Article
Chemistry, Physical
Ayesha A. Alkhoori, Omer Elmutasim, Aasif A. Dabbawala, Michalis A. Vasiliades, Klito C. Petallidou, Abdul-Hamid Emwas, Dalaver H. Anjum, Nirpendra Singh, Mark A. Baker, Nikolaos D. Charisiou, Maria A. Goula, Angelos M. Efstathiou, Kyriaki Polychronopoulou
Summary: In this study, the Ni/CeO2/Al2O3 catalyst system was investigated to understand how different synthesis parameters affect interfacial phenomena and CO2 methanation. Key factors such as alumina texture, ceria loading, and synthesis method of supported Ni were examined to determine their influence on catalyst activity and CH4 selectivity. Among the studied catalysts, Ni-20Ce/mpAl showed promising results with high CO2 conversion rate (70%) and CH4 selectivity (>94%) at 350°C. The researchers found that medium- and high-porosity alumina facilitated better dispersion of ceria, while Ni-CeO2 cogrowth resulted in small Ni crystallites that increased in size over the course of the reaction. This catalyst exhibited advantageous features for CO2 methanation, including a high concentration of oxygen vacancies, significant presence of surface Ce3+ species, and strong CO activation capability.
ACS APPLIED ENERGY MATERIALS
(2023)
Article
Physics, Applied
A. Parastaev, N. Kosinov, E. J. M. Hensen
Summary: Plasma-enhanced heterogeneous catalysis is a promising alternative to thermal catalysis for industrial processes, but there is limited mechanistic understanding of the interactions between highly energetic electrons and excited molecules with solid catalysts in a plasma. The novel operando infrared spectroscopy cell allows for investigation of surface intermediates on a catalyst exposed to a plasma at room temperature. This combined approach offers new experimental insights into plasma-catalyst synergy, demonstrating CO2 methanation at the catalyst surface in a plasma at room temperature.
JOURNAL OF PHYSICS D-APPLIED PHYSICS
(2021)
Article
Chemistry, Applied
J. P. Dacquin, S. Troncea, V. Parvulescu, P. Granger
Summary: This study investigates the kinetics of successive ammonia production and consumption during the catalytic water denitrification process over Pd/CexZr1-xO2 catalysts. The fast conversion of nitrites to ammonium ions is found to be weakly dependent on palladium particle size, while subsequent slow consumption of ammonia in anaerobic conditions highlights the importance of ammonia oxidation reaction with a pseudo rate constant depending on the surface coverage of reactive oxygen from ceria. The study emphasizes the significance of the synthesis route of CexZr1-xO2 and its peculiar interaction with Pd in the overall reaction kinetics.
Article
Chemistry, Physical
Yixiao Wang, Jorrit Postuma de Boer, Michiel Makkee
Summary: The study investigates the application of Rh/CLZ catalyst in reducing N2O from industrial exhaust streams, revealing that hydrocarbon pretreatment enhances catalyst activity and explaining the reaction mechanism. The results demonstrate a unique N2O abatement performance in the presence of competing oxidants.
CATALYSIS SCIENCE & TECHNOLOGY
(2021)
Article
Thermodynamics
Zuo Li, Mohamed N. Marei, Assaad R. Masri, Alejandro Montoya
Summary: The reduction mechanism of NO to N-2 on CeO2-supported Pt and Pd nanoclusters (Pt/CeO2 and Pd/CeO2) was analyzed using density functional theory. Different pathways for NO decomposition and N-2 formation were evaluated, and the thermodynamically preferable paths were identified. The energy barrier of NO decomposition on Pt/CeO2 suggests comparable reactivity via metallic cluster sites and ceria oxygen vacancies, while Pd/CeO2 exhibited lower energy barriers for NO decomposition at the cluster metallic sites compared to the oxygen CeO2 vacancy sites. N-2 formation on Pt/CeO2 occurred preferentially through N-N association, whereas N2O deoxidation was energetically preferred on Pd/CeO2.
COMBUSTION SCIENCE AND TECHNOLOGY
(2023)
Article
Chemistry, Multidisciplinary
Jack J. Quayle, Alexandros P. Katsoulidis, John B. Claridge, Andrew P. E. York, David Thompsett, Matthew J. Rosseinsky
Summary: This study utilizes a high-throughput robotic synthesis route combined with automated characterization techniques to rapidly predict the oxygen storage capacity (OSC) of new materials, accelerating the discovery and development of catalysts. The method can be used for efficient screening of high-capacity oxygen storage materials and motivates the use of similar high-throughput workflows for catalyst screening in other heterogeneous transformations.
