Article
Chemistry, Physical
Zhiyu Yi, Le Lin, Xuda Luo, Yanxiao Ning, Qiang Fu
Summary: Interfacial interaction between supported catalysts and the underlying substrate is crucial in catalysis. This study demonstrates that the interaction between Cr2O7 and Au can be weakened by applying an electric field, allowing for manipulation of the individual clusters. However, surface alloying with Cu enhances the interaction and makes the manipulation difficult.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2023)
Article
Chemistry, Physical
Marie E. Turano, Elizabeth A. Jamka, Maxwell Z. Gillum, K. D. Gibson, Rachael G. Farber, Weronika Walkosz, S. J. Sibener, Richard A. Rosenberg, Daniel R. Killelea
Summary: This passage discusses the high mobility of oxygen atoms on transition metal surfaces under demanding pressures and temperatures, leading to rapid surface diffusion, absorption into the subsurface, and reemergence on the surface. The unique role of subsurface oxygen atoms in the chemistry of oxidized metal catalysts is highlighted, but little is known about their formation and return to the surface. Additionally, localized changes in surface chemistry can occur due to oxygen diffusion between the surface and subsurface being mediated by defects.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2021)
Article
Chemistry, Physical
Alex C. Schilling, Nisa Ulumuddin, Volkan Cinar, Ryan T. Hannagan, Kyle Groden, Yicheng Wang, Laura A. Cramer, Paul L. Kress, Dipna A. Patel, Beverly Vo, Adrian Hunt, Phillip Christopher, Iradwikanari Waluyo, Jean-Sabin McEwen, E. Charles H. Sykes
Summary: The behavior and CO oxidation mechanisms of Rh single atoms and small clusters on the thin film 29 Cu2O grown on Cu(111) were studied using a surface science approach. It was found that Rh atoms and clusters coexist and enable low-temperature CO oxidation via different pathways, in contrast to Pt which is present solely as single atoms.
JOURNAL OF PHYSICAL CHEMISTRY C
(2022)
Article
Chemistry, Physical
Alex C. Schilling, Nisa Ulumuddin, Volkan Cinar, Ryan T. Hannagan, Kyle Groden, Yicheng Wang, Laura A. Cramer, Paul L. Kress, Dipna A. Patel, Beverly Vo, Adrian Hunt, Phillip Christopher, Iradwikanari Waluyo, Jean-Sabin McEwen, E. Charles H. Sykes
Summary: This study investigates the behavior of Rh single atoms and small clusters on the 29 Cu2O thin film using a surface science approach. Unlike Pt, Rh atoms and clusters coexist and enable low-temperature CO oxidation through different pathways. DFT calculations quantify the energetics of these pathways, while STM and XPS experiments confirm the findings.
JOURNAL OF PHYSICAL CHEMISTRY C
(2022)
Article
Chemistry, Physical
Huimin Wang, Huixia Fu, Peiwei You, Cui Zhang, Ying Jiang, Sheng Meng
Summary: In this study, the nonradiative recombination of electron-hole pairs on the rutile TiO2(110) surface was investigated using nonadiabatic dynamic simulations. It was found that the formation of polarons influenced the recombination rate, and the aggregation of oxygen vacancies accelerated polaron diffusion and prolonged the photocarrier lifetime.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2023)
Article
Chemistry, Physical
Eric M. Maxwell, Lyssa A. Garber, Clayton J. Rogers, Ava J. Galgano, Jordon S. Baker, Hasan Kaleem, David T. Boyle, Jessica L. Berry, Ashleigh E. Baber
Summary: Gold-based catalysts have attracted significant attention in heterogeneous catalysis due to their ability to catalyze reactions at low temperatures in oxidative environments. This study investigates the adsorption and intermolecular behavior of small alcohols on Au(111) defect sites, revealing distinct adsorption features and the linear relationship between desorption energy and carbon chain length. The study also highlights the influence of molecular packing structures on intermolecular interactions and the differences in adsorption energy at different sites.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2022)
Article
Materials Science, Multidisciplinary
Shuangxi Wang, Ping Zhang
Summary: In this study, the interaction between water and α-Pu 2 O 3 (111) surface was investigated using AIMD simulations. The results showed that water molecules can adsorb and dissociate on the surface, and the dissociation process is facilitated by hydrogen bonding interaction and hydrogen transfer reaction within the water clusters. These findings are important for understanding the corrosion of plutonium in a moist environment.
