Sonochemical Defect Engineering for Sustainable CO2 Methanation over Ni/CeO2 Catalysts with Mechanistic Insights from Operando Studies Marcela A. Lucas, Paulo N. Lisboa‐Filho, Luiz G. Possato Chemistryselect, 2025 The conversion of CO2 into synthetic fuels represents a sustainable strategy to mitigate climate change and close the carbon cycle. In this work, we report the sonochemically‐assisted synthesis of Ni/CeO2 catalysts via co‐precipitation, enabling precise control of Ni dispersion, Ce3+/Ce4+ redox dynamics, and oxygen vacancy density, which are key parameters for efficient CO2 methanation. The NiCe0 sample, prepared without ultrasound, achieved 15% CO2 conversion, whereas the NiCe9 sample, subjected to 90 min of sonochemical treatment, showed significantly higher CO2 conversion. By systematically tuning ultrasound exposure time, we achieved defect engineering at the CeO2 surface, which was directly correlated with catalytic performance and selectivity. Operando Raman spectroscopy provided real‐time mechanistic insights, revealing that samples with higher vacancy densities favored the formate‐mediated pathway toward CH4 formation, while lower‐defect samples led to increased CO production. These spectroscopic findings were further supported by XPS and H2‐TPR analyses. Our results establish a clear link between synthesis parameters, structural defects, and catalytic pathways, offering a sustainable and mechanistically guided route for designing efficient CO2 methanation catalysts.
Refinement of Crystal Structure and its Application for Catalytic Materials Gabriel Ribeiro da Silva, Gabriel Alves da Silva, João Pedro Dias Querino, Luiz Gustavo Possato European Journal of Inorganic Chemistry, 2025 Rietveld refinement provides comprehensive insights into the atomic‐scale structure of catalytic materials, and thus, the methodology has emerged as a very important tool in catalytic materials studies. With an emphasis on the Rietveld approach and its crucial role in characterizing complex systems, this overview traces the development of crystallographic techniques. The ability of the technique to adjust atomic positions, lattice parameters, and occupancy factors allows for a more complete understanding of the structure–activity relationships of catalysts and a more rational design for improved performance. Key applications discussed include identifying active sites in metal catalysts, the analysis of phase transitions in metal oxides, and quantifying defects and oxygen vacancies in mixed metal oxides and metal‐organic frameworks. In addition, complementary techniques such as spectroscopy and computational modeling can be a very positive strategy for elucidating reaction mechanisms. Practical applications strengthen the research influence to improve the performance of catalysts applied for CO2 reduction, hydrogen generation, and hydrocarbon conversion processes.
Fundamentals and development of oxidation catalysts: the acrylic acid manufacture case Luiz H. Vieira, Leandro Martins, Luiz G. Possato Catalysis Reviews Science and Engineering, 2025 The oxidation catalysts are essential since the oxidation processes yield 25% of the foremost organic compounds and industrial intermediates. The review considers the fundamental concepts of catalytic oxidation, highlighting acrolein oxidation, the main product of which is acrylic acid. Besides presenting the evolution of catalysts based on mixed oxides of molybdenum and vanadium (Mo-V-O) during almost 70 years of study, it discusses how introducing other elements is essential to increase the catalytic activity and how the synthesis and reaction conditions affect the acrolein conversion and acrylic acid selectivity. The second part of the review presents new trends in acrylic acid formation, where acrolein formation occurs by glycerol dehydration. Due to the high glycerol surplus, several studies encourage its conversion into higher-added-value compounds. Furthermore, it illustrates how previous studies in the oxidation of acrolein aimed to develop glycerol oxidehydration, which is the conversion of glycerol into acrolein and its oxidation into acrylic acid in the same catalytic step.
