoparticles fixed within aluminosilicate zeolite crystals were used as catalysts for the direct synthesis of H2O2 in aqueous solution. The zeolite-assisted proton transfer process catalyzed the oxygen hydrogenation to form H2O2, leading to high productivity and selectivity of H2O2 in water. The findings highlight the potential of zeolite fixed structures for designing efficient catalysts in H2O2 synthesis.
Article
Engineering, Chemical
Quanren Zhu, Cuilan Miao, Yanhui Yi, Chunyan Liu, Yitong Guo, Zhaochi Feng, Hongchen Guo
Summary: The industrial HPPO process suffers from energy-intensive and lengthy purification operations due to the use of CH3OH solvent. In this study, a solvent-free gas-phase epoxidation of propylene was achieved using a microspheric TS-1 catalyst and a fluidized bed reactor, resulting in high conversion rate and selectivity, as well as excellent stability attributed to the reactor design.
Article
Chemistry, Applied
Yoshihiro Kon, Takuya Nakashima, Yoshiki Makino, Hiroki Nagashima, Shun-ya Onozawa, Shu Kobayashi, Kazuhiko Sato
Summary: Continuous-flow epoxidation of aliphatic and aromatic alkenes using a fixed-bed liquid flow reactor equipped with a solid titanium silicalite-1 (TS-1) catalyst column and hydrogen peroxide (H2O2) as the oxidant was achieved. The developed flow reaction allowed for the continuous synthesis of 4-phenyl-1,2-epoxybutane with high yields (90%-98%) for 150 hours. By using a mixed solution of MeCN and MeOH, the reaction enabled the epoxidation of less-reactive long-chain terminal alkenes and multifunctional alkenes with good selectivity (78%-99%) and yields (12%-98%).
ADVANCED SYNTHESIS & CATALYSIS
(2023)
Article
Engineering, Chemical
Matias Alvear, Michele Emanuele Fortunato, Vincenzo Russo, Kari Eranen, Martino Di Serio, Juha Lehtonen, Sari Rautiainen, Dmitry Murzin, Tapio Salmi
Summary: The study demonstrated the effective and selective epoxidation of ethylene using TS-1 catalyst with hydrogen peroxide. Different experimental conditions led to the production of varying byproducts, confirming the catalyst's stability and selectivity.
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
(2021)
Article
Chemistry, Multidisciplinary
David S. S. Potts, Chris Torres, Ohsung Kwon, David W. W. Flaherty
Summary: Solvent molecules affect the free energies of species and intermediates during catalytic reactions, influencing rates and selectivities. In this study, the effects of different solvents in the epoxidation of 1-hexene with hydrogen peroxide over hydrophilic and hydrophobic Ti-BEA zeolites were examined. The results showed that higher mole fractions of H2O increased epoxidation rates and selectivities, while decreasing H2O2 decomposition rates. The differences in rates and selectivities were attributed to the stabilization of transition states within zeolite pores.
Article
Engineering, Chemical
Yanqi Guo, Zhihua Zhang, Jialun Xu, Xuezhi Duan, Xinggui Zhou
Summary: By using freeze-dried TS-1-B as a support, the dispersion of Au particles can be improved, allowing for uniform adsorption of Au precursors on TS-1-B and the formation of highly dispersed Au particles. As a result, the prepared Au/TS-1-B catalyst exhibits a significantly improved propylene oxide (PO) formation rate (around 240 gpo center dot h-1 center dot kgcat-1), along with high PO selectivity (approximately 92%) and hydrogen efficiency (approximately 41%).
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
(2023)
Article
Engineering, Chemical
Swen Lang, Michael Dyballa, Yvonne Traa, Deven Estes, Elias Klemm, Michael Hunger
Summary: This paper investigates both volatile and strongly adsorbed products of heavy hydrocarbon conversion on a zeolite using gas-phase and solid-state NMR techniques. The method involves conducting reactions in sealed glass tubes under vacuum to collect volatile reaction products, with a case study on pure 2-ethylphenol conversion on ultra-stabilized zeolite Y. This approach contributes to a better understanding of heavy hydrocarbon conversion under batch conditions.
