Article
Engineering, Chemical
Meng-Nan Liu, Zhi-Xia Xie, Qun-Xing Luo, Jianbo Zhang, Huiyong Chen, Long Xu, Ming Sun, Xiaoxun Ma, Qing-Qing Hao
Summary: In this study, we report a facile method for the preparation of nanosized mordenite (MOR) crystals and nanoplatelets. The introduction of hexamethyleneimine (HMI) affected the morphology of MOR and the distribution of Bro''nsted acid sites. Nanosized MOR crystals prepared without HMI exhibited the highest catalytic activity due to their shorter diffusion pathway and enriched Bro''nsted acid sites.
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
(2022)
Article
Energy & Fuels
Xiao-Bo Feng, Jing-Pei Cao, Chang Su, Zi-Meng He, Xiao-Yan Zhao
Summary: In this study, the activity of HSUZ-4 zeolite in the dimethyl ether carbonylation reaction was significantly improved by adjusting the acid distribution. The preferential carbonylation reaction at the T1-O12 site located in 8-MR was revealed for the first time, and it was discovered that promoting crystal growth along the c axis can further enhance the activity of HSUZ-4 zeolite.
Article
Engineering, Chemical
Feng Chen, Xiao-Bo Feng, Li-Yun Zhang, Jing-Ping Zhao, Zi-Meng He, Feng-Jiao Yi, Xiao-Yan Zhao, Jing-Pei Cao
Summary: This study aims to tailor the distribution of Bronsted acid sites in the 8-membered ring channels of H-Mordenite (HMOR) by adding aniline or p-phenylenediamine as additives to the sol-gel. The results show a significant increase in the number of Bronsted acid sites in the 8-membered ring channels, while the number of acid sites in the 12-membered ring channels remains relatively unchanged. The synthesized HMOR zeolite exhibits an nearly 2-fold increase in the conversion of dimethyl ether (DME) to methyl acetate in the carbonylation reaction. This finding not only provides a facile strategy for regulating the acid distribution in different channels of zeolites, but also presents a promising catalyst candidate for the critical intermediate step of ethanol synthesis from syngas.
CHEMICAL ENGINEERING SCIENCE
(2022)
Article
Chemistry, Multidisciplinary
Wei Chen, Guangchao Li, Xianfeng Yi, Sarah J. Day, Karolina A. Tarach, Zhiqiang Liu, Shang-Bin Liu, Shik Chi Edman Tsang, Kinga Gora-Marek, Anmin Zheng
Summary: This study investigates the crucial role of ketene in zeolite catalysis and emphasizes the significant influence of confinement effect on the formation and transformation of active intermediates. Different reaction pathways inside MOR framework lead to distinct outcomes, advancing the understanding of zeolite catalysis mechanism.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2021)
Article
Acoustics
L. Kuterasinski, U. Filek, M. Gackowski, M. Zimowska, M. Ruggiero-Mikolajczyk, P. J. Jodlowski
Summary: The ultrasonic-assisted desilication technique was shown to be an attractive and efficient method for preparing hierarchical zeolites with MFI structure type, which exhibited high selectivity and catalytic activity for the dehydration of ethanol. The use of ultrasounds during desilication procedure led to higher extraction of silicon and aluminum, resulting in elevated mesoporosity and enhanced catalytic properties in the prepared samples.
ULTRASONICS SONOCHEMISTRY
(2021)
Article
Chemistry, Applied
Stefanie C. M. Mizuno, Siriwan Dulnee, Tassia C. P. Pereira, Ricardo J. Passini, Ernesto A. Urquieta-Gonzalez, Jean Marcel R. Gallo, Joao B. O. Santos, Jose M. C. Bueno
Summary: This study investigates the influences of Cu content, Si/Al ratio, and sample preparation method on the active Cu species in mordenite (MOR). The XANES spectra indicate that isolated Cu+ species were formed after interaction with CH4 and were re-oxidized under a flow of water steam, showing the impact of different Cu species on CH4 oxidation.
Article
Chemistry, Multidisciplinary
Amy J. Knorpp, Ana B. Pinar, Christian Baerlocher, Lynne B. McCusker, Nicola Casati, Mark A. Newton, Stefano Checchia, Jordan Meyet, Dennis Palagin, Jeroen A. van Bokhoven
Summary: The research investigates the conversion of methane to methanol using copper-exchanged zeolites, with current productivity levels still too low. By understanding the nature of the active site, more effective catalysts could be designed for this conversion process.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Analytical
Yujie Peng, Leilei Dai, Anqi Dai, Qiuhao Wu, Rongge Zou, Yuhuan Liu, Roger Ruan, Yunpu Wang
Summary: The quick and harmless disposal of PVC-containing municipal solid wastes and their conversion into valuable resources is an urgent issue. This study found that different catalysts with varying pore structures and acid site concentrations have different catalytic effects on the cracking mechanism of PVC. MCM-41 showed higher catalytic activity in PVC polymer degradation.
