Article
Chemistry, Physical
Alexandre S. Dumon, Amit Sahu, Pascal Raybaud
Summary: This study compares two historical mechanisms for the CAS bond scission of DBT and finds that dihydrogenation on the Co promoted M-edge is kinetically competing with hydrogenolysis, while beta-elimination on the S-edge exhibits higher activation free energies.
JOURNAL OF CATALYSIS
(2021)
Article
Energy & Fuels
Farhad Keivanimehr, Sajjad Habibzadeh, Maryam Mokhtarian
Summary: Manipulating the electronic properties of HDS catalysts by titania can enhance surface acidity and reductive behavior. CoMo/Al2O3-TiO2 with 10 wt% titania loading outperforms the catalyst without titania, removing over 96% of sulfur-containing molecules in Pygas and increasing the yield of aromatic compounds, thus improving the quality and value of the product.
Article
Chemistry, Physical
Anabel D. Delgado, Lorena Alvarez-Contreras, Karen A. Beltran, Noe Arjona, Minerva Guerra-Balcazar, Jose Bejar, Alfredo Aguilar-Elguezabal
Summary: In this study, CoMoS catalysts were synthesized and supported on porous alumina spheres for dual applications in hydrodesulfurization and energy storage. The results showed that using Pluronic P-123 as a surfactant resulted in better dispersion of MoS2 slabs on the alumina spheres, leading to improved catalytic efficiency in the hydrodesulfurization reactions. Additionally, the CoMoS catalysts exhibited excellent activity and stability for oxygen reduction and oxygen evolution reactions in rechargeable Zn-air batteries.
Article
Nanoscience & Nanotechnology
Luyao Wang, Zhe Bai, Xiangwen Zhang, Guozhu Li
Summary: Hydrodesulfurization (HDS) is an important technique utilized in the petroleum industry for environmental protection by removing harmful sulfur compounds. This study successfully anchored MoS2 nanosheets on two-dimensional Ti3C2 MXene to construct CoMoS2/Ti3C2 composite with a well-defined open structure and higher proportion of active phase. The CoMoS2/Ti3C2 catalyst exhibited significantly enhanced reaction rate constant and good stability in a harsh high-temperature reaction environment.
ACS APPLIED NANO MATERIALS
(2022)
Article
Energy & Fuels
T. S. Romanova, K. A. Nadeina, I. G. Danilova, V. V. Danilevich, V. P. Pakharukova, A. A. Gabrienko, T. S. Glazneva, E. Yu. Gerasimov, I. P. Prosvirin, Yu. V. Vatutina, M. O. Kazakov, O. V. Klimov, A. S. Noskov
Summary: The effect of Si incorporation at the stage of alumina preparation on the physico-chemical properties and catalytic performance of NiMo/Al2O3 catalysts for FCC feedstock pretreatment was studied. Silicon addition changed the texture characteristics of the support and reduced the acidity of alumina. Incorporation of Si facilitated the segregation of Ni from the NiMoS phase. Addition of Si through kneading improved the hydrodesulfurization activity of the catalysts in VGO hydrotreating.
Article
Chemistry, Multidisciplinary
Longcheng Zhang, Jie Liang, Yuanyuan Wang, Ting Mou, Yiting Lin, Luchao Yue, Tingshuai Li, Qian Liu, Yonglan Luo, Na Li, Bo Tang, Yang Liu, Shuyan Gao, Abdulmohsen Ali Alshehri, Xiaodong Guo, Dongwei Ma, Xuping Sun
Summary: MoS2/GF nanosheet on graphite felt shows promising catalytic performance in electrochemical reduction of NO for NH3 production, offering a potential environmentally friendly and efficient approach for nitrogen cycle restoration.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Applied
Youhe Wang, Long Kou, Jinzhi Lu, Dezhi Han, Zhanquan Zhang, Hongman Sun, Chang Dai, Yuxin Mao, Zifeng Yan
Summary: The layered ordered macro-mesopores (LOMM) silica-alumina composites, fabricated by an effective dual-templating approach, exhibit improved hydrodesulfurization performance in dibenzothiophene (DBT) due to their highly ordered macromesopores structure and tunable acidity. The addition of aluminum also increases the amount of acid sites, contributing to a 27% increase in desulfurization activity compared to the catalyst prepared by LOMM silica support.