JOURNAL OF NUCLEAR MATERIALS
(2022)
Article
Chemistry, Physical
Francesco Cannizzaro, Sjoerd Kurstjens, Tom van den Berg, Emiel J. M. Hensen, Ivo A. W. Filot
Summary: Metal promoted indium oxide (In2O3) catalysts show promise for CO2 hydrogenation to methanol and carbon monoxide. The effect of metal dispersion on the methanol selectivity of In2O3 catalysts is debated, with the role of single metal atoms vs. metal clusters as catalysts being discussed. Density functional theory calculations were used to study the role of single atoms (SAs) of Ni, Pd, Pt, and Rh on In2O3(111) surface in CO2 hydrogenation to CO and methanol. Microkinetic simulations reveal that all SA models primarily catalyze CO formation through a redox pathway involving oxygen vacancies, explaining the negligible CH3OH selectivity due to higher barriers for formate intermediates hydrogenation compared to the overall barrier for the rWGS reaction.
CATALYSIS SCIENCE & TECHNOLOGY
(2023)
Article
Materials Science, Coatings & Films
Elizabeth A. Jamka, Maxwell Z. Gillum, Christina N. Grytsyshyn-Giger, Faith J. Lewis, Daniel R. Killelea
Summary: Heterogeneously catalyzed reactions over transition metal surfaces play a crucial role in the chemical industry and global energy demand. CO oxidation is used to study the reactivity of various oxygenaceous surface phases, and surface IR spectroscopy provides valuable information about the reaction mechanism.
JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A
(2022)
Article
Chemistry, Physical
Bernhard von Boehn, Anton Weissbach, Jon-Olaf Krisponeit, Jan Ingo Flege, Jens Falta, Luca Gregoratti, Matteo Amati, Patrick Zeller, Ronald Imbihl
Summary: This study investigates the condensation of submonolayer coverages of V-oxide on Rh(111) into macroscopic stripes or islands during catalytic methanol oxidation. The phase separation within the VOx islands under reaction conditions is studied using various techniques, including PEEM, LEEM, mu LEED, and mu XPS. The dependence of the substructure on reaction conditions, V coverage, and island size is explored and the V coverages of different phases in the VOx islands are determined using mu XPS.
JOURNAL OF PHYSICAL CHEMISTRY C
(2022)
Article
Multidisciplinary Sciences
Wenfei Zhang, Yanbin Qi, Yuan Zhao, Wangxin Ge, Lei Dong, Jianhua Shen, Hongliang Jiang, Chunzhong Li
Summary: This study proposes a design strategy to regulate active hydrogen (Hads) production, achieving highly selective electrocatalytic conversion of biomass-derived 5-hydroxymethylfurfural (HMF) to 2,5-bis (hydroxymethyl)furan (BHMF). Rhodium (Rh) nanoparticles grown on Cu nanowires (RhCu NWs) catalyst is used, which accelerates water dissociation and facilitates Hads generation. The construction of an interfacial Hads-rich environment promotes the formation of BHMF and suppresses the formation of undesired dimers.
Article
Chemistry, Physical
Yang He, Xiong Zhao, Changfeng Chen, Haobo Yu
Summary: This study investigated the water adsorption and H2S dissociation processes on Fe (111) surface using computational methods. It was found that water molecules can influence the dissociation of H2S on the metal surface, providing insights into the H2S corrosion process.
