Article
Chemistry, Physical
Xingyue Qi, Jiaxin Fu, Kunhong Jiang, Tao Chen, Yalin He, Jiefei Li, Jing Cao, Hang Wei, Long Huang, Haibin Chu
Summary: The use of oxygen-vacancy-riched ceria supported Pd catalyst effectively alleviates the catalyst deactivation caused by the poisoning of Pd surface. It achieves high catalytic activity and stability with 100% selectivity for glucose oxidation at room temperature.
JOURNAL OF CATALYSIS
(2022)
Article
Chemistry, Physical
Ning Yuan, Arnar Gudmundsson, Karl P. J. Gustafson, Michael Oschmann, Cheuk-Wai Tai, Ingmar Persson, Xiaodong Zou, Oscar Verho, Eva G. Bajnoczi, Jan-E Backvall
Summary: By utilizing in situ X-ray absorption spectroscopy (XAS), researchers uncovered the deactivation mechanism of palladium catalyst in the cycloisomerization of acetylenic acids and developed an improved catalytic protocol that is less prone to deactivation.
Article
Chemistry, Physical
Badri P. Mainali, Dhruba K. Pattadar, Francis P. Zamborini
Summary: The oxidation resistance of gold nanoparticles has a unique reverse size dependence for thiolate-coated nanoparticles, where the extent of oxidation increases with size, opposite to weakly stabilized or bare gold nanoparticles.
JOURNAL OF PHYSICAL CHEMISTRY C
(2021)
Article
Nanoscience & Nanotechnology
Zachary Blanchette, Daniel K. Schwartz, J. Will Medlin
Summary: Controlling reactant adsorption on catalyst surfaces is crucial for reaction activity and selectivity. This study used thiol self-assembled monolayers (SAMs) to control activity and selectivity via steric effects. The successful deposition of homogeneous low-density SAMs on the metal surface was demonstrated, and the SAM density significantly influenced reaction activity and selectivity. The low-density SAMs improved reaction rates and showed potential for size-selective reaction control.
ACS APPLIED NANO MATERIALS
(2023)
Article
Chemistry, Physical
Helapiyumi Weerathunga, Cheng Tang, Aidan J. Brock, Sarina Sarina, Tony Wang, Qiong Liu, Huai-Yong Zhu, Aijun Du, Eric R. Waclawik
Summary: Selective oxidation of alcohols is crucial for fine chemical production, and the photocatalytic oxidation of benzyl alcohol using ZnO nanocrystals was investigated in this study. Different shapes of ZnO nanocrystals displayed varying kinetics for the benzyl alcohol oxidation reaction, with nanocones showing the highest conversion rate. The {10 (1) over bar1} facet of ZnO was found to expose undercoordinated O atoms, leading to the highest adsorption of benzyl alcohol and ultimately resulting in 100% selectivity for benzaldehyde as the product.
JOURNAL OF COLLOID AND INTERFACE SCIENCE
(2022)
Article
Engineering, Environmental
Jing Luo, Chenghao Zhang, Wei Liu, Bingqi Xie, Jisong Zhang
Summary: This study achieved covalent grafting of TEMPO on activated carbon through surface-formylation and reductive amination, opening up a new avenue for surface modification and preparing heterogeneous catalysts based on carbon materials. The catalysts were used in a micro-packed bed reactor for continuous oxidation of various alcohols, and the catalytic performance in the conversion of benzyl alcohol to benzaldehyde (turnover number: 1160.6, turnover frequency: 99.6 h-1) was significantly better than previous reports using covalently grafted heterogeneous TEMPO catalysts.
CHEMICAL ENGINEERING JOURNAL
(2023)
Article
Chemistry, Physical
Dimitrios Stefanakis, Vangelis Harmandaris, Georgios Kopidakis, Ioannis Remediakis
Summary: The study examines the impact of substrate on the structural properties and morphology of alkanethiol self-assembled monolayers on gold surfaces through calculations and simulations. Changes in substrate lead to transitions from order to disorder, with substrate morphology playing a crucial role in determining long-range order.
JOURNAL OF PHYSICAL CHEMISTRY C
(2021)
Article
Chemistry, Physical
Amanda Filie, Tanya Shirman, Alexandre C. Foucher, Eric A. Stach, Michael Aizenberg, Joanna Aizenberg, Cynthia M. Friend, Robert J. Madix
Summary: Dilute alloy catalysts, particularly Pd-in-Au nanoparticle alloys, demonstrate enhanced selectivity and activity in oxidative coupling of methanol reactions. Low concentrations of palladium in bimetallic nanoparticles are effective in catalyzing the production of methyl formate with high selectivity of up to 95% under certain reaction conditions.