MICROPOROUS AND MESOPOROUS MATERIALS
(2021)
Article
Chemistry, Physical
Koen Kennes, Alexey Kubarev, Coralie Demaret, Laureline Treps, Olivier Delpoux, Mickael Rivallan, Emmanuelle Guillon, Alain Methivier, Theodorus de Bruin, Axel Gomez, Bogdan Harbuzaru, Maarten B. J. Roeffaers, Celine Chizallet
Summary: Shaping has a significant impact on the acidity and catalytic properties of acid zeolite catalysts. The choice and use of binders can greatly affect the performance of the catalyst, with migration of cations and pore blockage being the most detrimental effects.
Article
Chemistry, Multidisciplinary
Xinlin Zhang, Yi Zheng, Jiaxing Chen, Haowen Xue, Yongjun Liu
Summary: In this work, Co-doped MoS2 catalysts were prepared through chemical exfoliation and hydrothermal methods. The effects of isolated Co doping on the catalytic performances of MoS2 were investigated using periodic density functional theory (DFT) calculations. The results showed that the prepared catalyst exhibited higher catalytic activity and could be used at lower temperatures, due to the changes in electronic structure caused by Co atom doping. This work provides a new path for improving HDS catalytic activity through synergistic structure and charge characteristics.
NEW JOURNAL OF CHEMISTRY
(2022)
Article
Energy & Fuels
Qi Zhang, Hui Shang, Zonghao Xue, Aijun Duan
Summary: The formations of sulfur vacancies over various edges of Mo-based active phases were investigated using DFT calculations. Co/Ni doping was found to reduce the difficulty, and the S-edge had lower difficulty than the M-edge. The effect of electric field direction differed for each step of vacancy formation.
Review
Chemistry, Physical
Yu Hao, Tian-Yu Sun, Liang-Feng Huang
Summary: This article reviews the role and microscopic mechanisms of defective MoS2 in electrochemical reactions from the perspective of density-functional-theory simulation. It also projects the future research trends and challenges in the electrochemical catalysis and corrosion of defective MoS2.
CURRENT OPINION IN ELECTROCHEMISTRY
(2022)
Article
Chemistry, Physical
Antara Vaidyanathan, Seetha Lakshmy, Gopal Sanyal, Saju Joseph, Nandakumar Kalarikkal, Brahmananda Chakraborty
Summary: The study used Density Functional Theory simulations to investigate the sensing properties of various materials for nitrobenzene, suggesting that Ti-doped MoS2 is a potential nanomaterial for NB sensing applications.
APPLIED SURFACE SCIENCE
(2021)
Article
Chemistry, Physical
Muhammed Acikgoz, Huixin He, Michele Pavanello
Summary: This study investigates the arrangement and local atom-level structure of P atoms on doped γ-Al2O3 surfaces and their influence on the electronic properties. The results show that the spatial arrangement and coordination of P dopant atoms significantly affect the surface's electronic properties, while the concentration of P atoms has a smaller impact.
JOURNAL OF PHYSICAL CHEMISTRY C
(2023)
Article
Engineering, Environmental
Chaohong Guan, Zhenming Xu, Hong Zhu, Xiaojun Lv, Qingsheng Liu
Summary: Activated alumina is the most common adsorbent for purifying fluoride in water, and in this study, the fluoride adsorption mechanisms on different crystal phase alumina surfaces were investigated using density functional theory. The results showed that theta-Al2O3 exhibited the highest reactivity for fluoride adsorption due to the high unsaturation level of aluminum atoms. Additionally, the bonding between fluoride and alumina surfaces was attributed to the hybridization between fluoride-p orbitals and aluminum-s,p orbitals.
JOURNAL OF HAZARDOUS MATERIALS
(2022)
Article
Chemistry, Physical
Seetha Lakshmy, Gopal Sanyal, Antara Vaidyanathan, Saju Joseph, Nandakumar Kalarikkal, Brahmananda Chakraborty
Summary: The research investigates the sensing capabilities of Ti-decorated MoS2 for catechol through DFT simulation, revealing that Ti-decorated MoS2 has higher binding energy and may be a promising nanomaterial for catechol detection.
