Article
Chemistry, Physical
Katarzyna Stawicka, Maciej Trejda, Maria Ziolek
Summary: Niobium-containing SBA-15 catalysts prepared by different methods exhibit varying acidity properties, with niobium incorporation into the SBA-15 framework being crucial for high catalytic performance. Silanization can reduce the number of acidic sites on the catalysts and significantly enhance acrolein yield and selectivity.
Article
Chemistry, Applied
Shan Liu, Zhiquan Yu, Yao Wang, Zhichao Sun, Yingya Liu, Chuan Shi, Anjie Wang
Summary: Catalytic dehydration of glycerol over MoP catalyst can achieve high selectivity for acrolein, up to 89.0%. The selectivity remained constant in a 50-hour run at 240 degrees C, but the glycerol conversion gradually decreased.
Review
Green & Sustainable Science & Technology
Anas Abdullah, Ahmad Zuhairi Abdullah, Mukhtar Ahmed, Junaid Khan, Mohammad Shahadat, Khalid Umar, Md Abdul Alim
Summary: The catalytic dehydration of glycerol to acrolein is a promising research topic with commercial prospects. Recent studies have focused on reducing catalyst deactivation, improving catalyst stability, and optimizing reaction parameters. Promising results have been achieved through altering catalyst structure, introducing new techniques and methods.
JOURNAL OF CLEANER PRODUCTION
(2022)
Article
Engineering, Environmental
Jianfeng Shan, Zhikai Li, Zheng Chen, Dengfeng Wang, Xuelan Zhang, Zihan Ning, Yanfeng Xue, Shanhui Zhu
Summary: HZSM-5 zeolites modified by phosphoric acid impregnation were used for acrolein production from glycerol. The phosphorus modified nanosheet HZSM-5 showed excellent catalytic performance with high glycerol conversion and acrolein selectivity, as well as improved stability. The addition of phosphorus adjusted the acidity of HZSM-5 zeolite, suppressed coke formation, and prolonged the catalyst lifetime. In addition, diffusion restriction of products played a crucial role in achieving high acrolein selectivity.
CHEMICAL ENGINEERING JOURNAL
(2023)
Review
Chemistry, Multidisciplinary
Tianlin Ma, Manyun Yin, Chunyang Su, Ningfei Guo, Xiangxiang Huang, Zhen Han, Yujie Wang, Gangling Chen, Zhi Yun
Summary: The surplus production of glycerol as a byproduct of biodiesel has become a pressing issue for the sustainability of the industry. The catalytic transformation of glycerol to value-added chemicals, particularly acrolein, has gained significant attention. Molecular sieves are considered promising catalysts for industrial applications, but a systematic summary on the research carried out for this reaction is lacking. This review provides a comprehensive and critical overview of glycerol dehydration to acrolein over various molecular sieve catalysts, discussing key technical problems and factors influencing the dehydration performance, as well as the reaction mechanism, kinetics, thermodynamics, and future research directions.
JOURNAL OF INDUSTRIAL AND ENGINEERING CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Ismail Boz, Mehtap Safak Boroglu, Yasar Zengin, Busra Kaya
Summary: The effects of the addition of colloidal silica and solvents on the activity and stability of WO3-TiO2 catalysts in glycerol oxy-dehydration were investigated. WO3 supported cSiO(2)-TiO2 catalysts exhibited high stability and selectivity. The addition of colloidal silica onto TiO2 support resulted in the highest medium strength acidity and optimum Bronsted to Lewis acid site ratio of WO3 catalysts, leading to improved acrolein selectivity and stability.
KOREAN JOURNAL OF CHEMICAL ENGINEERING
(2023)
Article
Engineering, Chemical
A. C. Dimian, C. S. Bildea
Summary: This paper investigates the conceptual design of an eco-efficient process using renewable low-cost glycerol for producing acrylic acid, comparing the efficiency and energy consumption of different types of fluidized bed reactors. It was found that using CFB reactors can achieve higher productivity and lower energy consumption.
CHEMICAL ENGINEERING RESEARCH & DESIGN
(2021)
Article
Chemistry, Applied
Zhiheng Wang, Licheng Liu
Summary: In this study, tungsten-based heteropolyacids supported on non-ordered mesoporous silica were investigated as catalysts for glycerol dehydration to acrolein. Characterization and analysis revealed the surface structure of HPA, the acidic properties, and the correlation between acidic properties and dehydration activity. The results showed that acrolein yield increased with H3PW12O40 loading until 30 wt%, discussing the active role of Bronsted acid and the cooperative role of Bronsted/Lewis acid sites for glycerol dehydration to acrolein.
Article
Engineering, Chemical
Dirleia S. Lima, Oscar W. Perez-Lopez
Summary: Mesoporous alumina was prepared by varying crystallization time and acid concentration, and evaluated in glycerol dehydration. The specific surface area, crystallinity, and acidic properties of the samples were dependent on both the crystallization time and acid concentration. The catalytic properties were related to the specific surface area and acidic characteristics, with conversions of glycerol above 92% obtained for all samples.
