Article
Chemistry, Physical
Tomoyuki Hirano, Takama Tsuboi, Eishi Tanabe, Takashi Ogi
Summary: Metal oxide supports have attracted attention in improving the performance of fuel cells. In this study, niobium-doped tin oxide nanoparticles were synthesized with a network structure and platinum catalysts were deposited on them. The study evaluated the effect of different particle formation processes on the structure of the flame-made Pt/NTO particles. The flame spray pyrolysis method was found to produce NTO with uniformly dispersed Pt, and the resulting particles showed high electrochemical surface area and mass activity values.
JOURNAL OF ALLOYS AND COMPOUNDS
(2022)
Article
Nanoscience & Nanotechnology
Martin T. Matter, Leonida Maliqi, Kerda Keevend, Stefanie Guimond, Judith Ng, Efe Armagan, Markus Rottmar, Inge K. Herrmann
Summary: Dental implant failure is a prevalent issue globally, with current surface modifications facing challenges in achieving sufficient integration and preventing biofilm formation. Introduction of nanostructures on the surface shows promise in improving implant-tissue contact, but existing coating processes are limited in versatility and cost. A highly modular single-step method has been developed to produce multicomponent porous bioactive nano-structured coatings on implants, with potential applications in dental implantology and beyond.
ACS APPLIED MATERIALS & INTERFACES
(2021)
Article
Thermodynamics
M. F. B. Stodt, Jan Derk Groeneveld, Lutz Maedler, Johannes Kiefer, Udo Fritsching
Summary: This study investigates the occurrence of in-flight droplet microexplosions (mu-explosions) during flame spray pyrolysis and confirms the findings through single drop experiments. It is found that there are distinct mu-explosions happening at high frequencies during the synthesis of iron oxide nanoparticles. This finding is significant for understanding the role and relevance of mu-explosions in the production and formulation of functional nanoparticles.
COMBUSTION AND FLAME
(2022)
Article
Chemistry, Physical
Gian Luca Chiarello, Massimo Bernareggi, Elena Selli
Summary: In this study, in situ modulated excitation X-ray absorption spectroscopy (ME-XAS) was used to investigate the role of Pt and Cu nanoparticles (NPs) in TiO2 photocatalysis. The results show that Pt NPs act as active sites for H2 evolution, while Cu NPs exhibit different oxidation states and undergo redox switching under aerobic conditions.
Article
Engineering, Environmental
Shuo Liu, Mohammad Moein Mohammadi, Mark T. Swihart
Summary: This review provides an overview of flame aerosol synthesis of catalysts, including the mechanisms, applications, and recent progress. By controlling process parameters and reactor configuration, catalyst structures can be tailored. The advantages, limitations, and future research directions of flame-made catalysts are also discussed in the review.
CHEMICAL ENGINEERING JOURNAL
(2021)
Article
Engineering, Chemical
R. Tischendorf, M. Simmler, C. Weinberger, M. Bieber, M. Reddemann, F. Froede, J. Lindner, H. Pitsch, R. Kneer, M. Tiemann, H. Nirschl, H-J Schmid
Summary: This study investigates the flame spray pyrolysis setup and particle extraction methods, examining the impact of different precursor formulations on particle formation pathways. Results show that an acidic precursor solution leads to gas-to-particle conversion, while the absence of acid results in a droplet-to-particle pathway. Customized extraction techniques enable in situ research on particle structure evolution.
JOURNAL OF AEROSOL SCIENCE
(2021)
Article
Chemistry, Analytical
K. Khamfoo, A. Wisitsoraat, M. Punginsang, A. Tuantranont, C. Liewhiran
Summary: Nb-doped SnO2 nanoparticles were synthesized via flame spray pyrolysis for the first time, with 0.5 wt% Nb content providing the best sensor response to 1 vol% C2H2 at 350 degrees Celsius. The sensor also exhibited low humidity dependence, good long-term stability, and high C2H2 selectivity.
