Article
Geochemistry & Geophysics
Shenghua Wu, Jingwen Mao, Hong Yu, Daorong Tan, Xinxia Geng
Summary: The study of TiO2 polymorphs in the Dongyuan gold veins in South China provides important insights into the temperature range for early mineral precipitation and suggests that ore-forming fluids originated from deeper and hotter crustal levels in the shallow crust.
AMERICAN MINERALOGIST
(2021)
Article
Chemistry, Multidisciplinary
Ying Feng, YongChao Zhu, Tian Chen, Pengcheng Li, Bingjie Liu, Jianfeng Cai, Wenjie Liang, Hai Xu
Summary: Weakly crystalline TiO2 with high catalytic activity was prepared using a simple green chemical oxidation reaction at low temperatures, achieving significant degradation of methylene blue and isopropyl alcohol.
NEW JOURNAL OF CHEMISTRY
(2024)
Article
Chemistry, Physical
M. T. Colomer, E. Rodriguez, M. Moran-Pedroso, F. Vattier, A. de Andres
Summary: Novel Tb-doped TiO2 hollow spheres (HSs) have been synthesized for the first time in the range of 0.0-2.0 at.%, revealing a significant impact of Tb presence and morphology on the anatase-to-rutile transition temperature. Contrary to expectations, Tb doping reduces the transition temperature and favors rutile phase formation in HSs. XPS measurements confirm the presence of Tb3+ and Tb4+ in both HSs and NPs, with Tb4+ contributing to weakened f-f emission intensity and destabilization of the anatase phase.
JOURNAL OF ALLOYS AND COMPOUNDS
(2021)
Article
Chemistry, Multidisciplinary
Olufemi Olatidoye, Daria Thomas, Bishnu Prasad Bastakoti
Summary: A facile method of synthesizing mesoporous TiO2 thin films using polymeric micelles as a template is reported. The mesoporous TiO2 films showed enhanced photocatalytic activity due to increased surface area and rough surface around the pores. Photocatalytic testing demonstrated the effectiveness of the prepared mesoporous thin films in degrading dyes.
NEW JOURNAL OF CHEMISTRY
(2021)
Article
Materials Science, Multidisciplinary
Galina A. Zenkovets, Alexey A. Shutilov, Vladimir Yu Gavrilov
Summary: Thermally stable nanocomposites TiO2 with anatase structure doped with ceria or yttria were successfully synthesized using a special precursor of titania and impregnation method. The dopants used in this research increased the temperature of anatase to rutile transition and stabilized the anatase phase up to 900 degrees C. The obtained composites showed high surface area and uniform pore diameter at high temperatures, with the ceria-doped composite demonstrating high catalytic activity for CO oxidation at relatively low temperatures.
MATERIALS RESEARCH BULLETIN
(2022)
Article
Chemistry, Multidisciplinary
Xiaobing Wang, Yihao Zhang, Yu Cao, Zhi Zheng, Xiaowei Guo, Jiabao Cui, Xiangdong Lou, Yuming Guo, Huijun Liang, Zhansheng Lu, Lin Yang, Hua Zhang, Xiaoming Ma
Summary: The novel tufted nanoneedle embedded localized microsphere (TELM) nanoarchitecture has been proposed and successfully synthesized. The TELM is composed of tufted rutile TiO2 nanoneedles embedded on the localized surface of anatase TiO2 microspheres (TiO2-TELM). The decay lifetime of photogenerated charge carriers (PCCs) in TiO2-TELM is significantly prolonged compared to pure rutile and anatase TiO2, and the TiO2-TELM with 1 wt% Pd loading achieves an ultrahigh H-2 production rate in pure water. Moreover, the photogenerated electrons and holes in TiO2-TELM migrate towards the rutile and anatase phases of TiO2, respectively. This study provides an effective strategy for the rational design and controlled synthesis of nanoarchitectures.
MATERIALS CHEMISTRY FRONTIERS
(2023)
Article
Chemistry, Physical
Ji Young Hwang, Gun-hee Moon, Bupmo Kim, Takashi Tachikawa, Tetsuro Majima, Seungwoo Hong, Kangwoo Cho, Wooyul Kim, Wonyong Choi
Summary: The generation of mobile free OH radicals on anatase through a reductive conversion of dissolved O2 is crucial in achieving the mineralization of non-adsorbing substrates, while surface trapped holes lead to the generation of surface-bound OH radicals on both anatase and rutile. Understanding the production pathway of OH radicals in photocatalysis will help optimize their generation for efficient photocatalytic oxidation of pollutants.