CHEMIE INGENIEUR TECHNIK
(2021)
Article
Electrochemistry
D. Bentele, K. Aylar, K. Olsen, E. Klemm, S. H. Eberhardt
Summary: The study found that OER catalyst has a recovery effect on the anode during short-term recurring reversal operation, in contrast to findings from prolonged reversal accelerated stress tests (ASTs). Furthermore, combining different testing methods effectively distinguishes between catalyst and structural degradation, providing a basis for investigating anode degradation caused by cell reversal.
JOURNAL OF THE ELECTROCHEMICAL SOCIETY
(2021)
Article
Chemistry, Multidisciplinary
Armin Loewe, Maximilian Schmidt, Fabian Bienen, Dennis Kopljar, Norbert Wagner, Elias Klemm
Summary: Achieving high current densities and good formate faradic efficiency can be realized through a series of optimizations.
ACS SUSTAINABLE CHEMISTRY & ENGINEERING
(2021)
Article
Engineering, Chemical
Fabian Bienen, Joachim Hildebrand, Dennis Kopljar, Norbert Wagner, Elias Klemm, K. Andreas Friedrich
Summary: Electrochemical impedance spectroscopy (EIS) study of tin foil and SnOx/C gas-diffusions electrodes (GDEs) showed different wetting characteristics, with GDEs exhibiting significant time-dependent wetting behavior that should be normalized to evaluate reactivity based on wetted surface area.
CHEMIE INGENIEUR TECHNIK
(2021)
Article
Engineering, Chemical
Verena Schallhart, Heinrich Berthold, Elias Klemm, Lukas Moeltner
Summary: The study demonstrates that the direct heating method using a conductive hybrid ceramic substrate can significantly reduce the critical heat-up time after engine startup, enhancing emission reduction efficiency.
CHEMIE INGENIEUR TECHNIK
(2021)
Article
Chemistry, Multidisciplinary
Hang Liu, Hongguang Wang, Qian Song, Kathrin Kuester, Ulrich Starke, Peter A. Aken, Elias Klemm
Summary: A freestanding metal-organic layer with a 2D kagome dual lattice was successfully constructed, allowing uniform growth of Bi2O3 nanowires and exhibiting excellent CO2 electroreduction activity with high Faradaic efficiencies across a wide potential range. This post-synthetic modification strategy highlights the superiority of optimizing MOL-based composites for electrocatalysis.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Physical
Robin Himmelmann, Robin Otterstaetter, Oliver Franke, Stefan Brand, Olaf Wachsen, Gerhard Mestl, Franz Effenberger, Elias Klemm
Summary: The article presents a new one-step process for the selective oxidation of ethanol to ethylene oxide, without the need for an ethylene purification step. This process utilizes a dual-layer concept and achieves stable operation with high conversions and selectivities.
CATALYSIS COMMUNICATIONS
(2022)
Article
Chemistry, Physical
Dennis Beierlein, Dorothea Haeussermann, Yvonne Traa, Elias Klemm
Summary: A rapid aging method was developed to mimic the real aging of Ni/Al2O3 methanation catalysts in actual applications, resulting in catalysts with nearly constant conversion after hydrothermal deactivation at 600 or 700 degrees C. The catalytic performance of aged catalysts was comparable to long-term deactivated ones, indicating that long-term deactivation is caused by Ni particle sintering and support pores limiting Ni particle size.