APPLIED SURFACE SCIENCE
(2021)
Article
Chemistry, Physical
Arved C. Dorst, Friedrich Guethoff, Daniel Schauermann, Alec M. Wodtke, Daniel R. Killelea, Tim Schaefer
Summary: In this study, the researchers combined velocity map imaging (VMI) with temperature-programmed desorption (TPD) experiments to record the angular-resolved velocity distributions of recombinatively-desorbing oxygen from Rh(111). By matching the recorded distributions to the desorption temperature, they were able to assign the velocity distributions to desorption from specific surface and sub-surface states, providing insights into the recombinative desorption mechanisms and the availability of oxygen for surface-catalyzed reactions.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2022)
Article
Chemistry, Physical
Christine Pettersen, Anja O. Sjastad, Oleksii Ivashenko
Summary: The use of Pt-Rh catalysts is crucial in many industrial processes, requiring a solid understanding of their nanoscopic surface structure. By using scanning tunneling microscopy, the growth, elemental nanostructuring, and reconstruction behavior of various Pt-Rh near-surface alloys on fcc Rh(111) and Pt(111) were investigated. The findings provide insights for comparing with other homo/heteroepitaxial metal/fcc surfaces and offer a guide for producing tailor-made model catalytic surfaces.
JOURNAL OF PHYSICAL CHEMISTRY C
(2021)
Article
Chemistry, Physical
Yi-Cheng Huang, Hung-Yu Yen, Liang-Wei Lan, D. Dutta, A. Rahmah, Yu-Ling Lai, Yao-Jane Hsu, Chien-Cheng Kuo, Jeng-Han Wang, Meng-Fan Luo
Summary: The dissociation of water on Rh-O* clusters was studied, revealing that excess O* on small clusters promoted the dissociation of water, leading to an increase in hydroxyl (OH*) production. Furthermore, hydroxyl produced on Rh-O* clusters showed superior thermal stability compared to that on the Rh(111)(O*) surface.
JOURNAL OF CHEMICAL PHYSICS
(2021)
Article
Chemistry, Physical
J. M. Seymour, E. Gousseva, R. A. Bennett, A. I. Large, G. Held, D. Hein, G. Wartner, W. Quevedo, R. Seidel, C. Kolbeck, C. J. Clarke, R. M. Fogarty, R. A. Bourne, R. G. Palgrave, P. A. Hunt, K. R. J. Lovelock
Summary: Valence resonant X-ray photoelectron spectroscopy (RXPS) is a crucial tool for obtaining atomic contributions to valence states, while valence non-resonant X-ray photoelectron spectroscopy (NRXPS) provides a direct method for probing the overall valence electronic structure. This work combines RXPS with NRXPS and density functional theory calculations to validate the use of RXPS in identifying atomic contributions for various solutes and solvents. RXPS has the potential to serve as a promising fingerprint method for identifying species in solution.
FARADAY DISCUSSIONS
(2022)
Article
Chemistry, Physical
Rosa Arrigo, Raoul Blume, Alexander Ian Large, Juan Jesus Velasco-Velez, Michael Haevecker, Axel Knop-Gericke, Georg Held
Summary: The electrocatalytic conversion of CO2 to fuels and chemicals using renewable energy is an important decarbonization technology. However, the performance of electrocatalysts reported so far is not yet satisfactory. This study investigates the in situ performance and interface chemistry of a Cu electrocatalyst under CO2 reduction conditions, using advanced material characterization techniques. The role of water in the formation of methanol from surface species is also demonstrated.