APPLIED CATALYSIS B-ENVIRONMENTAL
(2021)
Article
Chemistry, Physical
Luong Xuan Dien, Toru Murayama, Nguyen Tuan Hung, Quang Duc Truong, Huynh Dang Chinh, Masamichi Yoshimura, Masatake Haruta, Tamao Ishida
Summary: Gold nanoparticles supported on titania catalysts were prepared using the solid grinding method, and the catalytic activity was improved by treatment with potassium tert-butoxide. The catalyst exhibited high catalytic activity and stability for CO oxidation.
JOURNAL OF CATALYSIS
(2022)
Article
Chemistry, Applied
P. Rychtowski, B. Tryba, D. Baranowska, B. Zielinska, H. Nishiguchi, M. Toyoda
Summary: Reduction of TiO2 has been studied under different conditions. The addition of ammonia solution followed by hydrothermal treatment and calcination in Ar resulted in the formation of surface defects such as hole traps and oxygen vacancies in the reduced TiO2. Heat-treatment under hydrogen gas produced the highest amount of reduced Ti3+ centers, leading to improved water splitting and enhanced photocatalytic properties. Hydrogen was found to be a stronger reducing agent than ammonia gas.
Article
Chemistry, Physical
Ailin Cui, Pengwei Ren, Yang Bai, Hongying Yu, Huimin Meng Resource
Summary: The study investigates the performance of composite Pt/TiO2-CNx catalysts with different TiO2 anatase/rutile phases synthesized by ethylene glycol reduction. Results show that the size of Pt nanoparticles significantly affects HOR activity, and the activity of Pt/TiO2-CNx catalysts is influenced by the TiO2 phase content.
APPLIED SURFACE SCIENCE
(2022)
Article
Chemistry, Multidisciplinary
Carla Calabrese, Amelie Maertens, Alessandra Piras, Carmela Aprile, Leonarda Francesca Liotta
Summary: TiO2 nanomaterials were synthesized through a sol-gel method using titanium butoxide as a precursor, Pluronic F127 as a template, toluene as a swelling agent, and acidic water or ethanol as reaction solvents. The synthesis medium influenced the phase composition of the solids, with ethanol promoting dispersed anatase particles and water leading to a rutile phase. The photocatalytic activity of the samples was tested by the photodegradation of Rhodamine B.
Article
Chemistry, Multidisciplinary
Suhail Mubarak, Duraisami Dhamodharan, Hun-Soo Byun, S. B. Arya, Deepak K. Pattanayak
Summary: The necessity to limit the high concentration of CO2 in the atmosphere due to global warming has led to the development of photoelectrochemical CO2 reduction methods. In this study, a cost-effective 3D nanoporous structured TiO2 nanoparticles were fabricated, with the TO600 sample showing the lowest CO2 reduction onset potential under light conditions.
JOURNAL OF CO2 UTILIZATION
(2022)
Article
Physics, Applied
Nhan V. Nguyen, Nam Nguyen, Jason R. Hattrick-Simpers, Oleg A. Kirillov, Martin L. Green
Summary: Transparent conducting oxides have high optical transmittance and are electrically conductive, with differences in optical responses between materials such as TiO2, ZnO, and SnO2. The bandgap and electronic characteristics were determined and discussed in this study.
APPLIED PHYSICS LETTERS
(2021)
Article
Chemistry, Multidisciplinary
Suhail Mubarak, Duraisami Dhamodharan, Hun-Soo Byun, S. B. Arya, Deepak K. Pattanayak
Summary: In this study, cost-effective and novel 3D nanoporous structured TiO2 nanoparticles were fabricated for photoelectrochemical reduction of CO2. The samples prepared at 600 degrees C exhibited the highest photocurrent density and the lowest CO2 reduction onset potential.
JOURNAL OF CO2 UTILIZATION
(2022)
Article
Chemistry, Applied
Vladimir Paunovic, Marcos Rellan-Pineiro, Nuria Lopez, Javier Perez-Ramirez
Summary: This article investigates the activity of TiO2-rutile and TiO2-anatase polymorphs in the catalytic HBr oxidation, with the results showing that rutile exhibits higher activity than anatase, indicating that HBr oxidation follows a defect-driven mechanism.
Article
Chemistry, Multidisciplinary
Anastasiya Kutuzova, Tetiana Dontsova, Witold Kwapinski, James J. Leahy, Jennifer Strunk
Summary: TiO2 nanoparticles synthesized by sol-gel and hydrothermal methods showed good photocatalytic removal efficiency for antibiotics under UVA light. The sol-gel synthesized sample exhibited higher crystallinity but lower specific surface area, while the hydrothermal synthesized sample had a higher specific surface area.