SENSORS AND ACTUATORS B-CHEMICAL
(2021)
Article
Chemistry, Analytical
K. Inyawilert, A. Sukee, M. Siriwalai, A. Wisitsoraat, J. Sukunta, A. Tuantranont, S. Phanichphant, C. Liewhiran
Summary: Erbium-doped SnO2 nanoparticles with different Er concentrations were synthesized and their gas-sensing properties were investigated. The sample with 0.1 wt% Er exhibited the best response to C2H4O, showing significantly improved performance compared to the undoped sample.
SENSORS AND ACTUATORS B-CHEMICAL
(2021)
Article
Energy & Fuels
Yihua Ren, Jinzhi Cai, Heinz Pitsch
Summary: Flame spray pyrolysis is a promising technology for synthesizing metal-oxide nanomaterials, but numerical simulation faces challenges. A single-droplet model has been developed to describe multicomponent droplet combustion and guide precursor and process design.
Article
Thermodynamics
Malte F. B. Stodt, Chenyang Liu, Shuiqing Li, Lutz Maedler, Udo Fritsching, Johannes Kiefer
Summary: This study investigates the flame spray pyrolysis of iron oxide nanoparticles using the new reference nozzle SpraySyn and applies the PS-LIBS technique to study particle formation under different precursor solutions. Significant differences in atomic emission spectra are observed when adding 2-ethylhexanoic acid to precursors, enabling differentiation between different particle formation routes. The experimental results provide deep insights into combustion and particle nucleation kinetics in spray flames, with potential applications for numerical simulations.
PROCEEDINGS OF THE COMBUSTION INSTITUTE
(2021)
Article
Engineering, Environmental
Xing Yuan, Lingquan Meng, Zuwei Xu, Chaohe Zheng, Haibo Zhao
Summary: The study investigated the influence of loading active copper components onto perovskites and essential operating parameters in flame aerosol synthesis to optimize the catalytic efficiency for the complete oxidation of lean CO and CH4. The CuO-SrTiO3 nanocatalysts exhibited optimal catalytic performance with precursor flow rate of 3 mL/min and CuO loading of 15 mol %. The excellent performance is attributed to the low-temperature reducibility of CuO quantum dots and metal-support interaction on SrTiO3 perovskite support.
ENVIRONMENTAL SCIENCE & TECHNOLOGY
(2021)
Article
Chemistry, Physical
Cecile Daniel, Yves Schuurman, David Farrusseng
Summary: The cerium-zirconium mixed oxides synthesized by Flame Spray Pyrolysis (FSP) exhibit higher catalytic activities compared to those prepared by precipitation method. It is suggested that FSP enables surface enrichment in cerium oxide interacting with zirconium oxide, leading to a higher concentration of adsorbed methanol at the surface, which explains the superior catalytic activity of the catalysts prepared using this method. This method is expected to generate mixed oxides with high surface area and different catalytic performances compared to those prepared at lower temperatures due to their metastable nature.
JOURNAL OF CATALYSIS
(2021)
Article
Materials Science, Multidisciplinary
Xuan Minh Chau Ta, Thi Kim Anh Nguyen, Anh Dinh Bui, Hieu T. T. Nguyen, Rahman Daiyan, Rose Amal, Thanh Tran-Phu, Antonio Tricoli
Summary: Photoelectrochemical water splitting is a promising approach to produce green hydrogen using solar energy. However, the lack of efficient photoanodes to catalyze the water photooxidation reaction remains a challenge. In this study, nanostructured FeWO4 photoanodes were synthesized on a fluorine doped tin oxide glass substrate via a scalable and ultra-fast flame synthesis route. The optimized FeWO4 photoanode with a bandgap of 1.82 eV and a FeOOH/NiOOH co-catalyst coating showed improved water photooxidation performance and good photostability, providing insights for the engineering of small band-gap catalysts for various photoelectrochemical applications.