BEST PRACTICES AND PITFALLS IN THE MEASUREMENTS OF THE CATALYTIC ACTIVITY OF MATERIALS IN THERMO-CATALYSIS Leandro Martins, Laura Silva, Luiz Possato Quimica Nova, 2024 BEST PRACTICES AND PITFALLS IN THE MEASUREMENTS OF THE CATALYTIC ACTIVITY OF MATERIALS IN THERMO-CATALYSIS. As catalysis grows as a multidisciplinary research area, many questions arise regarding the procedures used to determine the activity of materials in different chemical reactions. To correct inconsistencies, whether in definitions, concepts, or experimental methods, some catalysis science journals have been publishing editorials warning less-aware authors. In this work, we present some common concepts and procedures in thermo-catalysis, reviewing good practices and pointing out frequent failures that make it difficult to reliably compare the activity between materials of the same family and results from the scientific literature.
5th Technical Meeting of POSMAT Luiz G. Possato, Wallance M. Pazzin, Diego R. N. Corrêa Materials Research, 2024 University, in Bauru, Brazil.The event was organized by the Postgraduate Program in Materials Science and Technology (POSMAT) 1 .The event has been established as an important platform for discussion and advancement in the field of materials research, bringing together researchers, industry professionals, and students to share knowledge, technological advancements, and future perspectives for the sector.The event featured short courses taught by technical experts from partner companies such as Horiba, Anton Paar, and Metrohm, as well as presentations by master's and doctoral students from the program and undergraduate research students, in both oral and poster formats.A total of 147 participants registered for the event, including 43 undergraduate research students (~30%), 94 researchers (including graduate students and professors), and 10 invited speakers.It is important to emphasize that among these 94 registered researchers, 14 are professors accredited by the program, while the majority of the remaining participants are graduate students.The synergy between students and renowned researchers was one of the most remarkable aspects of the meeting, fostering a dynamic environment for meaningful discussions, groundbreaking collaborations, and innovative projects.We firmly believe that such interactions play a pivotal role in accelerating innovation and technological progress, ultimately benefiting the entire materials science ecosystem.We would like to express our sincere gratitude to all professionals, organizing committee members, paper reviewers, moderators, and vice-moderators of the technical sessions who, with their knowledge and dedication, helped ensure the scientific quality of the event.We also extend our thanks to our partners and sponsors, whose support was essential for the realization of this meeting.Finally, we would like to express our gratitude to all participants who contributed, directly or indirectly, to the success of the 5th Technical Meeting of POSMAT.It was a privilege to have each of you with us, and we look forward to seeing you at the next edition, which will take place in 2025 in Presidente Prudente.Thank you very much!
Synthesis of MgO Using the Sol-gel Method: Correlation Between CTAB Surfactant Concentration and MgO Properties Gabriel R. Silva, Matheus S. Assis, João C. P. de Souza, Luiz G. Possato Materials Research, 2024 In this work, the surfactant cetyltrimethylammonium bromide (CTAB) was applied to observe how increasing the surfactant's concentration will affect the MgO characteristics, such as the increase in vacancies. The samples were characterized by X-ray diffraction (XRD). For the MgO-0.025CTAB sample, the intensity of the (200) peak of MgO decreased by three. However, the MgO-2.5CTAB showed an increase in the peaks intensity. In addition to using Rietveld refinement, it is possible to observe the textural characteristics of the samples, with the introduction of CTAB, oxygen vacancies increased, and from the MgO to the MgO-0.025CTAB sample, there was a decrease in oxygen occupancy from 94% to 82% in the unit cell. Thermogravimetry (TG) analyses were used to understand the interactions between the support and the surfactant as the CTAB concentration increased. With the physisorption of N2, the behavior of the sample pores and specific area determination are verified. The introduction of CTAB caused the decrease of the specific area from 32 m2/g to 9 m2/g for the MgO and MgO-0.025CTAB samples. However, for a more concentrated surfactant, MgO-2.5CTAB, the specific area was 25 m2/g. Scanning electron microscopy made it possible to observe the increase in the roughness with CTAB presence.