MOLECULAR CRYSTALS AND LIQUID CRYSTALS
(2023)
Article
Physics, Applied
Simon Kreuznacht, Maximilian Purcel, Simon Boeddeker, Peter Awakowicz, Wei Xia, Martin Muhler, Marc Boeke, Achim von Keudell
Summary: This study investigates hydrogen production through plasma methane pyrolysis using a microwave plasma torch (MPT) and a gliding arc plasmatron (GAP). The performance of the two plasma sources is compared in terms of methane conversion, product spectrum, and energy efficiency. The physical and chemical properties of the produced carbon particles are also compared. The results show that the methane conversion is higher in the GAP compared to the MPT. Amorphous spherical carbon particles are produced in the volume of the plasma source in the MPT, while in the GAP, methane pyrolysis stops after the production of acetylene and the conversion of acetylene into solid carbon takes place on top of the electrode surfaces, leading to different characteristics of the carbon particles.
PLASMA PROCESSES AND POLYMERS
(2023)
Article
Chemistry, Physical
Duoyue Tang, Zewen Shen, Sebastian Lechler, Guilong Lu, Ling Yao, Yezi Hu, Xiubing Huang, Martin Muhler, Guixia Zhao, Baoxiang Peng
Summary: In this study, an environmentally friendly catalytic approach using oxygen vacancies-enriched titanium-based oxides and water as solvent at room temperature for the lactonization of various aromatic and aliphatic diols was reported. The results showed that oxygen vacancies as strong Lewis acid sites played a pivotal role in the superior catalytic activities at room temperature, attributed to the enhanced reaction rate of the lactonization process.
JOURNAL OF CATALYSIS
(2023)
Article
Chemistry, Physical
Pascal Telaar, Stefan Schmidt, Patrick Diehl, Philipp Schwiderowski, Martin Muhler
Summary: MnxCo3-x[Co(CN)(6)](2) Prussian blue analogues were used to synthesize highly nitrogen- and oxygen-functionalized carbon catalyst precursors with embedded reduced Mn and Co species. These catalyst precursors exhibited good performance in CO hydrogenation to higher alcohols, showing the formation of primary and secondary alcohols, acetic acid, and propionaldehyde, indicating olefin hydration, carbonylation, and hydroformylation as reaction pathways. The obtained hydrocarbon fractions had a high olefinicity, making them suitable for olefin hydration and hydroformylation. Therefore, a unique class of multifunctional catalysts was obtained, bridging the gap between heterogeneous and homogeneous catalysis.
Article
Energy & Fuels
Till Eckhard, Christin Pflieger, Carmela Russo, Erik Freisewinkel, Tim Eisenbach, Jannik Boettger, Osvalda Senneca, Barbara Apicella, Martin Schiemann, Roland Span, Viktor Scherer, Martin Muhler, Francesca Cerciello
Summary: This paper investigates the changes in reactivity and physicochemical characteristics of char and tar produced from severe heat treatment in either inert or CO2-rich atmospheres of a synthetic fuel doped with Fe&Mg and K&Mg sulfates. The results show that mineral doping, heating rate, temperature, residence time, and atmosphere all interact and influence the pyrolysis products. Fe&Mg increased the light permanent gases during flash pyrolysis, and the minerals catalytically affected the decomposition of the levoglucosan fraction in the tars. The presence of CO2 during pyrolysis favored the aromatization of the chars, especially in combination with doped minerals.
Article
Chemistry, Physical
J. Geiss, J. Bueker, J. Schulte, B. Peng, M. Muhler, M. Winterer
Summary: The purpose of this study is to examine the structure and identify subtle changes of LaCo1-xFexO3 nanoparticles after catalysis. Small nanoparticles with varying iron content were synthesized and tested in cyclohexene oxidation. The crystal and local structure of the nanoparticles are investigated using X-ray and electron diffraction techniques. The catalytic activities of the cobalt-containing samples are significantly affected by changes in the local structure surrounding the cations in the perovskite phase.
JOURNAL OF PHYSICAL CHEMISTRY C
(2023)
Article
Chemistry, Physical
Benjamin Mockenhaupt, Philipp Schwiderowski, Jelena Jelic, Felix Studt, Martin Muhler, Malte Behrens
Summary: The active site of the industrially used Cu/ZnO catalyst for methanol formation is still controversial. Ammonia has been used as a probe molecule and it was found to inhibit methanol synthesis in CO2-containing synthesis gas. In this study, an industrial-type Cu/ZnO/Al2O3 catalyst was used to investigate poisoning effects. Injection of trimethylamine (TMA) and ammonia during steady-state methanol synthesis in a CO2/CO/H2 synthesis gas reversibly poisoned methanol formation, with ammonia showing stronger poisoning effect than TMA. DFT calculations provided a mechanism for ammonia poisoning, suggesting activation of ammonia on adsorbed oxygen or hydroxyl groups, followed by reaction with CO2 to form a stable carbamate on the active site.