JOURNAL OF ANALYTICAL AND APPLIED PYROLYSIS
(2022)
Article
Chemistry, Physical
Jihyeon Lee, Ji Hui Seo, Chinh Nguyen-Huy, Euiseob Yang, Jun Gyeong Lee, Hojeong Lee, Eun Jeong Jang, Ja Hun Kwak, Jun Hee Lee, Hosik Lee, Kwangjin An
Summary: Combining theoretical calculations with empirical analyses, it was found that Cu2O is the major active species promoting the high activity of furfural hydrogenation.
APPLIED CATALYSIS B-ENVIRONMENTAL
(2021)
Article
Chemistry, Multidisciplinary
Zhiping Xiong, Guodong Qi, Ensheng Zhan, Yueying Chu, Jun Xu, Jiake Wei, Na Ta, Aijing Hao, Yan Zhou, Feng Deng, Wenjie Shen
Summary: Mordenite is an effective catalyst for the carbonylation of dimethyl ether to methyl acetate, and the activity is determined by the number of Bronsted acid sites in its 8-member-ring pore. Experimental evidence shows that the specific activity of the T3 site is 4 times higher than that of the T4 site at 473 K. This study provides insights into the unique reaction mechanism at the T3 site.
Article
Chemistry, Multidisciplinary
Dexin Zhang, Kang Li, Junli Chen, Changyu Sun, Zhi Li, Jie Lei, Qinlan Ma, Pan Zhang, Yong Liu, Lin Yang
Summary: Hierarchical ZSM-35 materials with superior catalytic activity and stability were prepared through post-treatment with NH4F etching. Moderate treatment conditions retained the intrinsic structure and acidity of zeolites, leading to better catalytic performance and stability, while severe etching disrupted the crystalline framework and decreased catalytic performance.
Article
Energy & Fuels
Chengda Li, Yueli Wen, Bin Wang, Maohong Fan, Wenlong Liu, Zheng Cui, Wei Huang
Summary: Activation and desorption of hydrogen in toluene methyl is the rate-limiting step for side-chain alkylation of toluene with methanol. In this study, two dehydrogenation strategies were employed to enhance catalytic performance by introducing Cu as a dehydrogenation component in PAl-NaX catalyst and adjusting the acid-base properties through varying NaOH loading. The relationship between the percentage of acid-base sites, low valence Cu species, and catalytic performance was investigated using various characterization techniques and ternary regression analysis. The results showed that Cu, especially low valence Cu species, promoted the selectivity of side-chain alkylation products to some extent, but base sites played a more critical role in enhancing selectivity.
Article
Chemistry, Physical
Junya Ohyama, Yuka Tsuchimura, Airi Hirayama, Hiroki Iwai, Hiroshi Yoshida, Masato Machida, Shun Nishimura, Kazuo Kato, Keisuke Takahashi
Summary: The catalytic performance of Cu zeolites for the direct conversion of methane to methanol was investigated. The reduction rate of Cu-CHA was found to be highly correlated with catalytic activity. The reduction of Cu2+ is associated with the activation of C-H bonds in CH4, which is the rate-determining step for the reaction. The local structure of Cu-CHA affects selectivity, turnover frequency, and Cu2+ reduction rate.
Article
Chemistry, Multidisciplinary
Ning Wang, Xinglong Dong, Lingmei Liu, Dali Cai, Qingpeng Cheng, Jianjian Wang, Yilin Hou, Abdul-Hamid Emwas, Jorge Gascon, Yu Han
Summary: The crystal size of HZSM-5 determines the form and location of MoCx species; MoCx sites are preferentially deactivated on nano-sized HZSM-5; Properly protecting MoCx particles can enhance their activity.
CELL REPORTS PHYSICAL SCIENCE
(2021)
Article
Chemistry, Applied
Rajesh Bera, Chandan Adhikary
Summary: The zeolite immobilized hybrid catalyst prepared by immobilizing Cu(II)-bipyridine complex onto NaY zeolite exhibited excellent catalytic potency and product selectivity, showing true heterogeneous nature after several cycles of use.
