Article
Chemistry, Physical
Han Guo, Patricia Poths, Philippe Sautet, Anastassia N. Alexandrova
Summary: This study delves into the dynamic process of copper oxide nanoclusters in catalytic applications, revealing that oxygen integration into the clusters is not a simple process and involves multiple steps. The diverse reaction profiles observed highlight the importance of dynamic effects in the mechanisms, kinetic models, and catalyst design principles.
Article
Multidisciplinary Sciences
Yifan Wang, Jake Kalscheur, Ya-Qiong Su, Emiel J. M. Hensen, Dionisios G. Vlachos
Summary: Understanding the evolution of the catalyst's structure under working conditions is challenging. The study introduces a multiscale modeling framework and machine learning to investigate the structures and nucleation of CeO2-supported Pd clusters and single atoms at different catalyst loadings, temperatures, and exposures to CO. Experimental data lacks simultaneous temporal and spatial resolution, hindering accurate structure determination.
NATURE COMMUNICATIONS
(2021)
Article
Chemistry, Physical
Yifan Wang, Ya-Qiong Su, Emiel J. M. Hensen, Dionisios G. Vlachos
Summary: Subnanometer catalysts provide high noble metal utilization and superior performance for various reactions. However, understanding their atomic-scale structures and properties under working conditions is challenging due to the large configurational space. In this study, an efficient multiscale framework integrating density functional theory (DFT) calculations, cluster expansion, machine learning, and structure optimization is introduced to predict the stability of catalysts exposed to adsorbates. The framework enables automatic discovery of stable catalyst structures and a systematic strategy to exploit properties at the subnanometer scale. Simulation results for CO-adsorbed Pd-n (n = 1-55) clusters on CeO2(111) reveal that CO can facilitate restructuring by stabilizing smaller planar structures and bilayer structures of specific intermediate sizes.
CHEMISTRY OF MATERIALS
(2022)
Article
Chemistry, Multidisciplinary
Qi Xu, Chenxi Guo, Beibei Li, Zedong Zhang, Yajun Qiu, Shubo Tian, Lirong Zheng, Lin Gu, Wensheng Yan, Dingsheng Wang, Jian Zhang
Summary: In this study, a doping strategy using Al3+ was successfully employed to construct single-atom Cu on MgO nanosheets (Cu-1/MgO(Al)) for promoting the free-radical hydrophosphinylation of alkenes. The Cu-1/MgO(Al) catalyst exhibited superior activity, durability, and anti-Markovnikov selectivity compared to Cu/MgO catalyst without Al3+ doping.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)
Review
Chemistry, Physical
Ali M. Abdel-Mageed, Shilong Chen, Corinna Fauth, Thomas Haering, Joachim Bansmann
Summary: The study investigates the fundamental characteristics and complex structure-reactivity relationship of highly active Au/CeO2 catalysts in CO oxidation using various techniques, including operando X-ray absorption spectroscopy, in situ diffuse reflectance FTIR, and Raman spectroscopy. The results highlight the complex relationship among the oxidation state, size of the Au nanoparticles, the redox properties of CeO2 support, and the dynamics of O-2 activation.
Article
Multidisciplinary Sciences
Fumiaki Sato, Ryoya Shiomoto, Shigeki Nakauchi, Tetsuto Minami
Summary: The relationship between posture and perception has been investigated, and this study found that neck posture affects the perception of the Necker cube. The results suggest that the probability of perception is modulated by posture.
SCIENTIFIC REPORTS
(2022)
Review
Nanoscience & Nanotechnology
Yang Liu, Avik Halder, Soenke Seifert, Nicholas Marcella, Stefan Vajda, Anatoly Frenkel
Summary: Size-selected clusters are significant model catalysts due to their narrow size and compositional distributions, but the structure-activity relationships are generally challenging to determine because of the difficulty in identifying and quantitatively characterizing the catalytic active site in the clusters.
ACS APPLIED MATERIALS & INTERFACES
(2021)
Article
Chemistry, Physical
Li Li, Jason A. Chalmers, Simon R. Bare, Susannah L. Scott, Fernando D. Vila
Summary: In this study, the experimental characteristics of Ga(I) oxidation state were investigated by recording Ga K-edge X-ray absorption spectra for several well-defined molecular and crystalline Ga(I) compounds. Compared to trigonal Ga(III)-containing materials, Ga(I) spectra displayed a significantly more intense white line feature. Theoretical simulations confirmed this observation and revealed that the strong XANES intensity originated from transitions to several empty, nearly degenerate p-like states.