ADVANCED MATERIALS TECHNOLOGIES
(2023)
Article
Chemistry, Multidisciplinary
Jun Mei, Tianwei He, Juan Bai, Dongchen Qi, Aijun Du, Ting Liao, Godwin A. Ayoko, Yusuke Yamauchi, Litao Sun, Ziqi Sun
Summary: The introduction of nanosized iridium (Ir) modifier and optimized exposed surfaces towards electrolytes leads to an efficient Ir-modified BP electrocatalyst with favorable adsorption energies towards catalytic intermediates, showing outstanding pH-universal water splitting performance surpassing most reported BP-based and commercial noble-metal catalysts.
ADVANCED MATERIALS
(2021)
Article
Energy & Fuels
Pavlos Psathas, Maria Solakidou, Asterios Mantzanis, Yiannis Deligiannakis
Summary: Pure-phase nanosized mullite-Bi2Fe4O9 nanoparticles prepared by Flame Spray Pyrolysis (FSP) technology demonstrate highly efficient O-2 production photocatalytic activity, surpassing previously reported Bi-Fe-O photocatalysts. The post-FSP annealing process affects the photoactivity of BiFeO3 and Bi2Fe4O9 in distinct ways, with Fe2+ centers in BiFeO3 significantly improving O-2 production efficiency.
Article
Green & Sustainable Science & Technology
Alexander Barke, Walter Cistjakov, Dominik Steckermeier, Christian Thies, Jan-Linus Popien, Peter Michalowski, Sofia Pinheiro Melo, Felipe Cerdas, Christoph Herrmann, Ulrike Krewer, Arno Kwade, Thomas S. Spengler
Summary: The use of novel battery technologies in short-haul electric aircraft supports the aviation sector's sustainable development goals, but the production of these batteries can have adverse environmental and socio-economic impacts. This paper investigates alternative technologies for lithium-sulfur all-solid-state batteries (LiS-ASSBs) in terms of their contribution to sustainable development goals (SDGs). The study applies a life cycle sustainability assessment approach to analyze four LiS-ASSB configurations and compares them to a benchmark lithium-sulfur battery with a liquid electrolyte. The results show that LiS-ASSB technologies generally have a positive contribution to SDG achievement, but the battery configuration with the best technical characteristics may not be the most promising in terms of SDG achievement. Sensitivity analysis reveals that the results are robust against weighting factors within the SDG quantification method.
JOURNAL OF INDUSTRIAL ECOLOGY
(2023)
Article
Chemistry, Physical
Bidyut Bikash Sarma, Jelena Jelic, Dominik Neukum, Dmitry E. Doronkin, Xiaohui Huang, Felix Studt, Jan-Dierk Grunwaldt
Summary: The structural changes of CeO2-supported single-atom catalysts (SACs) under reducing and oxidizing reaction atmospheres were studied. It was found that the changes in CO vibrational frequencies can indicate the oxidation state of the metals. Pt2+ and Pd2+ are more prone to cluster formation, while Rh3+ and Ru4+ remain as single sites.
JOURNAL OF PHYSICAL CHEMISTRY C
(2023)
Article
Chemistry, Physical
Xaver Lamprecht, Iman Evazzade, Iago Ungerer, Ludek Hromadko, Jan M. Macak, Aliaksandr S. Bandarenka, Vitaly Alexandrov
Summary: In this study, the degradation mechanisms of a model Na2Ni[Fe(CN)6] functional electrode in aqueous electrolytes are elucidated through density functional theory calculations and experiments. Besides solution pH and cation concentration, anion adsorption is identified as the main driving force for electrode dissolution. The nature of adsorbed anions can control the mass and charge transfer mechanisms during metal cation intercalation as well as the electrode degradation rate. The findings of this study provide practical guidelines for electrolyte optimization and can be extrapolated to the entire family of PBAs operating in aqueous media.