Article
Chemistry, Physical
Oleg A. Usoltsev, Alina A. Skorynina, Bogdan O. Protsenko, Vlad Martin-Diaconescu, Riccardo Pellegrini, Alexander Soldatov, Jeroen van Bokhoven, Aram L. Bugaev
Summary: This study establishes a systematic investigation of the evolution of the atomic and electronic structure in alumina-and carbon-supported palladium nanoparticles in the presence of CO and CH4 gases. The immediate adsorption of CO molecules and the active formation of bulk palladium carbide were observed at different temperatures, while the latter process in CH4 started at a higher temperature. The reduction of palladium and the contraction of interatomic distances occurred with increasing temperature, regardless of the gas atmosphere, particle size, and support type. For carbon-supported samples, the formation of palladium carbide occurred above a certain temperature due to the decomposition of the support.
APPLIED SURFACE SCIENCE
(2023)
Article
Engineering, Environmental
Chunxiao Yang, Kexin Zhang, Yankun Zhang, Guo Jian Peng, Meng Yang, Junjie Wen, Yu Xie, Futing Xia, Lijuan Jia, Qiulin Zhang
Summary: A series of Ce/Fe-Zr-SO42- catalysts have been developed for selective catalytic reduction of NO with ammonia. Among them, Ce/Fe-Zr-0.3 S catalyst showed the optimal NOx conversion at 250 degrees C with a sulfuric acid concentration of 0.3 mol/L.
JOURNAL OF ENVIRONMENTAL CHEMICAL ENGINEERING
(2021)
Article
Chemistry, Physical
Anna Cooper, Stan Golunski, Stuart H. Taylor
Summary: The addition of potassium to the catalyst has an impact on the relationship between NOx reduction and soot oxidation. Lower potassium loadings can promote NOx reduction without affecting soot oxidation, while higher loadings almost completely disable NOx reduction and only contribute to the activity of the catalyst in the presence of soot. At a loading of 20% potassium, the potassium phase segregates, exposing other reaction sites.
Article
Chemistry, Physical
Jawaher Mosrati, Ali M. Abdel-Mageed, Thanh Huyen Vuong, Reni Grauke, Stephan Bartling, Nils Rockstroh, Hanan Atia, Udo Armbruster, Sebastian Wohlrab, Jabor Rabeah, Angelika Brueckner
Summary: Cu single-atom catalysts supported on CeO2-TiO2 were prepared using a sol-gel method and showed high efficiency and stability in CO oxidation. Spectroscopic methods such as infrared, electron paramagnetic resonance, and X-ray photoelectron spectroscopy revealed the mechanism of action and structure-reactivity relationships.
Article
Chemistry, Physical
Houda Maati, Othmane Amadine, Younes Essamlali, Boutaina Rezki, Ikram Ayouch, Hassan Mahi, Karima Abdelouahdi, Mohamed Zahouily
Summary: A palladium ceria-zirconia Pd0.05Ce0.5Zr0.475O2 catalytic based nanomaterial was synthesized and characterized. Compared to other materials, Pd0.05Ce0.5Zr0.475O2 exhibited the highest BET surface area and showed high catalytic activity and stability for aryl bromides without the use of any ligand.
JOURNAL OF MOLECULAR STRUCTURE
(2023)
Article
Chemistry, Physical
Maila Danielis, Luis E. Betancourt, Ivan Orozco, Nuria J. Divins, Jordi Llorca, Jose A. Rodriguez, Sanjaya D. Senanayake, Sara Colussi, Alessandro Trovarelli
Summary: The milling of Palladium acetate and CeO2 under dry conditions results in robust and environmentally friendly catalysts with excellent methane oxidation activity. The characterization techniques used in this study identified the presence of Pd-0/Pd2+ species with different degrees of interaction with ceria (Ce3+/Ce4+), which are believed to be responsible for the enhanced catalytic activity. This study provides insight into the mechanistic understanding of the catalytic performance of Pd/CeO2 catalysts prepared by dry milling.