Evaluation of Properties Changes by the Addition of Surfactant in the Synthesis of Ni/CeO2 Lucas S. Ricci, Marcela A. Lucas, João C.P. de Souza, Luiz G. Possato Materials Research, 2024 This work evaluates how adding cetyltrimethylammonium bromide (CTAB) in the synthesis affects the physical and chemical features of Ni/CeO2 catalysts. The samples were characterized by the Rietveld refinement from X-ray diffraction (XRD) and showed a decrease in the crystallite size and an increase in the microstrain from 5.9 to 7.5 x 10-3. Nitrogen physisorption analysis was used to obtain the pore size distribution by the BJH method, varying the pore size between 8 and 12 nm. Raman spectroscopy was employed to confirm the fluorite structure arrangement of ceria and the number of vacancies in the bulk phase, where the ratio from vibrational modes related to defects and oxygen vacancies increased from 0.488 to 0.516 ratio. With the spectra obtained from X-ray photoelectron spectroscopy (XPS), it was possible to observe the distribution of metals on the surface of the samples and their oxidative states, providing clues about the quantity of vacancies. Samples with higher concentrations of CTAB obtained higher values of Ce3+, reaching a 0.45 ratio on the surface. The scanning electron microscopy (SEM) analysis showed that the addition of CTAB formed more irregular shape grains, reaching 20 μm of medium size for all the samples.
Operando XAS and Raman investigation of defect-rich CTAB-derived Ni/CeO2 catalysts for CO2 methanation LS Ricci, PN Lisboa-Filho, V Briois, LG Possato Journal of Energy Chemistry , 2026 2026
Espectroscopia Raman Operando e Insights de XAS sobre Catalisadores Ni/CeO2 Ricos em Vacâncias de Oxigênio para Metanação de CO2 L Ricci, L Possato 23º CBCAT–Congresso Brasileiro de Catalise 1 (1) , 2025 2025
Conversão de metano a metanol sobre zeólitas oxo-Cu2+-Y geradas por ativação com He ou ar. Análise da natureza e atividade dos oxo-cátions por análises DRS-UV-vis in situ e … ES da Silva, CHF da Cunha, JMC Bueno, LG Possato, EAU Gonzalez 23º CBCAT–Congresso Brasileiro de Catalise 1 (1) , 2025 2025
Estudos espectroscópicos in situ e operando de catalisadores para a redução de CO2 LG Possato, MS Assis, Á dos Santos Leonardo 23º CBCAT–Congresso Brasileiro de Catalise 1 (1) , 2025 2025
Síntese e caracterização de estruturas ZIF-8 de Ni2+ e Zn2+ amino modificados GA Da Silva, JPD Querino, LG Possato 23º CBCAT–Congresso Brasileiro de Catalise 1 (1) , 2025 2025
Avaliação operando de catalisadores NiCeO2 por espectroscopia Raman A Leonardo, LG Possato 23º CBCAT–Congresso Brasileiro de Catalise 1 (1) , 2025 2025
Planejamento Experimental com Delineamento Composto Central para a Otimização de Catalisadores Ni/CeO2 para a redução de CO2 MS De Assis, LG Possato 23º CBCAT–Congresso Brasileiro de Catalise 1 (1) , 2025 2025
Sonochemical Defect Engineering for Sustainable CO 2 Methanation over Ni/CeO 2 Catalysts with Mechanistic Insights from Operando Studies MA Lucas, PN Lisboa‐Filho, LG Possato ChemistrySelect 10 (37), e04855 , 2025 2025 Citations: 1
Cover Feature: Refinement of Crystal Structure and its Application for Catalytic Materials (Eur. J. Inorg. Chem. 21/2025) GR Silva, GA Silva, JPD Querino, LG Possato European Journal of Inorganic Chemistry 28 (21), e70001 , 2025 2025