JOURNAL OF CATALYSIS
(2021)
Article
Chemistry, Physical
Mickael Henrion, Yorck Mohr, Kwinten Janssens, Simon Smolders, Aram L. Bugaev, Oleg A. Usoltsev, Elsje Alessandra Quadrelli, Florian M. Wisser, Dirk E. De Vos, Jerome Canivet
Summary: New catechol-based porous polymers were synthesized and used as platforms for the heterogenization of molecular Cu complexes. The resulting Cu@CatMP-1 materials proved to be highly stable and performing catalysts with turnover numbers up to 6000, about 1 to 2 orders of magnitude higher than the current relevant state of the art. The solid catalyst showed recyclability for over 10 runs without metal leaching and has been scaled to the gram scale. The coordination of Cu to catechol within the polymer has been confirmed by X-ray absorption spectroscopy.
Article
Chemistry, Inorganic & Nuclear
Samir Chattopadhyay, Sabyasachi Bandyopadhyay, Abhishek Dey
Summary: The study investigates the long-range electron transfer (ET) process across several SAM-covered Au electrodes to covalently attached ferrocene, showing a significant kinetic isotope effect (KIE) that shifts substantially upon deuteration of thiols.
INORGANIC CHEMISTRY
(2021)
Article
Chemistry, Physical
Umit Celik, Han Ju Lee, Terell Keel, Logan A. Swartz, Marshall Van Zijll, Cody J. Chalker, T. Randall Lee, Gang-yu Liu
Summary: This study provides molecular-level structural information on dithiol SAMs by investigating OPDT SAMs on Au(111) surfaces, revealing a lack of long-range order in high coverage OPDT SAMs. The study shows that within ordered domains, OPDT molecules can be lying-down or standing-up, randomly distributed on Au(111) with little long-range order.
JOURNAL OF PHYSICAL CHEMISTRY C
(2021)
Review
Electrochemistry
Anna Tverdokhlebova, Ilya Sterin, Oleh Smutok, Evgeny Katz
Summary: The paper provides a detailed overview of the scientific background from the 1970s to the 1990s, which led to significant advancements in the preparation of modified electrodes for various applications. The focus of the paper is on the chemisorption of sulfur-containing molecules on metal electrodes, resulting in well-structured monolayers with unique chemical and electrochemical features. Unlike other reviews, this paper does not emphasize the recent achievements in the field, but instead provides a thorough analysis of the research background from 30 to 50 years ago, primarily aimed at educational purposes.
JOURNAL OF SOLID STATE ELECTROCHEMISTRY
(2023)
Article
Chemistry, Applied
Jennifer N. Jocz, Phillip E. Savage, Levi T. Thompson
Summary: The study identified a library of catalytic materials that are thermodynamically stable under hydrodenitrogenation conditions, selecting a Pt/TiO2 catalyst for experiments. Results showed that the Pt/TiO2 catalyst exhibited high activity for propylamine in supercritical water, experiencing minimal dissolution at 500 degrees C.
Article
Multidisciplinary Sciences
Yanyan Zhao, Sheng Dai, Ke R. Yang, Sufeng Cao, Kelly L. Materna, Hannah M. C. Lant, Li Cheng Kao, Xuefei Feng, Jinghua Guo, Gary W. Brudvig, Maria Flytzani-Stephanopoulos, Victor S. Batista, Xiaoqing Pan, Dunwei Wang
Summary: Atomically dispersed catalysts have shown high activity for selective oxidation of carbon monoxide with excess hydrogen, but their stability is not ideal. This study demonstrates that introducing a structural component to minimize the diffusion of the active metal center significantly improves stability without compromising activity. By using a dinuclear iridium heterogeneous catalyst as a study platform, two types of oxygen species, interfacial and bridge, are identified to work together for both activity and stability. This work provides important insights into the synergistic effect between the active metal center and the supporting substrate, with potential broad applications for atomically dispersed catalysts.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2023)
Article
Chemistry, Physical
Caitlin Kozack, Stephen J. Tereniak, Jonathan N. Jaworski, Bao Li, David L. Bruns, Spring M. M. Knapp, Clark R. Landis, Shannon S. Stahl
Summary: This study focuses on the impact of benzoquinone on the catalytic activity in palladium(II)-catalyzed allylic acetoxylation. The results indicate that benzoquinone enhances the performance of the catalyst, showing a synergistic effect with Co(salophen) in improving reaction performance. The mechanistic studies suggest that both benzoquinone and oxygen play significant roles in oxidizing Pd(0) to Pd(II), leading to better reaction outcomes.
