Article
Chemistry, Physical
Ibrahim Gozeten, Kadir Karakas, Yasar Karatas, Mehmet Tunc, Mehmet Gulcan
Summary: This study focuses on the production of hydrogen from sodium borohydride in a methanolysis environment using ruthenium nanoparticles impregnated on a halloysite support material. The newly synthesized nanocatalyst showed excellent activity and reusability in the catalytic methanolysis reaction. The material analysis confirmed the homogeneous distribution of ruthenium nanoparticles on the support material. Kinetic studies were conducted to calculate the kinetic parameters and determine the rate equation for hydrogen production.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2023)
Article
Chemistry, Physical
Vishakha Kaim, Meenakshi Joshi, Matthias Stein, Sandeep Kaur-Ghumaan
Summary: Molecular hydrogen is a potential energy source for replacing fossil fuels in the future, and enzymatic systems provide inspiration for the design of novel catalysts. This study synthesized and characterized a new mononuclear ruthenium(II) complex, which showed remarkable catalytic activity for hydrogen production in the presence of acid.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2023)
Article
Energy & Fuels
Yuke Gao, Zhengkang Lu, Yang Hua, Yongqiang Liu, Changfa Tao, Wei Gao
Summary: This study investigates the radiation fraction of a turbulent diffusion jet flame using propane and hydrogen as fuel gases. It is found that the dilution effect of hydrogen on propane is limited, and the radiation fraction changes slightly with the increase in hydrogen flow rate.
Article
Thermodynamics
Tubagus Aryandi Gunawan, Marco Cavana, Pierluigi Leone, Rory F. D. Monaghan
Summary: This study analyzes the techno-economic model of a PBES system between Mellitah in Libya and Gela in Italy, exploring the feasibility and cost-effectiveness of hydrogen production system with different storage methods using PV electricity. The results indicate that PBESL with liquid hydrogen storage is more cost-effective than PBESC with compressed hydrogen storage.
ENERGY CONVERSION AND MANAGEMENT
(2022)
Article
Chemistry, Physical
Christopher A. Owen, Alessandro Podesta, Cristina Lenardi, Shima Kadkhodazadeh, Marcel Di Vece
Summary: Hydrogen is an attractive energy carrier due to its abundance, environmental friendliness, and highest known gravimetric energy density. Storing hydrogen as a magnesium hydride maximizes volumetric energy density and is an efficient and economically viable approach. However, the high temperature required for hydrogen release from magnesium has been a challenge. This study demonstrates a photo-stimulated hydrogen desorption method using magnesium nanoparticles, providing an effective and simple way for reversible hydrogen storage.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2022)
Article
Chemistry, Multidisciplinary
Pablo Molinillo, Bertrand Lacroix, Florencia Vattier, Nuria Rendon, Andres Suarez, Patricia Lara
Summary: In this study, it was found that RuSNS nanoparticles can catalyze the reduction of the greenhouse gas N2O to N-2 using different hydrosilanes.
CHEMICAL COMMUNICATIONS
(2022)
Article
Chemistry, Applied
Clement Maheu, Eric Puzenat, Pavel Afanasiev, Luis Cardenas, Christophe Geantet
Summary: This study investigated the influence of seven parameters on the photocatalytic production of hydrogen, including the optimal electron transfer from TiO2 to RuS2 at the rate-determining step. The photon yield showed an optimum at specific co-catalyst loading level, demonstrating the potential for optimizing electron transfer with incident photons having higher energy levels.
Article
Engineering, Chemical
Alexey Zhokh
Summary: Methane diffusion in large silica particles was experimentally investigated using the diffusion cell technique in pulse and saturation modes. The measured effective diffusivity was found to be in the order of 10-7 m2/s. The activation energy of methane diffusion obtained in pulse mode was 14 +/- 1 kJ/mol, while the saturation experiment gave an activation energy identical to 21 +/- 1 kJ/mol. These values are consistent with published data from adsorption experiments and molecular dynamic simulations. The observed kinetics reflects intra-particle diffusion-controlled desorption.