APPLIED CATALYSIS B-ENVIRONMENTAL
(2021)
Article
Energy & Fuels
Shumei Chen, Chao Miao, Lixing Liang, Jing Ouyang
Summary: This paper reports the synthesis and CO2 methanation performance of Ni/CeO2-ZrO2 solid solutions assembled on different clay minerals. The Ni-CZA catalyst assembled on attapulgite showed the highest CO2 conversion and excellent stability due to its excellent adsorption performance and large specific surface area.
Article
Chemistry, Physical
E. S. Lokteva, V. V. Shishova, K. I. Maslakov, E. V. Golubina, A. N. Kharlanov, I. A. Rodin, M. F. Vokuev, D. S. Filimonov, N. N. Tolkachev
Summary: Monometallic palladium and bimetallic palladium-iron catalysts were prepared using sequential and co-impregnation methods. The bimetallic catalysts showed higher efficiency in hydrodechlorination reaction compared to the monometallic Pd catalysts. The co-impregnation method resulted in better catalyst performance. The improved efficiency was attributed to wider pores, formation of PdFe alloys or Pd-Fe-Ox species on the surface, high Pd0/Pd2 ratio, low extent of Pd encapsulation, and coordinately unsaturated sites.
APPLIED SURFACE SCIENCE
(2023)
Article
Chemistry, Physical
Iraida N. Demchenko, Kostiantyn Nikiforow, Maryna Chernyshova, Yevgen Melikhov, Yevgen Syryanyy, Nadiia Korsunska, Larysa Khomenkova, Yehor Brodnikovskyi, Dmytro Brodnikovskyi
Summary: This work investigates the electronic structure modification of scandia-ceria stabilized zirconia (10Sc1CeSZ) ceramics sintered at different temperatures. Through XRD, SEM, impedance spectroscopy, and XPS analysis, it was found that the increase in sintering temperature led to higher grain ionic conductivity, accompanied by reduced porosity, increased grain size, and a shift from rhombohedral to cubic phase. XPS also revealed a surface modification in the ceramic, with the lower sintering temperature showing more Zr-OH bonds.
Article
Chemistry, Applied
Arthur H. A. Goncalves, Pedro H. C. Sicilian, Odivaldo C. Alves, Deborah Cesar, Cristiane A. Henriques, Alexandre B. Gaspar
TOPICS IN CATALYSIS
(2020)
Article
Chemistry, Physical
Rodrigo Brackmann, Odivaldo Cambraia Alves, Carla Brandao Woyames, Fabio Souza Toniolo, Martin Schmal
APPLIED CATALYSIS A-GENERAL
(2020)
Article
Chemistry, Analytical
Fernanda Nunes Ferreira, Ana Paula Benevides, Deborah Vargas Cesar, Aderval S. Luna, Jefferson Santos de Gois
MICROCHEMICAL JOURNAL
(2020)
Article
Chemistry, Multidisciplinary
Jessica Rabelo do Nascimento, Monique Ribeiro D'Oliveira, Amanda Garcez Veiga, Carlos Alberto Chagas, Martin Schmal
Review
Chemistry, Multidisciplinary
Luciana Resende Marcelo, Jefferson Santos de Gois, Alexsandro Araujo da Silva, Deborah Vargas Cesar
Summary: Iron-based magnetic nanomaterials are promising adsorbents for pollutant removal in water and wastewater treatment, focusing on toxic elements, pharmaceuticals, and pesticides. Common methods for synthesis include coprecipitation, solvothermal, and hydrothermal methods, with magnetite being the most commonly used magnetic nanoparticle. The adsorption process follows Langmuir isothermal model and kinetic patterns are described by pseudo-second-order equations, showing promising performances for pollutant removal.
ENVIRONMENTAL CHEMISTRY LETTERS
(2021)
Article
Chemistry, Physical
K. T. de C. Roseno, R. A. Antunes, R. M. B. Alves, M. Schmal
Summary: The precursors of NCN and NFN catalysts were synthesized and characterized, showing an orthorhombic structure with elements like Nd, Cr or Fe, Ni and O evenly dispersed on the surface. XPS analysis revealed different states of nickel, iron and chromium in the catalysts. The methane tri-reforming reactions showed improved conversion rates and H-2/CO ratios for both catalysts under varying conditions at 850 degrees Celsius.