Refinement of Crystal Structure and its Application for Catalytic Materials GR Silva, GA Silva, JPD Querino, LG Possato European Journal of Inorganic Chemistry 28 (21), e202500051 , 2025 2025 Citations: 5
In situ evaluation of Ni/CeO2 catalysts synthesized via polymeric precursor method by XAS for CO2 reduction MS Assis, MA Lucas, V Briois, LG Possato Applied Catalysis B: Environment and Energy 369, 125144 , 2025 2025 Citations: 9
Fundamentals and development of oxidation catalysts: the acrylic acid manufacture case LH Vieira, L Martins, LG Possato Catalysis Reviews 67 (1), 244-281 , 2025 2025 Citations: 10
Evaluation of Properties Changes by the Addition of Surfactant in the Synthesis of Ni/CeO 2 LS Ricci, MA Lucas, JCP Souza, LG Possato Materials Research 27 (suppl. 2), e20240149 , 2024 2024 Citations: 4
Synthesis of MgO using the sol-gel method: correlation between CTAB surfactant concentration and MgO properties GR Silva, MS Assis, JCP Souza, LG Possato Materials Research 27 (suppl. 2), e20240148 , 2024 2024 Citations: 3
Boas práticas e equívocos nas medidas de atividade catalítica de materiais em termocatálise L Martins, LL Silva, LG Possato Química Nova 47 (2), e-20230099 , 2024 2024 Citations: 4
Exploiting the effect of PEO parameters on the surface of AISI 1020 low-carbon steel treated in a TaOH-rich electrolyte N Marcuz, RP Ribeiro, EC Rangel, NC Cruz, LG Possato, KS Coan, ... Surface and Coatings Technology 477, 130374 , 2024 2024 Citations: 8
5 th Technical Meeting of POSMAT LG Possato, WM Pazzin, DRN Corrêa Materials Research 27 (Suppl 2), e2024E003 , 2024 2024
BEST PRACTICES AND PITFALLS IN THE MEASUREMENTS OF THE CATALYTIC ACTIVITY OF MATERIALS IN THERMO-CATALYSIS L Martins, LL Silva, LG Possato 2024
PII. 048 Síntese e caracterização de catalisadores de Ni/CeO2 através da irradiação ultrassonica LG Possato 22° CBCAT , 2023 2023
PII. 046 Síntese de suportes básicos adquiridos pelo método sol-gel com potencial aplicação para conversão de CO2 G Silva, LG Possato 22° CBCAT , 2023 2023
MOST CITED SCHOLAR PUBLICATIONS
A comparative study of glycerol dehydration catalyzed by micro/mesoporous MFI zeolites LG Possato, RN Diniz, T Garetto, SH Pulcinelli, CV Santilli, L Martins Journal of Catalysis 300, 102-112 , 2013 2013 Citations: 193
One-step glycerol oxidehydration to acrylic acid on multifunctional zeolite catalysts LG Possato, WH Cassinelli, T Garetto, SH Pulcinelli, CV Santilli, L Martins Applied Catalysis A: General 492, 243-251 , 2015 2015 Citations: 95
The multiple benefits of glycerol conversion to acrolein and acrylic acid catalyzed by vanadium oxides supported on micro-mesoporous MFI zeolites LG Possato, TF Chaves, WH Cassinelli, SH Pulcinelli, CV Santilli, ... Catalysis Today 289, 20-28 , 2017 2017 Citations: 59
One-step oxidehydration of glycerol to acrylic acid using ETS-10-like vanadosilicates AS Paula, LG Possato, DR Ratero, J Contro, K Keinan-Adamsky, ... Microporous and Mesoporous Materials 232, 151-160 , 2016 2016 Citations: 50
Sol-gel synthesis of nanocrystalline MgO and its application as support in Ni/MgO catalysts for ethanol steam reforming LG Possato, RGL Gonçalves, RMM Santos, TF Chaves, V Briois, ... Applied Surface Science 542, 148744 , 2021 2021 Citations: 40
Thermal treatments of precursors of molybdenum and vanadium oxides and the formed MoxVyOz phases active in the oxydehydration of glycerol LG Possato, WH Cassinelli, CI Meyer, T Garetto, SH Pulcinelli, CV Santilli, ... Applied Catalysis A: General 532, 1-11 , 2017 2017 Citations: 40