Article
Electrochemistry
Sergio Gonzalez-Poggini, Bruno Sanchez, Melanie Colet-Lagrille
Summary: Yttrium-doped copper tungstate photoelectrodes were prepared by dip coating yttrium-doped CuWO4 film on conductive glass substrates. The fabricated films were confirmed to have desired morphology and chemical composition. UV-vis diffuse reflectance measurements showed a bandgap of 2.30 eV for the pure CuWO4 photoelectrode, with a small shift to higher values for the yttrium-doped photoelectrodes due to increased electronic states in the first conduction band. The photoelectrochemical characterization demonstrated that yttrium doping resulted in enhanced charge separation and a significant increase (92.5%) in photocurrent density compared to the pure CuWO4 photoelectrode.
JOURNAL OF THE ELECTROCHEMICAL SOCIETY
(2023)
Article
Chemistry, Physical
Khulaif Alshammari, Turki Alotaibi, Majed Alshammari, Sultan Alhassan, Alhulw H. Alshammari, Taha Abdel Mohaymen Taha
Summary: The S@g-C3N4 and CuS@g-C3N4 catalysts were prepared using the polycondensation process and characterized using XRD, FTIR, and ESEM techniques. The S@g-C3N4 sample showed sharp and weak peaks at 27.2° and 13.01°, respectively, while the CuS reflections indicated a hexagonal phase. The interplanar distance decreased, promoting charge carrier separation and H-2 generation. FTIR data revealed structural changes in g-C3N4, and ESEM images showed a layered sheet structure for S@g-C3N4 and fragmented sheets for CuS@g-C3N4. BET data indicated a higher surface area in CuS-g-C3N4 nanosheets. UV-vis absorption and PL emission spectra showed changes after CuS growth on g-C3N4. The CuS@g-C3N4 catalyst exhibited improved hydrogen evolution performance and a lower activation energy than S@g-C3N4.
Article
Chemistry, Applied
Shin-ichiro Miyahara, Katsutoshi Sato, Yukiko Kawano, Kazuya Imamura, Yuta Ogura, Kotoko Tsujimaru, Katsutoshi Nagaoka
Summary: Research revealed that the alkalinity of supported Ru catalysts affects their activity in ammonia synthesis, with Ru/lanthanoid oxide catalysts exhibiting higher basicity and higher TOF. Hydrogen poisoning was significantly reduced in Ru/lanthanoid oxide catalysts, leading to a notable increase in ammonia synthesis rate.
Article
Chemistry, Physical
A. H. Balayeva
Summary: This work focuses on developing a mechanism to recover the mechanical energy lost during vehicle braking. A cable is used to extract the mechanical energy from the wheel braking system, which is connected to an additional element between the body and the rotating wheels. The mechanical energy is accumulated in a special spring system and converted into electrical energy by an electric generator.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2023)
Article
Optics
Mohamed Aazi, Damien Kinet, Claude Renaut, Johan Bertrand, Jean-Louis Auguste, Patrice Megret, Georges Humbert
Summary: Continuous measurements of the transmission spectrum of a fiber loop mirror interferometer composed of a Panda-type polarization-maintaining (PM) optical fiber during the diffusion of dihydrogen (H2) gas into the fiber are reported. The birefringence variation caused by H2 diffusion in the fiber is measured and correlated with simulation results, highlighting the strain distribution modification and its potential impact on the performance of fiber devices and H2 gas sensors.
Article
Chemistry, Physical
Xin Wei, Wei Zhang, Hanfeng Sun, Zeming Yuan, Qilu Ge, Yanghuan Zhang, Yan Qi
Summary: In this study, Mg95-xAl5Yx (x = 0-5) composites were successfully prepared to improve the sluggish kinetics and poor thermodynamics of Mg-based materials. The substitution of Y for Mg resulted in the formation of second phase Mg24Y5 and improved thermal stability. Additionally, the initial decomposition temperature of the Mg-Al-based alloy could be significantly reduced by the addition of yttrium.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2022)
Article
Polymer Science
Frank Welle
Summary: This study experimentally determined diffusion coefficients in GPPS and HIPS, analyzed the relationship between diffusion activation energy and pre-exponential factor, and established prediction parameters for diffusion coefficients.