Article
Chemistry, Multidisciplinary
Marvin Osskopp, Armin Lowe, Carlos M. S. Lobo, Sebastian Baranyai, Thulile Khoza, Michael Auinger, Elias Klemm
Summary: The electrochemical reduction of CO2 has the potential to become a key technology in the transformation to a sustainable circular carbon economy. However, current challenges in the process, such as the formation of formates instead of formic acid and the difficulty in operating at low pH values, make it unprofitable and costly for downstream processing. The carbonate problem, which reduces the carbon selectivity to faradaic products, is the main challenge. This study evaluates different cell configurations and demonstrates that an electrolyzer equipped with a single-layer gas diffusion electrode, a liquid electrolyte, and a zero-gap anode can achieve and sustain low pH values, paving the way for an industrial production of formic acid.
JOURNAL OF CO2 UTILIZATION
(2022)
Article
Engineering, Chemical
Elias Klemm, Carlos M. S. Lobo, Armin Loewe, Verena Schallhart, Stephan Renninger, Lara Waltersmann, Remi Costa, Andreas Schulz, Ralph-Uwe Dietrich, Lukas Moeltner, Vera Meynen, Alexander Sauer, K. Andreas Friedrich
Summary: The chemical industry needs to achieve carbon neutrality by 2050 by suppressing CO2 emissions from fossil sources. CHEMampere contributes to this goal by producing green chemicals using electricity-based CCU technologies in a decentralized manner.
CANADIAN JOURNAL OF CHEMICAL ENGINEERING
(2022)
Review
Biochemical Research Methods
M. Stoekl, N. J. Claassens, S. N. Lindner, E. Klemm, D. Holtmann
Summary: This article introduces the research on the conversion of carbon dioxide into chemical raw materials through electrochemical and microbial processes. Existing gaps for the realization of hybrid microbial electrosynthesis processes are evaluated.
CURRENT OPINION IN BIOTECHNOLOGY
(2022)
Review
Multidisciplinary Sciences
Theresa Jaster, Alina Gawel, Daniel Siegmund, Johannes Holzmann, Heiko Lohmann, Elias Klemm, Ulf-Peter Apfel
Summary: This review focuses on the current status of the chemical aspects of converting CO2 into multicarbon alcohols, including reaction routes, catalyst synthesis methods, and achievable product selectivities. It also discusses the impact of various factors on the reaction.
Review
Multidisciplinary Sciences
Alina Gawel, Theresa Jaster, Daniel Siegmund, Johannes Holzmann, Heiko Lohmann, Elias Klemm, Ulf-Peter Apfel
Summary: Efficient electrochemical conversion of CO2 into valuable chemical feedstocks requires well-coordinated interaction of all electrolyzer compartments, optimal matching of catalyst, cell setups, electrode design, membrane usage, and process parameters. This review aims to comprehensively summarize the current literature on how these aspects affect the overall performance of CO2 electrolysis and highlights the importance of CO2 supply and reaction product treatment for economic competitiveness and sustainable energy economy.
Article
Chemistry, Multidisciplinary
Mila Manolova, Joachim Hildebrand, Sebastian Hertle, Seniz Soergel, Holger Kassner, Elias Klemm
Summary: This publication investigates the selectivity and stability of bismuth (Bi)- and tin (Sn)-based electrocatalysts for the electrochemical CO2 reduction reaction (eCO(2)RR) to produce formate. The catalyst morphology was found to determine the performance of the electrode, with inhomogeneous deposits providing more active centres for eCO(2)RR and increasing the Faraday efficiency (FE) for formate. While complete Sn dissolution and deformation of the gas diffusion layer (GDL) were observed, no leaching of the electrodeposited Bi catalyst was observed, achieving an FE of 94.2% towards formate.
APPLIED SCIENCES-BASEL
(2023)
Article
Chemistry, Physical
Robin Himmelmann, Elias Klemm, Michael Dyballa
Summary: This study investigates the selective dehydration of ethanol over a silicotungstic acid (STA) catalyst supported on silica, demonstrating that a 36 wt% loading of STA provides maximum catalyst lifetime. Impregnation with CsOH effectively inhibits external Brønsted acid sites, prolonging catalyst lifetime and selectivity under industrially relevant conditions.
CATALYSIS SCIENCE & TECHNOLOGY
(2021)