Hydrothermal synthesis of Mo-V mixed oxides possessing several crystalline phases and their performance in the catalytic oxydehydration of glycerol to acrylic acid LF Rasteiro, LH Vieira, LG Possato, SH Pulcinelli, CV Santilli, L Martins Catalysis Today 296, 10-18 , 2017 2017 Citations: 39
Activation of Mo and V oxides supported on ZSM-5 zeolite catalysts followed by in situ XAS and XRD and their uses in oxydehydration of glycerol LG Possato, MD Acevedo, CL Padró, V Briois, AR Passos, SH Pulcinelli, ... Molecular Catalysis 481, 110158 , 2020 2020 Citations: 35
Progress of the Catalytic Deactivation of H‐ZSM‐5 Zeolite in Glycerol Dehydration GL Catuzo, LG Possato, ME Sad, C Padro, L Martins ChemCatChem 13 (20), 4419-4430 , 2021 2021 Citations: 30
Studies on dispersion and reactivity of vanadium oxides deposited on lamellar ferrierite zeolites for condensation of glycerol into bulky products LH Vieira, LG Possato, TF Chaves, SH Pulcinelli, CV Santilli, L Martins Molecular Catalysis 458, 161-170 , 2018 2018 Citations: 30
Controlling the porosity and crystallinity of MgO catalysts by addition of surfactant in the sol-gel synthesis LG Possato, E Pereira, RGL Goncalves, SH Pulcinelli, L Martins, ... Catalysis Today 344, 52-58 , 2020 2020 Citations: 22
Synthesis and characterization of chromium silicate catalyst and its application in the gas phase glycerol transformation into acetaldehyde RA Luizon Filho, LG Possato, OAN Santisteban, A de Vasconcellos, ... Inorganic Chemistry Communications 112, 107710 , 2020 2020 Citations: 18
Insights into redox dynamics of vanadium species impregnated in layered siliceous zeolitic structures during methanol oxidation reactions LH Vieira, LG Possato, TF Chaves, JJ Lee, TP Sulmonetti, CW Jones, ... ChemCatChem 12 (1), 141-151 , 2020 2020 Citations: 13
Fundamentals and development of oxidation catalysts: the acrylic acid manufacture case LH Vieira, L Martins, LG Possato Catalysis Reviews 67 (1), 244-281 , 2025 2025 Citations: 10
In situ evaluation of Ni/CeO2 catalysts synthesized via polymeric precursor method by XAS for CO2 reduction MS Assis, MA Lucas, V Briois, LG Possato Applied Catalysis B: Environment and Energy 369, 125144 , 2025 2025 Citations: 9
Exploiting the effect of PEO parameters on the surface of AISI 1020 low-carbon steel treated in a TaOH-rich electrolyte N Marcuz, RP Ribeiro, EC Rangel, NC Cruz, LG Possato, KS Coan, ... Surface and Coatings Technology 477, 130374 , 2024 2024 Citations: 8
Appraisal of Ni species supported on porous MgO during ethanol steam reforming by XAS LG Possato, SH Pulcinelli, L Martins, V Briois, CV Santilli ChemCatChem 14 (21), e202200684 , 2022 2022 Citations: 8
Refinement of Crystal Structure and its Application for Catalytic Materials GR Silva, GA Silva, JPD Querino, LG Possato European Journal of Inorganic Chemistry 28 (21), e202500051 , 2025 2025 Citations: 5
Evaluation of Properties Changes by the Addition of Surfactant in the Synthesis of Ni/CeO 2 LS Ricci, MA Lucas, JCP Souza, LG Possato Materials Research 27 (suppl. 2), e20240149 , 2024 2024 Citations: 4
Boas práticas e equívocos nas medidas de atividade catalítica de materiais em termocatálise L Martins, LL Silva, LG Possato Química Nova 47 (2), e-20230099 , 2024 2024 Citations: 4