Article
Chemistry, Applied
Busra Kaya, Yasar Zengin, Mehtap Safak Boroglu, Ismail Boz
Summary: By characterizing the tungsten oxide catalyst, it was found that the medium-strength surface acidity and mesoporous structure play a crucial role in the selective dehydration of glycerol to acrolein.
JOURNAL OF POROUS MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Yutong Zhu, Xiaofei Xu, Jian He, Jie Guo, Ke Song
Summary: In this study, mesoporous Ti-SBA-15 catalysts were synthesized and their catalytic performance in the conversion of fructose to HMF was investigated. High yields of HMF could be obtained by adjusting the Si/Ti ratio and reaction conditions, and the catalyst exhibited good stability.
FRONTIERS IN CHEMISTRY
(2022)
Article
Chemistry, Physical
Jianfeng Shan, Yanfeng Xue, Dengfeng Wang, Zheng Chen, Shanhui Zhu
Summary: The study demonstrated that Pd/CoOx catalyst showed high ethanol selectivity and reusability in direct hydrogenolysis of glycerol to ethanol, with the assistance of Cu/SBA-15 as co-catalyst to enhance ethanol yield and inhibit catalyst aggregation. Synergistic catalysis of Pd/CoOx and Cu/SBA-15 achieved a record ethanol yield of 84.5% in glycerol hydrogenolysis reactions.
APPLIED CATALYSIS B-ENVIRONMENTAL
(2022)
Article
Chemistry, Applied
J. E. Castanheiro, J. Vital, I. M. Fonseca, A. M. Ramos
Summary: The acetalization of glycerol with hexanal was studied using sulfonic acid-functionalized mesoporous silica, showing optimal activity when the amount of sulfonic acid groups was moderate. Activity increased with the number of sulfonic acid groups until reaching a maximum, after which a decrease was observed. The catalytic stability of the [SO3H](3)-SBA-15 catalyst was evaluated through consecutive batch runs, demonstrating good stability.
Article
Chemistry, Applied
Wesley Eul, Antonio Marcelo Silva Lopes, Sibele B. C. Pergher, Tiago Pinheiro Braga
Summary: The synthesis and characterization of cobalt ferrite supported on mesoporous SBA-15 were investigated for the glycerol conversion reaction in the presence of ethanol. Characterization techniques confirmed the successful synthesis of SBA-15 and dispersed CoFe2O4 phase. The redox property and acid-base characteristics of the catalyst were evaluated, showing promising catalytic performance with ethanol as a co-reagent.
MICROPOROUS AND MESOPOROUS MATERIALS
(2023)
Article
Energy & Fuels
Nurul Asmawati Roslan, Nur Nabillah Mohd Arif, Jessy Lynn Jaspin, Nurul Aini Mohamed Razali, Sumaiya Zainal Abidin
Summary: This study presents the glycerol dry reforming (GDR) reaction using rhenium (Re) promoted on Ni-based catalyst supported on Santa Barbara Amorphous 15 (SBA-15) for the production of hydrogen. It was found that the addition of 3%Re to 15%Ni/SBA-15 catalyst significantly improved the glycerol conversion and hydrogen yield due to the small crystallite size and BET surface area, which effectively reduced carbon deposition.
ENERGY SOURCES PART A-RECOVERY UTILIZATION AND ENVIRONMENTAL EFFECTS
(2022)
Article
Chemistry, Applied
Duarte M. Cecilio, Maria L. Cerrada, Ernesto Perez, Auguste Fernandes, Joao Paulo Lourenco, Timothy F. L. McKenna, M. Rosario Ribeiro
Summary: Materials prepared using the DS-SA method exhibit superior filler dispersion and significantly higher mechanical performance at high filler loadings compared to their DS-MAO counterparts, while still retaining the ultimate stretching ability of HDPE.
MICROPOROUS AND MESOPOROUS MATERIALS
(2022)
Article
Physics, Particles & Fields
Ivo de Medeiros Varzielas, Joao Lourenco
Summary: We present a lepton flavor model based on two A4 modular symmetries, where a bi-triplet field breaks the two A4 symmetries to the diagonal A4 subgroup and results in an effective modular A4 flavor symmetry with two moduli. The moduli are employed as stabilizers, which preserve distinct residual symmetries and enable us to obtain Tri-Maximal 2 (TM2) mixing with minimal field content below the breaking scale to the single A4.
Article
Polymer Science
Duarte M. Cecilio, Maria L. Cerrada, Ernesto Perez, Auguste Fernandes, Joao Paulo Lourenco, Timothy F. L. McKenna, M. Rosario Ribeiro
Summary: A novel supported activator (SA) approach utilizing nano-sized supported methylaluminoxane (MAO)-activator based on halloysite natural nanotubes (HNT) and an in situ supporting concept is developed for the preparation of high density polyethylene (HDPE)-based highly performant hybrid materials. The SA method shows enhanced polymerization activities and generates ultimate materials with improved morphological features, greater crystallinity, thicker crystals, and significantly increased stiffness. The use of high aspect ratio support like HNT also contributes to better mechanical properties compared to similar HDPE hybrid materials derived from dendrimer-like silica (DS) nanospheres.