JOURNAL OF PHYSICAL CHEMISTRY C
(2023)
Review
Chemistry, Physical
Serhiy Cherevko
Summary: Modern proton exchange membrane water electrolyzers rely on noble metal electrocatalysts such as Ir and Pt, but the scarcity of these materials is a major drawback. Recent studies have explored non-noble metals as alternative electrocatalysts, although their activity and stability are still relatively low. This article reviews recent achievements in oxygen evolution electrocatalysis using non-noble metals and discusses five stabilization strategies. The authors also emphasize the importance of testing these electrocatalysts in real devices.
CURRENT OPINION IN ELECTROCHEMISTRY
(2023)
Article
Engineering, Environmental
Fabian Kubannek, Avital Zhegur-Khais, Songlin Li, Dario R. Dekel, Ulrike Krewer
Summary: We analyze the transport of anions in anion exchange membranes to understand the decarbonation process and its dynamics. The model covers the diffusive and migrative transport of water, carbonate anions, and hydroxide anions. The results reveal the factors affecting the decarbonation dynamics and provide insights into the properties of AEMs that are critical for electrochemical devices.
CHEMICAL ENGINEERING JOURNAL
(2023)
Article
Chemistry, Physical
Mohammad R. Nouri, Regina M. Kluge, Richard W. Haid, Jill Fortmann, Alfred Ludwig, Aliaksandr S. Bandarenka, Vitaly Alexandrov
Summary: A study shows that tunneling current fluctuations in electrochemical scanning tunneling microscopy (EC-STM) can map the electrocatalytic activity of surfaces with high spatial resolution. By using electron transport calculations, the study examines tunneling at Pt surfaces under the conditions of the oxygen reduction reaction. The results suggest that detecting reaction intermediates at electrified interfaces in operando conditions is possible based on tunneling noise amplitudes.
JOURNAL OF PHYSICAL CHEMISTRY C
(2023)
Article
Chemistry, Physical
Michail Gerasimov, Fernando A. Soto, Janika Wagner, Florian Baakes, Ningxuan Guo, Francisco Ospina-Acevedo, Fridolin Roeder, Perla B. Balbuena, Ulrike Krewer
Summary: Lithium metal batteries hold great promise for future energy storage, but the formation of a stable and efficient Solid Electrolyte Interphase (SEI) remains a challenge. This study utilizes a combination of molecular dynamics, density functional theory, and 3D-kinetic Monte Carlo simulations to analyze the internal species distribution and geometrical aspects of the native SEI. The simulations confirm the layered structure of the SEI and reveal the prevalence of corrosion processes in the formation of the SEI. This novel modeling approach provides valuable insights for improving battery performance and durability.
JOURNAL OF PHYSICAL CHEMISTRY C
(2023)
Article
Chemistry, Physical
David Bernhard, Thomas Kadyk, Sebastian Kirsch, Hannes Scholz, Ulrike Krewer
Summary: This work presents a model for predicting and analyzing voltage losses in proton exchange membrane fuel cells during accelerated stress testing. The model consists of two submodels - one describing the degradation of the catalyst active surface using a statistical physics-based approach, and another incorporating the degradation of catalyst activity. The model allows the description of catalyst surface reduction, changes in Tafel slope and exchange current density, and voltage losses.
JOURNAL OF POWER SOURCES
(2023)
Article
Energy & Fuels
Nico C. Roettcher, Yu-Ping Ku, Maria Minichova, Konrad Ehelebe, Serhiy Cherevko
Summary: In recent years, gas diffusion electrode (GDE) half-cell setups have attracted increasing attention in fuel cell research. This study compares three methods for determining the electrochemical active surface area (ECSA) of representative fuel cell catalysts and demonstrates that CO-stripping is the most convenient and reliable method in GDE setups. The application of underpotential deposition of copper (Cu-upd) also offers the possibility to derive the atomic surface ratio in PtRu-alloy catalysts.