APPLIED SURFACE SCIENCE
(2021)
Article
Chemistry, Physical
Elsy El Hayek, Sambhu Radhakrishnan, Gina Vanbutsele, Sreeprasanth Pulinthanathu Sree, Mickael Rivallan, Emmanuel Soyer, Christophe Bouchy, Eric Breynaert, Johan Martens, Celine Chizallet, Bogdan Harbuzaru
Summary: This study successfully transformed the unstable silicogermanate into a stable aluminosilicogermanate using post-synthetic isomorphic substitution. The resulting material showed promising performance in the catalytic transformation of bulky molecules, suggesting potential applications for stable derivatives of silicogermanate zeolites.
JOURNAL OF CATALYSIS
(2022)
Article
Chemistry, Physical
Thomas Pigeon, Celine Chizallet, Pascal Raybaud
Summary: This study investigates the surface properties of gamma-alumina (gamma-Al2O3) supported catalysts using density functional theory (DFT) calculations, revealing the dependence of these properties on the synthesis pathway. The topotactic transformation of boehmite (gamma-AlOOH) into gamma-Al2O3 during calcination is studied, and a methodology to simulate this pathway is proposed. The study confirms the reliability of previous surface structures and identifies new gamma-alumina surfaces with specific acid sites. The findings also highlight the differentiation of reactivity between basal and lateral alumina surfaces.
JOURNAL OF CATALYSIS
(2022)
Article
Chemistry, Physical
Koen Kennes, Alexey Kubarev, Coralie Demaret, Laureline Treps, Olivier Delpoux, Mickael Rivallan, Emmanuelle Guillon, Alain Methivier, Theodorus de Bruin, Axel Gomez, Bogdan Harbuzaru, Maarten B. J. Roeffaers, Celine Chizallet
Summary: Shaping has a significant impact on the acidity and catalytic properties of acid zeolite catalysts. The choice and use of binders can greatly affect the performance of the catalyst, with migration of cations and pore blockage being the most detrimental effects.
Article
Chemistry, Physical
Adrien Hellier, Celine Chizallet, Pascal Raybaud
Summary: In this study, the stability of platinum-based catalysts under calcination and reduction conditions was investigated using density functional theory. The results showed that the stability and nature of platinum species were highly dependent on the activation conditions, with different temperatures leading to different forms of platinum under oxygen and hydrogen environments.
Article
Chemistry, Physical
Ekaterina Galand, Fabien Caron, Etienne Girard, Antoine Daudin, Mickael Rivallan, Pascal Raybaud, Jean-Marc Schweitzer, Yves Schuurman
Summary: A Langmuir-Hinshelwood kinetic model is established to study the selective hydrodesulfurization (HDS) of fluidized catalytic cracking gasoline. The model takes into account 16 different reactions and adequately reproduces the experimental product distribution by determining rate constants and adsorption constants. The model is used to predict the impact of operating conditions on the selectivity, with an optimum desulfurization selectivity at approximately 30-50% 3MT conversion and low temperature (170 degrees C) being favorable for the HDS selectivity.
CATALYSIS SCIENCE & TECHNOLOGY
(2023)
Article
Chemistry, Multidisciplinary
Pascal Duchene, Severine Humbert, Loic Sorbier, Maxime Moreaud
Summary: The microstructure of heterogeneous catalysts, composed of multiscale aggregates of anisotropic nanoparticles, can be effectively characterized using small-angle X-ray scattering. Instead of traditional methods, this study proposes the use of multiscale Boolean models of spheroids to interpret the scattered intensities. The numerical procedure for computing the scattered intensities is validated on asymptotic diluted Boolean models and successfully applied to characterize alumina catalyst supports.
JOURNAL OF APPLIED CRYSTALLOGRAPHY
(2023)
Article
Chemistry, Physical
Thomas Pigeon, Gabriel Stoltz, Manuel Corral-Valero, Ani Anciaux-Sedrakian, Maxime Moreaud, Tony Lelievre, Pascal Raybaud
Summary: In this study, a method for computing accurate rate constants for catalytic events at surface was proposed. The method combined adaptive multilevel splitting (AMS) rare event sampling technique and ab initio molecular dynamics. Various approaches were used to build reaction coordinates, and a case study on the conformation change and dissociation of water molecule on γ-alumina (100) surface was conducted to evaluate the proposed method. The calculated rate constants and transition mechanisms were compared with the results obtained from a conventional static approach. It was found that the AMS method can provide rate constants smaller by up to 2 orders of magnitude due to entropic effects.