Article
Chemistry, Physical
Zachary Blanchette, Jing Zhang, Sadegh Yazdi, Michael B. Griffin, Daniel K. Schwartz, J. Will Medlin
Summary: Modification of supported metal catalysts with self-assembled monolayers (SAMs) can improve site accessibility and reactivity. SAM-first catalysts show higher rates and similar TOF and selectivity compared to metal-first catalysts. Reduced site blocking and smaller particle sizes contribute to the improved activity of SAM-first catalysts.
CATALYSIS SCIENCE & TECHNOLOGY
(2022)
Article
Chemistry, Physical
Laura Paz Herrera, Lucas Freitas de Lima e Freitas, Jiyun Hong, Adam S. Hoffman, Simon R. Bare, Eranda Nikolla, J. Will Medlin
Summary: In this study, the synergistic interactions in encapsulated catalytic structures between the metal core and oxide shell were investigated. The encapsulated catalytic systems displayed higher activity than the supported structures, and the composition and crystallinity of the oxide shell played major roles in catalyst activity.
CATALYSIS SCIENCE & TECHNOLOGY
(2022)
Article
Chemistry, Physical
Benjamin Greydanus, Mohammad Saleheen, Haichao Wu, Andreas Heyden, J. Will Medlin, Daniel K. Schwartz
Summary: This study utilizes the motion of self-propelled catalytic Janus particles to measure the effective surface coverage of adsorbate molecules on a platinum surface. The research shows significant differences in surface affinity among different adsorbates, with each reaching saturation at a specific coverage level. Experimental and computational investigations reveal the correlation between surface coverage at saturation and adsorption energy, providing a novel approach for multidisciplinary research.
JOURNAL OF COLLOID AND INTERFACE SCIENCE
(2022)
Article
Chemistry, Applied
Xinpei Zhou, John L. Falconer, J. Will Medlin
Summary: This study reports that the ideal selectivity of C3H6/C3H8 adsorption can be significantly enhanced by changing the diffusion mechanism. Organic phosphonic acid monolayers can limit the diffusion of C3H6 and C3H8, leading to increased adsorption selectivity. The use of organic films may enable the rational design of selective adsorbents.
MICROPOROUS AND MESOPOROUS MATERIALS
(2022)
Article
Chemistry, Physical
Benjamin Greydanus, J. Will Medlin, Daniel K. Schwartz
Summary: The adsorption strengths of organic compounds on metal surfaces are crucial for catalytic reactions, but they can be altered by the presence of solvent in liquid-phase reactions. This study investigates the effect of metal composition on binding strengths in a liquid environment by using the motion of active particles in water to probe the adsorption energies of an organic adsorbate on a range of metal surfaces.
JOURNAL OF PHYSICAL CHEMISTRY C
(2023)
Article
Nanoscience & Nanotechnology
Nathanael C. Ramos, J. Will Medlin, Adam Holewinski
Summary: The stable electrochemical potential window of thiolate self-assembled monolayers (SAMs) on Au, Pt, and Cu electrodes is studied systematically in aqueous electrolyte systems. The reductive stability is found to depend on the binding strength of sulfur and competitive adsorption of hydrogen, while the oxidative stability is related to each surface's propensity toward surface oxide formation. The stability of SAMs is also influenced by factors such as SAM defects, intermolecular interactions, SAM thickness, and the ability to directly oxidize or reduce the non-sulfur part of the SAM molecule.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Nanoscience & Nanotechnology
Zachary Blanchette, Daniel K. Schwartz, J. Will Medlin
Summary: Controlling reactant adsorption on catalyst surfaces is crucial for reaction activity and selectivity. This study used thiol self-assembled monolayers (SAMs) to control activity and selectivity via steric effects. The successful deposition of homogeneous low-density SAMs on the metal surface was demonstrated, and the SAM density significantly influenced reaction activity and selectivity. The low-density SAMs improved reaction rates and showed potential for size-selective reaction control.
ACS APPLIED NANO MATERIALS
(2023)
Article
Biochemistry & Molecular Biology
Evan A. Bisirri, Thaiesha A. Wright, Daniel K. Schwartz, Joel L. Kaar
Summary: Protein-polymer conjugation is a useful approach to improve protein stability and performance, but polymer-polymer interactions can also affect the properties of polymer-modified proteins. This study demonstrates that by adjusting the ratio of polymers, the productivity of lipase can be optimized, although this may lead to a trade-off between activity and stability.