FARADAY DISCUSSIONS
(2022)
Article
Chemistry, Physical
Giulio D'Acunto, Roman Tsyshevsky, Payam Shayesteh, Jean-Jacques Gallet, Fabrice Bournel, Francois Rochet, Indiana Pinsard, Rainer Timm, Ashley R. Head, Maija Kuklja, Joachim Schnadt
Summary: The surface chemistry during the initial growth of atomic layer deposition plays a crucial role in the subsequent growth and quality of thin films. However, the understanding of this surface chemistry is still incomplete in many cases. In this study, we carried out an operando atomic layer deposition experiment to investigate the surface chemistry of HfO2 atomic layer deposition on SiO2 from an alkylamido-hafnium precursor and water. The results showed that the decomposition of the metal precursor on the stoichiometric SiO2 surface proceeds via a bimolecular reaction mechanism, leading to the formation of Hf-bonded methyl methylene imine and free dimethylamine.
CHEMISTRY OF MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Longxiang Liu, Liqun Kang, Arunabhiram Chutia, Jianrui Feng, Martyna Michalska, Pilar Ferrer, David C. Grinter, Georg Held, Yeshu Tan, Fangjia Zhao, Fei Guo, David G. Hopkinson, Christopher S. Allen, Yanbei Hou, Junwen Gu, Ioannis Papakonstantinou, Paul R. Shearing, Dan J. L. Brett, Ivan P. Parkin, Guanjie He
Summary: The electrochemical synthesis of hydrogen peroxide via a two-electron oxygen reduction reaction provides a promising alternative to the energy-intensive anthraquinone process. In this study, a highly active quinone-rich porous carbon catalyst was synthesized using a facile template-protected strategy. The optimized PCC900 material exhibited remarkable activity and selectivity for H2O2 production.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Engineering, Chemical
Chalachew Mebrahtu, Florian Krebs, Gianfranco Giorgianni, Salvatore Abate, Siglinda Perathoner, Gabriele Centi, Alexander I. Large, Georg Held, Rosa Arrigo, Regina Palkovits
Summary: Designing CO2 methanation catalysts that meet industrial requirements is still challenging. We report Ni-Fe hydrotalcite-derived catalysts with a wide range of Ni and Mg loadings showing that an optimised composition with Ni0.4 gives a very high CO2 conversion rate of 0.37 mmol/gcat/s at 300 degrees C. This catalyst is studied by in-situ APXPS and NEXAFS spectro- scopies and compared with the other synthesised samples to obtain new mechanistic in- sights on methanation catalysts active for low-temperature (300 degrees C) methanation, which is an industrial requirement. Under methanation conditions, in-situ investigations revealed the presence of metallic Ni sites and low nuclearity Ni-Fe species at xN; L (Ni loading)=21.2 mol%. These sites are oxidised on the low Ni-loaded catalyst(xN;L=9.2 mol%). The best CO2 conversion rate and CH4 selectivity are shown at intermediate xN;L (21.2 mol%), in the presence of Mg. These superior performances are related to the high metallic surface area, dispersion, and optimal density of basic sites. The TOFCO2(turnover frequency of CO2 con- version) increases exponentially with the fractional density of basic to metallic sites (XB) from 1.1 s-1(xN;L=29.2 mol%) to 9.1 s-1(xN;L=7.6 mol%). It follows the opposite trend of the CO2 conversion rate. In-situ DRIFTS data under methanation conditions evidence that the TOFCO2at high XB is related to the presence of a formate route which is not predominant at low XB (high xN; L ). A synergistic interplay of basic and metallic sites is present. This con- tribution provides a rationale for designing industrially competitive CO2 methanation cat- alysts with high catalytic activity while maintaining low Ni loading.(c) 2023 Institution of Chemical Engineers. Published by Elsevier Ltd. All rights reserved.
CHEMICAL ENGINEERING RESEARCH & DESIGN
(2023)
Article
Chemistry, Physical
Elan D. R. Mistry, Daphne Lubert-Perquel, Irena Nevjestic, Giuseppe Mallia, Pilar Ferrer, Kanak Roy, Georg Held, Tian Tian, Nicholas M. Harrison, Sandrine Heutz, Camille Petit
Summary: A family of boron nitride (BN)-based photocatalysts for solar fuel syntheses have recently emerged. Studies have shown that oxygen doping, leading to boron oxynitride (BNO), can extend light absorption to the visible range. This study demonstrates the importance of paramagnetic isolated OB3 states in inducing red-shifted light absorption and highlights the detrimental effects of diamagnetic O-B-O states on photochemistry in BNO semiconductors. The findings provide fundamental insights into the photophysics of BNO and pave the way for tailoring its optoelectronic and photochemical properties for solar fuel synthesis.