Article
Chemistry, Physical
Diana Chaykina, Fahimeh Nafezarefi, Giorgio Colombi, Steffen Cornelius, Lars J. Bannenberg, Herman Schreuders, Bernard Dam
Summary: Thin films of rare earth metal oxyhydrides exhibit a photochromic effect, and the composition and encapsulation of the films can modify their band gap, crystal structure, photochromic contrast, and lifetime. The annealing process and defects are found to be crucial for the reversibility of the bleaching speed.
JOURNAL OF PHYSICAL CHEMISTRY C
(2022)
Article
Chemistry, Physical
Anirudh Venugopal, Laurentius H. T. Egberts, Jittima Meeprasert, Evgeny A. Pidko, Bernard Dam, Thomas Burdyny, Vivek Sinha, Wilson A. Smith
Summary: This study investigates the tuning of surface electronic properties of electrocatalysts through polymer modification, which allows for a shift in reaction selectivity. The introduction of stable Ni-CFx bonds at the nickel oxide/polymer interface leads to a transition from the oxygen evolution reaction towards hydrogen peroxide formation. The results highlight the possibility of modifying the surface electronic properties of electrocatalysts through stable polymer modification, providing an alternative pathway for tuning multipathway reactions in polymer/electrocatalyst environments.
ACS ENERGY LETTERS
(2022)
Article
Materials Science, Multidisciplinary
Ziying Wu, Tom de Krom, Giorgio Colombi, Diana Chaykina, Gijs van Hattem, Henk Schut, Marcel Dickmann, Werner Egger, Christoph Hugenschmidt, Ekkes Bruck, Bernard Dam, Stephan W. H. Eijt
Summary: Rare-earth oxyhydride thin films exhibit a color-neutral, reversible photochromic effect. By investigating the lattice defects, electronic structure, and crystal structure of the films, we found the presence of cation monovacancies, vacancy clusters, and nanopores. The transition from a metallic to an insulating nature of the films and the formation of metallic domains were observed. In addition, the reversible formation of metallic nanodomains and the trapping of photoexcited electrons were proposed as possible explanations for the photochromic effect.
PHYSICAL REVIEW MATERIALS
(2022)
Correction
Chemistry, Physical
Diana Chaykina, Ismene Usman, Giorgio Colombi, Herman Schreuders, Beata Tyburska-Pueschel, Ziying Wu, Stephan W. H. Eijt, Lars J. Bannenberg, Gilles A. de Wijs, Bernard Dam
Summary: The energy axes of the RBS and ERD data were initially underestimated, but the correction does not affect the data conclusions and peak assignments.
JOURNAL OF PHYSICAL CHEMISTRY C
(2022)
Article
Chemistry, Physical
Diana Chaykina, Ismene Usman, Giorgio Colombi, Herman Schreuders, Beata Tyburska-Pueschel, Ziying Wu, Stephan W. H. Eijt, Lars J. Bannenberg, Gilles A. de Wijs, Bernard Dam
Summary: In this study, the photochromic effect in rare-earth metal oxyhydride thin films was investigated through aliovalent doping of the RE cation. It was found that Ca doping influences the photochromic properties, leading to a lower photochromic contrast and a faster bleaching speed.
JOURNAL OF PHYSICAL CHEMISTRY C
(2022)
Article
Nanoscience & Nanotechnology
Lars J. Bannenberg, Herman Schreuders, Nathan van Beugen, Christy Kinane, Stephen Hall, Bernard Dam
Summary: In the future hydrogen economy, accurate, cost-efficient, and safe hydrogen sensors based on metal hydrides will be important. Alloying can tune the properties of hydrogen-sensing materials, as demonstrated by thin films of tantalum doped with ruthenium. The alloying effects include modifying the enthalpy of hydrogenation, shifting the pressure window for hydrogen absorption, and reducing the amount of hydrogen absorbed by the material, allowing for tunable sensitivity and a wide sensing range.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Nanoscience & Nanotechnology
Diana Chaykina, Giorgio Colombi, Herman Schreuders, Bernard Dam
Summary: Rare-earth metal oxyhydride thin films exhibit photochromism, causing reversible darkening when exposed to high-energy light. In this study, samarium oxyhydrides were included in the range of known photochromic RE-oxyhydrides. The properties of the Sm-oxyhydride film, such as optical bandgap, lattice constant, photochromic contrast, and bleaching speed, were controlled by the deposition pressure during reactive magnetron sputtering of SmH1.9+delta and post-oxidation. The slower bleaching speeds in Sm oxyhydrides compared to other lanthanides are attributed to the stability of the Sm2+ state and the difficulty in oxidizing it back to the original RE3+ state.