Article
Materials Science, Multidisciplinary
Andres Alvarez-Garcia, Jonathan Casildo Luque-Ceballos, Lauro Oliver Paz-Borbon, Ignacio L. Garzon
Summary: This theoretical study investigates the structural, energetic, electronic, and vibrational properties of sub-nanometer clusters of Pt-Re on the MgO(100) surface. Results show that the MgO(100) surface has a significant effect on the properties of the Pt-Re bimetallic clusters, leading to changes in metal-metal bond lengths and vibrational frequencies. The metal-support interaction also results in charge transfer and hybridization between the metal oxide and metal clusters. These findings contribute to the understanding of the role of support in bimetallic clusters on metal oxides and their potential applications in nanocatalysis.
COMPUTATIONAL MATERIALS SCIENCE
(2022)
Article
Chemistry, Physical
Kousik Das, Ratnadip De, Francis Verpoort, Soumyajit Roy
Summary: This study demonstrates the compartmentalization and micro-heterogeneity induction in a continuous reaction medium of water and CO2 using a SOM catalyst, with successful reduction of CO2 to formic acid. The compartmentalized reaction spaces show different catalytic principles, with perturbation of catalyst surface area inversely affecting product yield. The assembly-disassembly cascade illustrates the application of systems chemistry principles in controlled catalysis and release of products.
JOURNAL OF MATERIALS CHEMISTRY A
(2021)
Article
Chemistry, Physical
Yubing Lu, Coogan Thompson, Chun-Te Kuo, Xiwen Zhang, Adam S. Hoffman, Alexey Boubnov, Simon R. Bare, Libor Kovarik, Hongliang Xin, Ayman M. Karim
Summary: The oxidation of CO on Pt group metals is influenced by the size of the metal and the reducibility of the oxide support. This study reveals that Ir supported on MgAl2O4, which is traditionally considered non-reducible, exhibits properties similar to reducible oxides when the Ir size is in the subnanometer range.
JOURNAL OF MATERIALS CHEMISTRY A
(2022)
Article
Physics, Applied
Alexander Large, Jake Seymour, Wilson Quevedo Garzon, Kanak Roy, Federica Venturini, David C. Grinter, Luca Artiglia, Emily Brooke, Martha Briceno de Gutierrez, Agnes Raj, Kevin R. J. Lovelock, Roger A. Bennett, Tugce Eralp-Erden, Georg Held
Summary: Near ambient pressure x-ray photoelectron spectroscopy (NAP-XPS) was used to study the chemical states of alumina-supported monometallic Pd and bimetallic Pd-Pt nanocatalysts under methane oxidation conditions. The presence of Pt was found to be linked to Pd oxidation and catalyst activity under stoichiometric reaction conditions, while under oxygen-rich conditions, the behavior was less clear. However, adding Pt in place of Pd still showed benefits for complete oxidation of methane.
JOURNAL OF PHYSICS D-APPLIED PHYSICS
(2021)
Article
Chemistry, Physical
J. Fabila, D. Romero, O. Paz-Borbon, F. Buendia
Summary: A comprehensive computational study on the oxygen adsorption and activation on bimetallic Au-Ir subnanometer clusters supported on TiO2(101) is performed. The results indicate a strong cluster-oxide interaction for Ir clusters and Au-Ir clusters, while a weaker interaction is observed for Au clusters. The geometric arrangements of the clusters play an important role in oxygen adsorption and dissociation.
JOURNAL OF CHEMICAL PHYSICS
(2022)
Editorial Material
Chemistry, Physical
Lichen Liu, Avelino Corma
Summary: Identifying active sites in supported catalysts with isolated metal atoms and subnanometric clusters is challenging due to the difficulty in obtaining detailed structural information under reaction conditions. Limitations and pitfalls may be encountered, but suggestions can help overcome them.
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)
Editorial Material
Chemistry, Physical
Damien Alloyeau, Vincenzo Amendola, Catherine Amiens, Pascal Andreazza, Joost M. Bakker, Francesca Baletto, Stephan Barcikowski, Noelia Barrabes, Michael Bowker, Fuyi Chen, Emmanuel Cottancin, Wolfgang E. Ernst, Riccardo Ferrando, Georg Daniel Forster, Alessandro Fortunelli, Didier Grandjean, Hazar Guesmi, Graham J. Hutchings, Ewald Janssens, Miguel Jose Yacaman, Christian Kuttner, Lebohang Macheli, Eric Marceau, Marcelo M. Mariscal, Jette K. Mathiesen, John McGrady, Christine Mottet, Diana Nelli, Pinkie Ntola, Cameron J. Owen, Micha Polak, Jonathan Quinson, Cesare Roncaglia, Leonid Rubinovich, Rolf Schafer, Manoj Settem, Jeff Shield, Mzamo Shozi, Swathi Swaminathan, Stefan Vajda, Hans-Christian Weissker
FARADAY DISCUSSIONS
(2023)
Article
Chemistry, Physical
Juraj Jasik, Stanislav Valtera, Mykhailo Vaidulych, Muntaseer Bunian, Yu Lei, Avik Halder, Hana Tarabkova, Martin Jindra, Ladislav Kavan, Otakar Frank, Stephan Bartling, Stefan Vajda
Summary: The effects of composition and support on the catalytic activity and selectivity in the oxidative dehydrogenation of cyclohexene were investigated. The study found that ultra-nanocrystalline diamond supported clusters were highly active and mainly produced benzene, while some mixed clusters produced cyclohexadiene. TiO2-supported tetramers solely produced benzene without any combustion to CO2. The selectivity of zirconia-supported mixed CuPd clusters and monometallic Cu cluster differed significantly, with the former producing significant fractions of cyclohexadiene.