CHEMISTRY OF MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Jack E. N. Swallow, Elizabeth S. Jones, Ashley R. Head, Joshua S. Gibson, Roey Ben David, Michael W. Fraser, Matthijs A. van Spronsen, Shaojun Xu, Georg Held, Baran Eren, Robert S. Weatherup
Summary: The reactions of H-2, CO2, and CO gas mixtures on the surface of Cu at 200 ? were investigated using AP-XPS and AtmP-NEXAFS spectroscopy. The order of gas dosing plays a crucial role in the catalyst chemical state, with metallic Cu preserved when H-2 is introduced before CO2. The addition of CO is essential for removing adsorbed oxygen and activating CO2 on the Cu surface, facilitating methanol synthesis.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Multidisciplinary Sciences
Huihuang Fang, Simson Wu, Tugce Ayvali, Jianwei Zheng, Joshua Fellowes, Ping-Luen Ho, Kwan Chee Leung, Alexander Large, Georg Held, Ryuichi Kato, Kazu Suenaga, Yves Ira A. Reyes, Ho Viet Thang, Hsin-Yi Tiffany Chen, Shik Chi Edman Tsang
Summary: This study finds that atomically dispersed Ru atoms on polar (111) MgO surfaces show the highest rate of ammonia decomposition among all catalysts reported in literature. The strong metal-support interaction and efficient surface coupling reaction contribute to the high activity. The formation of Ru clusters/nanoparticles, however, decreases the catalytic performance.
NATURE COMMUNICATIONS
(2023)
Article
Chemistry, Physical
Diego Gianolio, Michael D. Higham, Matthew G. Quesne, Matteo Aramini, Ruoyu Xu, Alex I. Large, Georg Held, Juan-Jesus Velasco-Velez, Michael Haevecker, Axel Knop-Gericke, Chiara Genovese, Claudio Ampelli, Manfred Erwin Schuster, Siglinda Perathoner, Gabriele Centi, C. Richard A. Catlow, Rosa Arrigo
Summary: Operando soft and hard X-ray spectroscopic techniques were used to investigate Zn-containing Cu nanostructured electrocatalysts in CO2 hydrogenation reaction. The study reveals that Zn is alloyed with Cu in the bulk of the nanoparticles, while low reducible Cu(I)-O species are consumed at the interface. The Cu-Zn system represents the optimal active ensembles with stabilized Cu(I)-O, which activates CO2 and supplies H atoms for the hydrogenation reaction.
Article
Chemistry, Physical
Zijie Sha, Gwilherm Kerherve, Matthijs A. van Spronsen, George E. Wilson, John A. Kilner, Georg Held, Stephen J. Skinner
Summary: A study investigated the surface reactions and composition of a mixed ionic and electronic conducting perovskite oxide. The results showed that the surface lattice oxygen is the significant redox active species, rather than the transition metal cations. The study also observed higher concentrations of surface oxygen vacancies and the formation of hydroxyl groups in water vapor. Furthermore, the study found that the concentration of Sr surface species increased over time in dry oxygen, while less Sr contents were observed in water vapor. The findings provide crucial understanding for the design and performance of electrocatalytic electrodes.