Article
Chemistry, Physical
Rubens W. S. Lima, Thiago L. R. Hewer, Rita M. B. Alves, Martin Schmal
Summary: The study revealed significant differences in the compounds adsorbed or deposited on the catalysts surface of Ni-Mo/SBA-15 and Ni-Mo/Al2O3 before and after the reaction. Carbon deposits on the SBA-15 catalyst were aliphatic simple molecules, while the alumina catalyst contained deposits of aromatic and oxygenated organic substances. Post-reaction analysis showed that the carbon deposited on NiMo/SBA-15 were mainly light polymer types like nanotubes and nanofibers, while heavier carbons like graphite formed on the alumina catalyst.
MOLECULAR CATALYSIS
(2021)
Article
Chemistry, Physical
Carlos Alberto Chagas, Martin Schmal
Summary: The effect of copper oxide species on the CuO-NiO/CeO2 structure and its influence on the preferential CO oxidation in H-2 excess reaction were investigated. The addition of Cu+ species increased the active sites and reduced the temperature of CO2 formation or selectivity. The stabilizing effect of carbonyl species inhibited the oxidation of H-2 and contributed to the superior selectivity towards CO2 at low temperatures.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2022)
Article
Green & Sustainable Science & Technology
Higor A. Garona, Fabio M. Cavalcanti, Thiago F. de Abreu, Martin Schmal, Rita M. B. Alves
Summary: This study used Machine Learning models to predict optimal reaction conditions for Fischer-Tropsch Synthesis, showing the efficacy of neural networks in predicting key variables. In comparison to recent studies, this research included more variables in the model such as catalyst support, active phase, and promoters. The Fe-based catalyst showed the highest light olefins selectivity and yield at optimal conditions, despite emitting the most carbon dioxide.
JOURNAL OF CLEANER PRODUCTION
(2021)
Article
Environmental Sciences
Auta Narjara de Brito Soares, Karina Tamiao C. Roseno, Reinaldo Giudici, Martin Schmal
Summary: This study investigated the effect of CO2 on the performance of nickel supported on LaFeO3 perovskite catalysts in the TRM process. The results showed that CO2 enhanced the hydrogen selectivity of the tri-reforming process compared to the partial oxidation reaction.
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
(2023)
Article
Engineering, Chemical
Martin Schmal, Rubens W. S. Lima, Thiago L. R. Hewer, Rita M. B. Alves
Summary: This study investigates the hydrogenation processes of bio-oils using different catalysts and supports. The results show that the SBA-15 catalysts exhibit higher activity and better performance than the alumina catalyst. The temperature also plays an important role in the conversion of guaiacol and anisole, with higher conversions observed at 300 degrees C. The Ni-Mo/SBA-15 catalyst at 200 degrees C shows the best results for the HDO deoxygenation of the guaiacol and anisole mixture (96.5%).
BRAZILIAN JOURNAL OF CHEMICAL ENGINEERING
(2023)
Article
Engineering, Chemical
Alberth Renne Gonzalez Caranton, Martin Schmal, Noemi Raquel Checca Huaman, Jose Carlos da Silva Pinto
Summary: This study prepares bimetallic PdCu catalysts supported on modified ZrO2 with Ti and Al using sol-gel and sonochemical methods. The catalysts exhibit higher activity in the synthesis of vinyl acetate. Characterization results show bimetallic species and distorted alloys dispersed onto the support. In situ reaction analysis reveals the formation of palladium acetate monomers and mono and bidentate intermediates, suggesting their involvement in vinyl acetate formation. The interaction between PdCu and the supports promotes the exposure of PdCu species, enhancing the catalytic performance.
MACROMOLECULAR REACTION ENGINEERING
(2023)
Article
Environmental Sciences
Camila Emilia Kozonoe, Vinicius Modolo Santos, Martin Schmal
Summary: This study investigated the performance of catalysts based on Ni and Fe nanoparticles selectively deposited on carbon nanotubes before and after dry methane reforming. The results showed that the nanotube structure was maintained even after acid treatment and high-temperature calcination. The catalysts exhibited high activity in dry methane reforming reactions, indicating their potential in this application.
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
(2023)
Article
Materials Science, Multidisciplinary
Ana Paula Benevides, Adriano Rocha Campos, Lanna Cristina Vieira, Cesar dos Reis Perez, Deborah Vargas Cesar
MATERIALS RESEARCH-IBERO-AMERICAN JOURNAL OF MATERIALS
(2020)
Article
Chemistry, Multidisciplinary
Adao S. Goncalves, Cristiane A. Henriques, Deborah Cesar