JOURNAL OF PHYSICS-ENERGY
(2023)
Article
Nanoscience & Nanotechnology
Chiara Mazzariol, Francesca Tajoli, Alexander E. Sedykh, Paolo Dolcet, Jan-Dierk Grunwaldt, Klaus Muller-Buschbaum, Silvia Gross
Summary: Controlling the properties of inorganic materials, such as size, shape, and functional properties, is a main focus in material development. Confined reactions within nanoreactors have shown to have advantages over traditional methods in terms of control and uniformity. A study on calcium molybdate nanophosphors found that confinement in a miniemulsion approach resulted in more uniform size, shape, and doping effectiveness, leading to improved photoluminescence properties.
ACS APPLIED NANO MATERIALS
(2023)
Correction
Chemistry, Physical
Bidyut Bikash Sarma, Jelena Jelic, Dominik Neukum, Dmitry E. Doronkin, Xiaohui Huang, Sarah Bernart, Felix Studt, Jan-Dierk Grunwaldt
JOURNAL OF PHYSICAL CHEMISTRY C
(2023)
Article
Chemistry, Physical
Timo Fuchs, Valentin Briega-Martos, Jan O. Fehrs, Canrong Qiu, Marta Mirolo, Chentian Yuan, Serhiy Cherevko, Jakub Drnec, Olaf M. Magnussen, David A. Harrington
Summary: The initial step of electrochemical surface oxidation involves the extraction of metal atoms from their lattice sites to form a growing oxide. By conducting fast simultaneous electrochemical and in situ high-energy surface X-ray diffraction measurements, it has been demonstrated that the extraction of Pt atoms from Pt(111) is a fast process driven by potential, while the charge transfer for the formation of oxygen-containing species occurs at a much slower rate and appears to be decoupled from the extraction process. It is thus concluded that potential plays an independent and crucial role in electrochemical surface oxidation.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2023)
Article
Chemistry, Physical
Vasyl Marchuk, Xiaohui Huang, Jan-Dierk Grunwaldt, Dmitry E. Doronkin
Summary: The influence of Pt particle size and structure on the catalytic performance in selective ammonia oxidation for emission control applications is poorly understood. In this study, operando XAS was used to complement traditional laboratory tests to determine the factors governing activity and selectivity in Pt catalysts with different particle sizes. It was found that the increase in activity with particle size was mainly due to the presence of favorable Pt ensembles on the surface. Spectroscopic data revealed different reaction mechanisms for particles above and below a size threshold of about 2 nm. The evolution of these mechanisms correlated with catalyst activity and selectivity change.
CATALYSIS SCIENCE & TECHNOLOGY
(2023)
Article
Chemistry, Multidisciplinary
L. Moriau, K. Stojanovski, P. Jovanovic, D. Escalera-Lopez, S. Cherevko, N. Hodnik
Summary: The utilization of iridium is expected to increase due to the rising implementation of water electrolyzer devices in the energy transition. However, its limited natural resources make recycling important. The most corrosion resistant platinum group metal, iridium, makes its recovery from waste difficult and energy-demanding. This study examines the impact of organics and chloride ions on the electrochemical dissolution of iridium for green recycling purposes.
Article
Chemistry, Multidisciplinary
Meng Yang, Jiafeng Yu, Anna Zimina, Bidyut Bikash Sarma, Jan-Dierk Grunwaldt, Habib Zada, Linkai Wang, Jian Sun
Summary: Converting CO2 into methanol is of great significance in the sustainable methanol economy. In this study, single-site Zr species in an amorphous SiO2 matrix were created by enhancing the Zr-Si interaction in Cu/ZrO2-SiO2 catalysts. It was found that CO2 preferentially adsorbs on the interface of Cu and single-site Zr, rather than on ZrO2 nanoparticles. Methanol synthesis was verified to occur on single-dispersed Zr sites, while the ordinary formate pathway occurred on ZrO2 nanoparticles. This work opens up new possibilities for understanding the role of atomically dispersed oxides in catalysis science.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)