JOURNAL OF PHYSICAL CHEMISTRY C
(2023)
Article
Chemistry, Physical
Alvaro Tolosana-Moranchel, Alvaro Garcia, Alvaro Garcia-Corral, Jose F. Marco, L. Pascual, Dalia Liuzzi, Mohamed A. Salam, Pilar Ferrer, Jorge Torrero, David C. Grinter, Georg Held, Daniel Garcia Sanchez, K. Andreas Friedrich, Maria Retuerto, Sergio Rojas
Summary: The overall performance of proton exchange membrane fuel cells is limited by the sluggish kinetics of the oxygen-reduction reaction (ORR). Among the most active PGM-free ORR electrocatalysts are metal-nitrogen-carbon (M-N-C), such as Fe-N-C. In this work, a Fe/N/C catalyst was synthesized via thermal treatment of a polymeric CxNy precursor obtained by the wet-polymerization of melamine (a nitrogen rich molecule) and terephthaldehyde, and it displayed high ORR activity in acid electrolyte compared to other Fe-N-C catalysts.
JOURNAL OF POWER SOURCES
(2023)
Article
Chemistry, Physical
Sundeep Vema, Farheen N. Sayed, Supreeth Nagendran, Burcu Karagoz, Christian Sternemann, Michael Paulus, Georg Held, Clare P. Grey
Summary: Garnet solid-electrolyte-based Li-metal batteries have the potential to be used in high-energy density and thermally stable energy storage devices. However, the formation of lithium hydroxide and carbonate on the garnet surface in an ambient atmosphere poses processing challenges. This study investigates the decomposition of surface layers under different gas environments and identifies that heating under an oxygen atmosphere leads to a clean garnet surface, while low oxygen partial pressures result in additional carbon deposits. The clean garnet surface reacts with moisture and carbon dioxide, indicating a need for control over CO2 concentration during garnet handling. Symmetric cells with low interface resistance and dendrite-free plating currents are achieved by heating under O₂ and avoiding H₂O and CO₂.
ACS ENERGY LETTERS
(2023)
Article
Chemistry, Physical
Giulio D'Acunto, Payam Shayesteh, Esko Kokkonen, Virginia Boix de la Cruz, Foqia Rehman, Zohreh Mosahebfard, Erik Lind, Joachim Schnadt, Rainer Timm
Summary: Understanding the reaction mechanisms involved in the initial stage of atomic layer deposition (ALD) of HfO2 on InAs is crucial for enhancing the interfaces in III-V semiconductor-based devices. InAs is a promising candidate to surpass silicon in terms of speed and power consumption, and when combined with HfO2, it holds the potential for a new generation of ultra-fast MOSFETs. However, a better interface quality and a thorough understanding of the surface species involved are necessary.
SURFACES AND INTERFACES
(2023)
Article
Green & Sustainable Science & Technology
Dmitry Galyamin, Jorge Torrero, Joshua David Elliott, Isabel Rodriguez-Garcia, Daniel Garcia Sanchez, Mohamed Abdel Salam, Aldo Saul Gago, Mohamed Mokhtar, Jose Luis Gomez de la Fuente, Samba Violeta Bueno, Diego Gianolio, Pilar Ferrer, David Charles Grinter, Georg Held, Maria Retuerto, Sergio Rojas
Summary: The demand for green hydrogen, produced from water electrolysis, is expected to increase significantly in the future. Current proton exchange membrane water electrolysis technology uses platinum group metals as electrode materials, but alternative low-cost materials like phosphides and sulfides are being investigated. This study presents a simple process for preparing ruthenium phosphide electrodes with high activity for the hydrogen evolution reaction, achieving comparable performance to platinum. A ruthenium phosphide catalyst-coated membrane is also tested in a proton exchange membrane water electrolysis cell, demonstrating promising current density at low catalyst loading.
ADVANCED ENERGY AND SUSTAINABILITY RESEARCH
(2023)
Article
Chemistry, Applied
Madalina Lorena Medeleanu, Anca Corina Fa, Cristina Coman, Loredana Leopold, Zorita Diaconeasa, Sonia Ancuta Socaci
Summary: Citrus essential oils are natural products with bioactive properties, and nanotechnology can overcome their limitations in the food industry.