Article
Electrochemistry
Francisco W. S. Lucas, Nathanael C. Ramos, Daniel K. Schwartz, J. Will Medlin, Adam Holewinski
Summary: Thiolate self-assembled monolayers (SAMs) are commonly used to modify surface properties, including catalytic activity. It is shown that irreversible changes to the metal surface, caused by the formation and removal of thiolate SAMs, can lead to significant changes in catalytic properties, regardless of specific interactions with reactants.
ELECTROCHIMICA ACTA
(2023)
Article
Chemistry, Physical
Alexander H. Jenkins, Erin E. Dunphy, Michael F. Toney, Charles B. Musgrave, J. Will Medlin
Summary: This study investigates the effects of modifying single-atom Rh-1/TiO2 catalysts with functionalized phosphonic acid monolayers on CO2 hydrogenation. The deposition of specific amine-functionalized ligands significantly enhances the catalytic activity and stability of the catalysts. The proximity of the amine functional group to the surface, controlled by adjusting the length of the phosphonic acid tail, plays a crucial role in the reactivity. The modification also improves the selectivity of the catalyst towards CO.
Article
Chemistry, Multidisciplinary
Jacob K. Kenny, David G. Brandner, Sasha R. Neefe, William E. Michener, Yuriy Roman-Leshkov, Gregg T. Beckham, J. Will Medlin
Summary: Hydrogen-free reductive catalytic fractionation (RCF) is a promising method to extract and depolymerize lignin from native biomass. Pt/C and Pd/C achieve comparable monomer yields regardless of hydrogen pressure, while Ru/C and Ni/C show lower yields under H-2-free conditions. Pt/C and Pd/C can form ethyl and propanol products through dehydrogenation and hydrogenation reactions. Adding water increases the selectivity of propyl products. Similar trends in yield and selectivity are observed for poplar RCF and reactions with coniferyl alcohol, indicating the importance of stabilization rate of reactive monomer intermediates in H-2-free RCF.
REACTION CHEMISTRY & ENGINEERING
(2022)
Article
Physics, Multidisciplinary
Ohad Vilk, Erez Aghion, Tal Avgar, Carsten Beta, Oliver Nagel, Adal Sabri, Raphael Sarfati, Daniel K. Schwartz, Matthias Weiss, Diego Krapf, Ran Nathan, Ralf Metzler, Michael Assaf
Summary: Anomalous diffusion or transport, characterized by the nonlinear relationship between mean-squared displacement and measurement time, is widely observed in nature. Using data from various empirical systems, a method is employed to detect the individual origins of anomalous diffusion and transport. The method identifies three primary effects: long-range correlations, fat-tailed probability density of increments, and nonstationarity. The decomposition of real-life data allows for nontrivial behavioral predictions and resolves open questions in single-particle tracking and movement ecology.
PHYSICAL REVIEW RESEARCH
(2022)
Article
Chemistry, Physical
Yifan Sun, Ye Lv, Wei Li, Jinli Zhang, Yan Fu
Summary: In this study, PtRu electrocatalysts were fabricated on carbon paper via cyclic electrodeposition for the electrocatalytic hydrogenation (ECH) of phenol. The Pt3Ru3 catalyst exhibited excellent activity and stability for the conversion of phenol to cyclohexanol at ambient temperature and various current densities. The in situ Raman spectroscopy and kinetic study revealed the hydrogenation mechanism of phenol over Pt3Ru3 in acidic electrolyte, providing an effective electrochemical strategy for the facile construction of durable electrode materials and efficient phenol hydrogenation.
JOURNAL OF CATALYSIS
(2024)
Article
Chemistry, Physical
Amir Shahzad, Khezina Rafiq, Muhammad Zeeshan Abid, Naseem Ahmad Khan, Syed Shoaib Ahmad Shah, Raed H. Althomali, Abdul Rauf, Ejaz Hussain
Summary: Photocatalytic hydrogen production through water splitting is an effective method for meeting future energy demands. In this study, researchers synthesized a 1 % Ag2S/Cu2S co-doped CdZnS catalyst and found that it can produce hydrogen at a higher rate. The co-doping of Ag2S and Cu2S in the CdZnS catalyst showed a synergistic effect, with Ag2S promoting oxidation reactions and Cu2S promoting reduction reactions.
JOURNAL OF CATALYSIS
(2024)