JOURNAL OF PHYSICAL CHEMISTRY C
(2023)
Article
Electrochemistry
Bhawana Kumari, Michael Braun, Steffen Cychy, Ignacio Sanjuan, Gereon Behrendt, Malte Behrens, Martin Muhler, Corina Andronescu
Summary: In this work, the electrooxidation of solketal (SOR), acetal-protected glycerol, is explored over Cu-Co hydroxycarbonates to promote the formation of glycerol-derived C3 products and to limit Cu leaching from the catalyst. The competition between oxygen evolution reaction (OER) and SOR was evaluated, and the solketal de-acetalization as a function of potential was studied. The solketal/OH- ratio was found to affect the reaction selectivity.
Article
Chemistry, Multidisciplinary
Till Eckhard, Christin Pflieger, Jannik Boettger, Pascal Telaar, Francesca Cerciello, Martin Muhler
Summary: The catalytic effect of minerals on biomass conversion, with a focus on Fe and alkali/alkaline earth metals typically found in biomass minerals, was studied. A mineral-free reference hydrochar and a cellulose-based char material were systematically doped with sulfates of different metallic inorganic elements. Thermogravimetric reactivity measurements revealed Fe sulfate as one of the most active minerals, and alkali metal sulfates as more active than alkaline earth metal sulfates. Doping also influenced the carbon structural parameter. The derived parameters provide a comprehensive description of catalytic effects, taking into account the type of mineral, loading, atmosphere, and fuel morphology.
Article
Energy & Fuels
Jannik Boettger, Till Eckhard, Christin Pflieger, Osvalda Senneca, Martin Muhler, Francesca Cerciello
Summary: Hydrothermal carbonization (HTC) is a suitable thermochemical conversion process for waste biomass. The resulting hydrochar exhibits properties similar to solid fuels, making it attractive for co-firing. The study investigates two different biomasses and compares their hydrochars with untreated biomass and coal. The HTC process reduces cellulose/hemicellulose content and increases aromatic structures, heating value, and grindability, making it a potential source of green fuels for industrial boilers.
Article
Chemistry, Physical
Mariia Merko, Sara Delsing, G. Wilma Busser, Martin Muhler
Summary: The non-oxidative dehydrogenation of methanol to formaldehyde offers potential advantages including the production of anhydrous formaldehyde and valuable hydrogen by-products. Supported GaOx catalysts showed promising catalytic performance, with fumed SiO2 identified as the more suitable support. The loading of Ga and coke deposition affected the formaldehyde production rate and the generation of by-products.
JOURNAL OF CATALYSIS
(2023)
Article
Green & Sustainable Science & Technology
Michel Deitermann, Yannik Haver, Bastian Timo Mei, Martin Muhler
Summary: Continuous methanol photooxidation under mild conditions is a promising method to produce valuable chemicals and hydrogen. The selectivity of methanol oxidation to formaldehyde is primarily influenced by residence time and temperature. Temperature above 110 degrees C leads to catalyst deactivation and decreased formaldehyde selectivity. This study highlights the importance of understanding reaction conditions and the potential of selective photocatalytic gas-phase oxidation.
ADVANCED SUSTAINABLE SYSTEMS
(2023)
Correction
Chemistry, Multidisciplinary
Alexander Boeddecker, Arisa Bodnar, Lars Schuecke, Jonas Giesekus, Katja Wenselau, Ryan T. Nguyen-Smith, Timothy Oppotsch, Christian Oberste-Beulmann, Martin Muhler, Andrew R. Gibson, Peter Awakowicz
Summary: This article presents a scalable twin surface dielectric barrier discharge system for pollution remediation at high gas flow rates.
REACTION CHEMISTRY & ENGINEERING
(2023)
Article
Chemistry, Physical
Penghu Guo, Shuhua Zhang, Huicheng Cheng, Xingye Zeng, Hanlu Wang, Roland A. Fischer, Martin Muhler
Summary: As a detrimental pollutant, volatile organic compound (VOC) removal is a hot topic in research, and styrene oxidation is one of the focus areas. In this study, a series of hierarchically porous defect-engineered metal-organic frameworks (HP-DEMOFs) were prepared by in situ doping of 5-aminoisophthalic acid (5-NH2-H(2)ip) into a microporous Cu-BTC structure. These HP-DEMOFs exhibited significantly higher catalytic activity in the styrene oxidation reaction compared to the microporous Cu-BTC structure.
CATALYSIS SCIENCE & TECHNOLOGY
(2023)
Article
Chemistry, Physical
Pascal Telaar, Patrick Diehl, Tim Herrendorf, Sven Schaefer, Wolfgang Kleist, Martin Muhler
Summary: The K content of Mn-Co-based catalysts for higher alcohol synthesis was successfully lowered by an additional washing step and substitution method. These methods changed the structural properties of the catalyst, increased CO conversion, and improved the selectivity of primary and secondary alcohols.
CATALYSIS SCIENCE & TECHNOLOGY
(2023)