EUROPEAN POLYMER JOURNAL
(2023)
Article
Chemistry, Applied
Ana Grenha, Filipa Guerreiro, Joao P. Lourenco, Joao Almeida Lopes, Fernando Camara-Martos
Summary: This study demonstrates the potential of microencapsulation to improve the bioaccessibility of selenium in a food matrix. Microencapsulation with mannitol or mannitol/gastro-resistant polymer significantly enhanced the bioaccessibility of selenium, with values reaching up to 40% after the gastric phase and 55% after the intestinal phase.
Article
Chemistry, Applied
Sara El Kharraf, Abdellah Farah, Soukaina El-Guendouz, Joao P. Lourenco, Ana M. Rosa Costa, El Mestafa El Hadrami, Alexandra M. Machado, Claudia S. Tavares, A. Cristina Figueiredo, M. Graca Miguel
Summary: A combined volatile oil from Rosmarinus officinalis, Lavandula angustifolia and Citrus aurantium was encapsulated in beta-cyclodextrin using co-precipitation method. Response surface methodology was applied to optimize microencapsulation conditions and investigate the variables affecting the encapsulation process. The release of volatile oil from the inclusion complexes was studied using different solutions. The Higuchi model provided the best fit for the release profile, indicating Fickian diffusion as the predominant mechanism of release.
JOURNAL OF ESSENTIAL OIL RESEARCH
(2023)
Article
Oncology
Vladimir Wischnewski, Roeltje R. Maas, Paola Guerrero Aruffo, Klara Soukup, Giovanni Galletti, Mara Kornete, Sabine Galland, Nadine Fournier, Johanna Lilja, Pratyaksha Wirapati, Joao Lourenco, Alice Scarpa, Roy T. Daniel, Andreas F. Hottinger, Jean-Philippe Brouland, Agnese Losurdo, Emanuele Voulaz, Marco Alloisio, Monika E. Hegi, Enrico Lugli, Johanna A. Joyce
Summary: The authors used T cell profiling in brain tumor samples to understand the biology and therapeutic relevance of the brain tumor microenvironment. They found a tissue-specific conflict between immune suppression and immune activation in brain tumors, which can inform stratification for immunotherapy. Their analysis revealed differences in T cell biology between individuals, with a subgroup of brain metastases showing accumulation of potentially tumor-reactive T cells.
Article
Automation & Control Systems
Nuno Costa, Joao Lourenco
Summary: Researchers and practitioners often face problems with multiple objectives that have conflicting solutions and no unique solution. This paper proposes a novel metric to assess the resilience of Pareto solutions to avoid wasting resources and time on solutions that do not produce the expected outcomes.
CHEMOMETRICS AND INTELLIGENT LABORATORY SYSTEMS
(2023)
Article
Chemistry, Physical
Maria L. Cerrada, Artur Bento, Ernesto Perez, Joao P. Lourenco, M. Rosario Ribeiro
Summary: Functionalized polyethylene-based nanocomposites were prepared by in situ polymerization of ethylene with modified or neat MCM-41 nanoparticles. Two different synthetic approaches, one incorporating UA into the polymeric matrix and the other using UA as an interfacial agent, were investigated to improve the compatibility between the hydrophobic HDPE matrix and the hydrophilic NMCM-41. The influence of UA presence on the polymerization behavior and the thermal behavior and structural details of the resulting materials were characterized. The impact of using neat or functionalized NMCM-41 on the final dispersion within the polymeric matrix and the mechanical performance exhibited by these nanocomposites were also analyzed.
Article
Environmental Sciences
Amir Nobahar, Joao Paulo Lourenco, Maria Clara Costa, Jorge Dias Carlier
Summary: This study investigates the potential of plant extracts from Rubus idaeus L., Cistus ladanifer L., and Erica andevalensis in metal separation. The results show that the extracts from R. idaeus and E. andevalensis have a separation rate of more than 95% for Au(III), while C. ladanifer has a separation rate of 78%. When applied to real Au-bearing leachate obtained from PCB leaching, the R. idaeus extract has the highest gold recovery rate of 96%.
WASTE AND BIOMASS VALORIZATION
(2023)
Correction
Mathematics, Applied
Joao Lourenco
FORUM OF MATHEMATICS SIGMA
(2023)
Article
Mathematics, Applied
Joao Lourenco
Summary: This paper generalizes the previous works on twisted affine Grassmannians to the wildly ramified case, with mild assumptions. It constructs smooth affine $\mathbb {Z}[t]$-groups with connected fibers of parahoric type, motivated by previous work of Tits. The resulting $\mathbb {F}_p(t)$-groups are pseudo-reductive and sometimes non-standard, and their $\mathbb {F}_p [\hspace{-0.5mm}[ {t} ]\hspace {-0.5mm}]$-models are parahoric in a generalized sense. The paper also studies their affine Grassmannians and proves the normality of Schubert varieties and Zhu's coherence theorem.
FORUM OF MATHEMATICS SIGMA
(2023)