FARADAY DISCUSSIONS
(2023)
Article
Chemistry, Multidisciplinary
Dongfang Cheng, Ziyang Wei, Zisheng Zhang, Peter Broekmann, Anastassia N. Alexandrova, Philippe Sautet
Summary: The dynamic restructuring of Cu surfaces in electroreduction conditions was investigated using first-principles calculations and operando electrochemical scanning tunneling microscopy experiments. The restructuring of Cu(111) in acidic electrolyte was found to be potential- and pH-dependent. The strong adsorption of H atoms on the surface induced the formation of Cu adatoms, creating highly active sites for the hydrogen evolution reaction.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Physical
Patricia Poths, Borna Zandkarimi, Anastassia N. Alexandrova, Elisa Jimenez-Izal
Summary: This study explores the effect of Ge content on PtGe cluster alloys for ethane dehydrogenation. It is found that the addition of Ge improves the stability and selectivity of the catalyst, with the optimal Ge to Pt ratio being 1:4. The concentration of Ge plays an important role in the stability and selectivity of Pt clusters.
Article
Chemistry, Physical
Nina M. M. Sackers, Julia Nikodemus, Regina Palkovits, Philippe Sautet, Peter J. C. Hausoul
Summary: Despite previous kinetic studies, the mechanism of polyol hydrogenolysis on a Ru catalyst surface remains unclear. To gain insight into the mechanism, decomposition of methanol was investigated using a Ru/C catalyst and periodic DFT calculations on a Ru(0001) model surface. The results suggest that the surface is likely covered by hydrogen adsorbates during the experiments. On a clean Ru surface, a lower overall activation barrier is observed when fewer dehydrogenation steps occur before C-O bond cleavage in the substrate methanol. Transferring these findings to a hydrogen-saturated Ru surface, the pathway involving CH2O O-H formation and subsequent C-O cleavage is found to be the most favorable. This study highlights the significant influence of surface coverage on the activation barrier.
Article
Chemistry, Physical
Robert H. Lavroll, Jason Wang, Michael G. White, Philippe Sautet, Anastassia N. Alexandrova
Summary: The formation of substoichiometric titanium oxide dendritic structures on Au(111) terraces is studied computationally and found to follow the classical fractal formation mechanism of diffusion-limited aggregation (DLA). Gas-phase oxide cluster structures, optimized globally, are sampled in various landing formations on gold surfaces, and shown to favor isomers that drive polymerization to form Brownian tree fractal structures. The mobility of Ti3O5 monomers is found to be extremely high, with diffusion barriers of 0.21 eV or less. Polymerization of these monomers is energetically favorable and irreversible on the 111 terrace due to bonding stabilization, but geometrically impossible to propagate along the step edge. Simulated scanning tunneling microscopy (STM) images show a strong resemblance to experimental observations. On the other hand, the aggregation of Ti3O6 as wires along step edges is explained by the affinity of oxygen to step edges, statistical arguments for aggregation entropy at the step, as well as low barriers for monomer diffusion and polymerization.
JOURNAL OF PHYSICAL CHEMISTRY C
(2023)
Article
Chemistry, Physical
Celine Tesvara, Christopher J. Karwacki, Philippe Sautet
Summary: Understanding the decomposition chemistry of chemical warfare agents (CWAs) is crucial for designing effective personal protective equipment against chemical attacks. This study explores the decomposition pathways of sarin on a TiO2(110) surface, both with and without surface oxygen vacancies. The presence of oxygen vacancies significantly reduces the barriers to cleave the P-F and P-OR bonds, allowing for decomposition at a lower temperature. The decomposition of sarin proceeds faster on the oxygen vacancy compared to its simulant DMMP.