Article
Materials Science, Multidisciplinary
Giorgio Colombi, Bart Boshuizen, Diana Chaykina, Leyi Hsu, Herman Schreuders, Tom J. Savenije, Bernard Dam
Summary: Rare-earth oxyhydride thin films exhibit reversible photochromism and photoconductivity at ambient conditions, but the underlying mechanism and relationship are not clear. In this study, in situ time-resolved measurements of optical and transport properties were performed on Gd-based oxyhydride thin films to investigate this question. It was found that the initial mechanism of charge transport is p-type large polaron conduction; however, upon photo-darkening, a 10(4)-fold increase in conductivity occurs, and n-type carriers dominate. Furthermore, both photochromism and photoconductivity were shown to originate from a single process, as the photoconductivity is exponentially proportional to the increase in optical absorption. This exponential relationship suggests that the formation of optically absorbing species responsible for photochromism is accompanied by a concerted increase in negative charge carriers in the Gd oxyhydride films.
ADVANCED OPTICAL MATERIALS
(2023)
Article
Materials Science, Multidisciplinary
Lars J. Bannenberg, Larissa Blom, Kouji Sakaki, Kohta Asano, Herman Schreuders
Summary: Nanostructured metal hydrides have a crucial role in a hydrogen economy, as the nanostructuring or confinement of these materials significantly affects their structural and functional properties. We demonstrate that confining tantalum as a thin film extends its solubility limit, suppressing the phase transition observed in bulk upon hydrogenation. The continuous elastic deformation of the tantalum unit cell with unequal lattice constants and angles ensures volumetric expansion in the out-of-plane direction, resulting in superb performance as a hysteresis-free optical hydrogen sensor over a wide hydrogen pressure/concentration range.
ACS MATERIALS LETTERS
(2023)
Article
Chemistry, Physical
Shrestha Banerjee, Diana Chaykina, Rens Stigter, Giorgio Colombi, Stephan W. H. Eijt, Bernard Dam, Gilles A. A. de Wijs, Arno P. M. Kentgens
Summary: Rare earth oxyhydrides REOxH(3-2x), with RE = Y, Sc, or Gdand a cationic FCC lattice, show reversible photochromic behavior. The efficiency of the photochromism is determined by the structural details and anion composition. In this study, NMR spectroscopy and DFT calculations are used to investigate the local environments, oxidation states, and dynamics of yttrium, hydrogen, and oxygen in YOxH(3-2x). The results suggest that the samples consist of domains with different hydride contents rather than a homogeneous anion mixing.
JOURNAL OF PHYSICAL CHEMISTRY C
(2023)
Letter
Multidisciplinary Sciences
Thomas Burdyny, Bernard Dam
Article
Materials Science, Multidisciplinary
Giorgio Colombi, Rens Stigter, Diana Chaykina, Shrestha Banerjee, Arno P. M. Kentgens, Stephan W. H. Eijt, Bernard Dam, Gilles A. de Wijs
Summary: In this study, the influence of O:H ratio on the formation, lattice energy, metastability, and optical properties of ROxH3-2x oxyhydrides was investigated using ab initio DFT. It was found that the anion-disordered phase showed comparable energy to the anion-ordered phase, especially in the H-rich composition range. The metastability of the anion-disordered phase depended on the cation size, with the CaF2-type structure becoming unstable above a certain H content. The electronic properties were studied using the modified Becke-Johnson scheme, and significant differences were observed between H-rich and O-rich oxyhydrides. The results suggest that anion-disorder is present in H-rich films, while some degree of anion ordering is observed in O-rich films. This study demonstrates a strategy to calculate the electronic/optical properties of materials with occupational disorder.