JOURNAL OF CHEMICAL THEORY AND COMPUTATION
(2023)
Article
Chemistry, Physical
Ana T. F. Batista, Thomas Pigeon, Jordan Meyet, Dorothea Wisser, Mickael Rivallan, David Gajan, Leonor Catita, Fabrice Diehl, Anne-Sophie Gay, Anne Lesage, Pascal Raybaud, Celine Chizallet
Summary: We use DFT calculations and proton solid-state NMR experiments to determine the exact location and spatial proximity of hydroxyl groups on gamma-alumina crystallites. We find that the hydroxyl groups are predominantly located on edges, free from the H-bond network. Chlorination selectively occurs on edges and lateral facets, resulting in the disappearance of the hydroxyl groups and disruption of the H-bond network.
Article
Engineering, Environmental
Giulia Ferri, Severine Humbert, Mathieu Digne, Maxime Moreaud, Jean-Marc Schweitzer
Summary: This study describes a method to model the three-dimensional morphology of colloidal agglomerates of boehmite under different pH conditions, and generate boehmite grains for numerical estimation of their textural properties.
CHEMICAL ENGINEERING JOURNAL ADVANCES
(2023)
Article
Chemistry, Physical
Alberto Ricchebuono, Eleonora Vottero, Andrea Piovano, Elena Groppo, Pascal Raybaud, Ceïline Chizallet
Summary: This article evaluates the performance of several low-cost methods in reproducing structural features of Pt nanoparticles of different sizes, and finds that some methods show a preference for amorphous geometries.
JOURNAL OF PHYSICAL CHEMISTRY C
(2023)
Article
Chemistry, Physical
Joudy Dankar, Celine Pagis, Mickael Rivallan, Mohamad El-Roz
Summary: The photoreduction of CO2 in the vapor phase influenced by catalytic pathways of Benchmark TiO2 and Pt/TiO2 photocatalysts was investigated through operando FTIR spectroscopy. The presence of carboxylates as carbonaceous surface impurities was identified, and their involvement in surface reactions was demonstrated.
SUSTAINABLE ENERGY & FUELS
(2023)
Article
Chemistry, Physical
Nawras Abidi, Amit Sahu, Pascal Raybaud, Stephan Steinmann
Summary: In this study, the stability and catalytic activity of carbon-supported Mo3S9-x-clusters were investigated using density functional theory. The results show that under moderate overpotentials, Mo3S9-x-clusters can undergo partial desulfurization, leading to stable working states of Mo3S8 or Mo3S7 with catalytic activity for the hydrogen evolution reaction.
Article
Chemistry, Physical
Masoud Shahrokhi, Tangui Le Bahers, Pascal Raybaud
Summary: By using density functional theory, the opto-electronic properties and high frequency dielectric constant profiles of few layer MoO3-xSx/MoS2 heterostructures have been investigated. It is found that the electronic band gap decreases and the dielectric constant increases with increasing S concentration in FL MoO3-xSx. The band gap reduction is more significant when S atoms are located in the internal bulk region, and the conduction and valence band levels shift to higher energy at the edge location.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2022)
Article
Chemistry, Multidisciplinary
Ana T. F. Batista, Celine Chizallet, Fabrice Diehl, Anne-Lise Taleb, Anne-Sophie Gay, Ovidiu Ersen, Pascal Raybaud
Summary: Quantifying the distances between metallic sites and acid sites is crucial for tuning the catalytic activity and selectivity of bifunctional catalysts. In this study, the distribution of platinum nano-particles and single atoms on an alumina support is analyzed using high resolution scanning transmission electron microscopy. A geometrical model is established to explain the variation in inter-site distances. The results show that the chlorine loading and alumina morphology have a significant impact on the inter-site distances, while the platinum loading has little effect.
Article
Chemistry, Multidisciplinary
Quentin Rivet, Jordan Meyet, Mickael Rivallan, Thibaud Nardin, David Farrusseng
Summary: The characterization of acid sites on solid catalysts is important for understanding reaction mechanisms. In this study, 2,6-di-tert-butylpyridine is found to be a suitable probe for characterizing weak Bronsted acidity. The results show that the area of a specific vibration band is correlated to the concentration of a specific element in the catalyst. The study also highlights the limitations of using pyridine as an IR probe molecule and NH3 TPD for acid site characterization.
NEW JOURNAL OF CHEMISTRY
(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)