JOURNAL OF PHYSICAL CHEMISTRY C
(2023)
Article
Chemistry, Physical
Simran Kumari, Philippe Sautet
Summary: In this study, the active site of a single Pt atom supported on indium tin oxide for the oxygen evolution reaction (OER) was theoretically investigated using density functional theory calculations and grand canonical basin hopping. It was found that the ligands on the Pt atom change from Pt-OH to PtO(OH)4 under electrochemical conditions, resulting in a decrease of 0.3 V for the OER overpotential. This highlights the importance of accurately identifying the nature of the active site under reaction conditions and the impact of adsorbates on the electrocatalytic activity. This theoretical investigation enhances our understanding of SACs for the OER.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2023)
Article
Chemistry, Multidisciplinary
Mustafa Karatok, Hio Tong Ngan, Xiwen Jia, Christopher R. O'Connor, J. Anibal Boscoboinik, Dario J. Stacchiola, Philippe Sautet, Robert J. Madix
Summary: Palladium-silver-based alloy catalysts have the potential for CO-free hydrogen production from formic acid. The selective decomposition of formic acid on Pd-Ag alloys was investigated, and it was found that surface Ag domains modified by interaction with subsurface Pd are the key active sites for selective decomposition. In contrast, surface Pd atoms are detrimental to selectivity. The decomposition pathways can be tailored for CO-free H2 production on Pd-Ag alloy systems.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Chemistry, Multidisciplinary
Simran Kumari, Tsugunosuke Masubuchi, Henry S. White, Anastassia Alexandrova, Scott L. Anderson, Philippe Sautet
Summary: A combination of DFT and experiments was used to study the electrocatalytic activity of Ptn clusters on ITO electrodes. The activity was found to increase with increasing Ptn size and was negligible for isolated Pt atoms on ITO. The adsorption of H atoms on Ptn/ITO was found to be about double the Hupd observed for Pt bulk or nanoparticles. The study also revealed the importance of considering multiple metastable structures and their reactions to accurately predict the activity.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Chemistry, Multidisciplinary
Kangze Shen, Simran Kumari, Yu-Chao Huang, Joonbaek Jang, Philippe Sautet, Carlos G. Morales-Guio
Summary: Electrochemical partial oxidation of methane to methanol using transition metal (oxy)hydroxides as catalysts is investigated. CoOx, NiOx, MnOx, and CuOx are found to be active for this reaction. Systematic studies are carried out to evaluate the effect of catalyst film thickness, overpotential, temperature, and hydrodynamics on activity and methanol selectivity. It is shown that high-valence transition metal oxides are inherently active for methane activation and oxidation to methanol, and electrocatalytic oxidation enables thermodynamically favorable production of methanol.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Chemistry, Physical
Dipna A. Patel, Georgios Giannakakis, George Yan, Hio Tong Ngan, Peng Yu, Ryan T. Hannagan, Paul L. Kress, Junjun Shan, Prashant Deshlahra, Philippe Sautet, E. Charles H. Sykes
Summary: The stability issues associated with Cu nanoparticle sintering can be addressed by the addition of small amounts of Ni, which further boost reactivity while retaining selectivity, thus achieving the goal of nonoxidative ethanol dehydrogenation to produce acetaldehyde.
Article
Chemistry, Physical
Zahra Almisbaa, Hassan A. Aljama, Khalid Almajnouni, Luigi Cavallo, Philippe Sautet
Summary: DFT-based reaction profiles and microkinetic simulations were used to investigate the selective hydrogenation of acetylene on Ni-based intermetallic catalysts. Among the tested catalysts, NiIn showed the highest ethylene yield, while NiIn and Ni2In3 exhibited reduced ethane formation and increased oligomerization compared to Ni and Ni3In. The findings emphasize the importance of considering oligomerization reactions and coverage effects when evaluating the selectivity of catalysts. Additionally, the presence of indium on the catalytic surface was found to decrease the rate of acetylene consumption, highlighting a trade-off between activity and selectivity.
Article
Chemistry, Physical
Ziyang Wei, George Yan, Philippe Sautet
Summary: In this study, the surface properties of ceria-based catalyst were investigated. It was found that hybrid functionals and DFT + U approach showed opposite trends for different surface properties. The results suggested that the parameter-free many-body perturbation theory methods, exemplified by RPA, have high accuracy and potential in describing catalytic reactions in ceria-related systems.
JOURNAL OF CHEMICAL PHYSICS
(2023)
Article
Chemistry, Multidisciplinary
Tomas Strysovsky, Martina Kajabova, Robert Prucek, Ales Panacek, Karolina Simkovicova, Stefan Vajda, Zdenek Bastl, Libor Kvitek
Summary: Converting CO2 to value-added products is significant, and this study demonstrates the temperature-dependent selectivity of copper-decorated indium oxide catalysts.
JOURNAL OF CO2 UTILIZATION
(2023)