JOURNAL OF POROUS MATERIALS
(2021)
Article
Chemistry, Multidisciplinary
Paul Henri Alle, Patricia Garcia-Munoz, Kopoin Adouby, Nicolas Keller, Didier Robert
Summary: Household wastewaters contain microplastics and nanoplastics that are not filtered by current wastewater treatment plants, requiring advanced removal technologies such as photocatalysis. Degradation of PMMA and PS nanoparticles using TiO2-P25/beta-SiC foams under UV-A radiation showed that lower pH and flow rate led to faster degradation, with 140-nm PS degrading quicker than 508-nm PS.
ENVIRONMENTAL CHEMISTRY LETTERS
(2021)
Article
Chemistry, Multidisciplinary
Hamza El Marouazi, Pablo Jimenez-Calvo, Edouard Breniaux, Christophe Colbeau-Justin, Izabela Janowska, Valerie Keller
Summary: The study investigated the characteristics of few layer graphene/TiO2 photocatalytic composites with loadings ranging from 0.5 to 11 wt % and their impact on hydrogen production from methanol. It was found that the composites with 0.5 and 1.0 wt % FLG/TiO2 exhibited the best activity.
ACS SUSTAINABLE CHEMISTRY & ENGINEERING
(2021)
Article
Chemistry, Physical
Nicolas Keller, Javier Ivanez, James Highfield, Agnieszka M. Ruppert
Summary: This review critically evaluates the advances in photo-/thermal synergies in catalysis, focusing on the impact of dual-mode excitation on key processes in future solar-biorefineries. It also discusses the classification of possible co-excitation synergies and the inclusion of pan-spectral absorbers in catalyst design towards process intensification.
APPLIED CATALYSIS B-ENVIRONMENTAL
(2021)
Article
Chemistry, Applied
Javier Ivanez, Patricia Garcia-Munoz, Agnieszka M. Ruppert, Nicolas Keller
Summary: Dual mode excitation of catalysts using both photonic and thermal activation has gained increasing interest in recent years due to its potential benefits in enhancing catalytic reactions. The combination of photon and thermal excitation can increase reaction efficiency and selectivity, especially at high irradiance levels. This new approach allows reactions to be driven at lower temperatures and improves the selectivity for hydrogen production.
Article
Chemistry, Physical
Armelle Sengele, Didier Robert, Nicolas Keller, Valerie Keller
Summary: This study investigated the efficiency of Ta and Sn doped TiO2 photocatalysts for the elimination of diethyl sulfide (DES) and compared their photo-oxidation efficiency with TiO2-P25. Results showed that Sn-doped TiO2 exhibited higher initial activity but deactivated faster, while Ta-doped TiO2 had slower deactivation rate. The adsorption properties of the beta-SiC foams significantly influenced the activity of the catalysts.
Article
Chemistry, Physical
Ana Amoros-Perez, Maria Angeles Lillo-Rodenas, Maria del Carmen Roman-Martinez, Patricia Garcia-Munoz, Nicolas Keller
Summary: TiO2 and TiO2-activated carbon photocatalysts were prepared and tested for the removal of diuron from water. The carbon content was found to influence the removal efficiency, with the sample containing the highest carbon content showing the highest removal rate.
Article
Chemistry, Physical
Patricia Garcia-Munoz, Fernando Fresno, Javier Ivanez, Nicolas Keller
Summary: This study evaluates the control exerted on ruthenium nanoparticles supported on TiO2 by a photoassisted method, showing that the photodeposition rate and Ru-0/Ru delta+ ratio play crucial roles in photocatalytic activity. Nanoparticles synthesized under different irradiance conditions exhibit varied sizes and oxidation states, influencing the overall performance in formic acid oxidation.
Article
Green & Sustainable Science & Technology
Pablo Jimenez-Calvo, Valerie Caps, Valerie Keller
Summary: Solar energy and photocatalysis are key players in the energy transition, with hydrogen emerging as an ideal solar fuel due to its simplicity in the water-splitting reaction. However, the challenge lies in finding a single catalyst with sufficient conversion efficiency. The development of multi-phase composites, plasmonic Schottky junctions, and Z-scheme heterojunctions are promising approaches to enhancing hydrogen production.
RENEWABLE & SUSTAINABLE ENERGY REVIEWS
(2021)
Article
Chemistry, Physical
Daniel Glass, Raul Quesada-Cabrera, Steven Bardey, Premrudee Promdet, Riccardo Sapienza, Valerie Keller, Stefan A. Maier, Valerie Caps, Ivan P. Parkin, Emiliano Cortes
Summary: Research shows that in photocatalytic processes, the lifetime of in situ generated oxygen vacancies (VO) plays a more important role in catalysis than concentration, with longer-lived VO significantly enhancing photocatalytic activity. Enhanced photocatalytic efficiency is associated with optimal VO concentrations that encourage carrier transport while avoiding charge carrier trapping.
ACS ENERGY LETTERS
(2021)
Article
Chemistry, Applied
Patricia Garcia-Munoz, Fernando Fresno, Christophe Lefevre, Didier Robert, Nicolas Keller
Summary: In the search for more efficient low-temperature catalysts, the substitution of La3+ by Ti3+ cations in LaFeO3 orthoferrites was found to enhance the UV-A light driven activity. La1_xTixFeO3 catalysts were synthesized using a modified Pechini sol-gel route with a solid source of titanium. The amorphous content of the TiO2 precursor played a crucial role in the substitution process. The substitution was proposed to occur via solid-solid diffusion between TiO2 and amorphous LaFeO3 during thermal treatment.
Article
Chemistry, Applied
Patricia Garcia-Munoz, Javier Ivanez, Victor A. de la Pena O'Shea, Nicolas Keller, Fernando Fresno
Summary: In this study, the feasibility of using alveolar open-cell beta-SiC foams as a catalyst support for solar hydrogen production was explored. Pt and Ru nanoparticles were obtained through photoassisted synthesis and tested for gas-phase hydrogen production from water-ethanol mixtures. The foam-supported photocatalysts, including Pt/TiO2 and Ru/TiO2, showed activity in solar photocatalytic reactions, with Pt/TiO2 being the most active. The foam pore size had little influence on hydrogen outcome, and a UV-to-hydrogen conversion efficiency of 14% (equivalent to 0.49% solar-to-hydrogen) was achieved under the best conditions, with a photonic efficiency higher than 30%.
Article
Energy & Fuels
Emilia Soszka, Marcin Jedrzejczyk, Nicolas Keller, Agnieszka M. Ruppert
Summary: The sustainable production of environmentally-friendly alternative fuels is important for future biorefinery schemes. In this study, bimetallic Ni-Co/gamma-Al2O3 catalysts were used to efficiently produce 2-MTHF, and the key factors affecting the yield and selectivity were identified.
Review
Chemistry, Multidisciplinary
Patricia Garcia-Munoz, Laura Valenzuela, Deborah Wegstein, Tobias Schanz, Girlie Eunice Lopez, Agnieszka M. Ruppert, Hynd Remita, Jonathan Z. Bloh, Nicolas Keller
Summary: Hydrogen peroxide is a powerful and green oxidant that is used in various applications. The article reviews the recent development of photocatalytic synthesis of hydrogen peroxide, discussing different mechanisms, kinetic models, and key reaction parameters. A wide range of photocatalytic materials, including titania-based and graphitic carbon nitride-based systems, are reviewed. Strategies for enhancing the performance of solar-driven photocatalysts and the search for new photocatalytic materials are discussed. The promise of in situ photocatalytic synthesis of hydrogen peroxide, its coupling with enzymes, and the synthesis of other technical peroxides are also described.
TOPICS IN CURRENT CHEMISTRY
(2023)
Article
Engineering, Environmental
Patricia Garcia-Munoz, Paul Henri Alle, Calogera Bertoloni, Alvaro Torres, Maria Ulagares de la Orden, Joaquin Martinez Urreaga, Marie-Antoinette Dziurla, Fernando Fresno, Didier Robert, Nicolas Keller
Summary: The study investigates the reliability and quantifiability of a wide range of characterization and analytical tools in monitoring the mineralization process of polystyrene nanoparticles. The immobilized reaction mode is found to be superior to the slurry mode due to the absence of restrictive nanoparticulate photocatalyst. Direct imaging and light-scattering characterization provide incomplete and irrelevant data due to the change in polystyrene substrate morphology. TOC analysis remains the most suitable and reliable technique for monitoring and quantifying the mineralization process of polystyrene nanoparticles.
JOURNAL OF ENVIRONMENTAL CHEMICAL ENGINEERING
(2022)
Article
Chemistry, Physical
Emilia Soszka, Marcin Jedrzejczyk, Christophe Lefevre, Dris Ihiawakrim, Nicolas Keller, Agnieszka M. Ruppert
Summary: This study reports on the efficient synthesis of 2-methyltetrahydrofuran using earth-abundant non-noble metal cobalt catalysts supported on titanium dioxide. The size of cobalt particles and metal-support interaction were found to significantly influence the catalyst's performance, in addition to the catalyst acidity.
CATALYSIS SCIENCE & TECHNOLOGY
(2022)