Article
Chemistry, Physical
Charlotte Croise, Remy Pointecouteau, Joudia Akil, Alain Demourgues, Nicolas Bion, Xavier Courtois, Fabien Can
Summary: The study found that partial substitution of zirconium for praseodymium in a ceria-zirconia support can enhance the support reducibility, but impregnation of niobium and tungsten inhibits the redox behaviors. Additionally, niobium and tungsten provide acidic sites while praseodymium inhibits ammonia storage and decreases deNO(x) performances. The various redox and acidic behaviors observed in the studied materials demonstrate a strong competition between NOx SCR and NH3 oxidation pathways.
APPLIED CATALYSIS B-ENVIRONMENTAL
(2021)
Article
Chemistry, Multidisciplinary
Kyungseok Lee, Byungchul Choi
Summary: A combined Ag/Al2O3 and Pd/Al2O3 catalyst was found to be effective for the selective catalytic reduction of NOx by H-2-assisted C3H6. The sequential arrangement of 1 wt% Ag/Al2O3 followed by 1Pd/Al2O3 enabled the reduction of NOx, C3H6, CO, and H-2 over wide reaction temperatures, with negligible formation of by-products.
JOURNAL OF INDUSTRIAL AND ENGINEERING CHEMISTRY
(2021)
Article
Chemistry, Physical
Han Sun, Fei Han, Lu Sun, Shinya Mine, Takashi Toyao, Yunpeng Liu, Zhonghua Wu, Masaaki Kitano, Masaya Matsuoka, Weiwei Liu, Yongqiang Dai, Meiqing Shen, Haijun Chen
Summary: Selective catalytic reduction by methanol (Methanol-SCR) is a promising technology for treating exhaust with high concentration of sulfur. A new catalyst of nano-bismuth oxide implanted FER zeolites (Bi-FER) has been successfully synthesized, showing a lower optimum reaction temperature compared to existing technology. The reactivity of methyl groups generated on Brønsted acid sites neighboring with nano-bismuth oxide has been found to be highly effective for NOx removal. Therefore, a strategy of methanol activation to produce reactive methyl groups has been proposed for improving Methanol-SCR catalysts.
APPLIED CATALYSIS B-ENVIRONMENTAL
(2022)
Article
Energy & Fuels
Chaolu Wen, Yanxia Guo, Kezhou Yan, Huirong Zhang
Summary: The production of spent honeycomb V2O5-WO3/TiO2 catalysts has caused serious environmental hazards. This study focused on the changes of typically spent catalysts from pulverized coal (PC) and circulating fluidized bed (CFB) boiler deNOx systems, including morphologies, pore structure, chemical composition, carrier, and active components properties. The major deactivation factors were pore blockage caused by fly ash and sulfur deposition, with CFB catalysts being more easily deactivated due to severe pore structure loss. The transformation of anatase to rutile TiO2 and the shift in valence state of V were major contributors to irreversible deactivation. This research provides valuable insights into the deactivation mechanism and potential recycling of spent catalysts.
Article
Chemistry, Applied
Yang Zhang, Chenghang Zheng, Shaojun Liu, Weihong Wu, Zhen Du, Min Yan, Wentao Zhu, Yue Zhu, Xiang Gao
Summary: The study found that catalysts in coal-fired power plants gradually lose effectiveness over their lifespan, mainly due to a decrease in active ingredients, metal deposition in flue gas, and a reduction in catalyst surface area.
FUEL PROCESSING TECHNOLOGY
(2021)
Article
Chemistry, Physical
Hiroe Kubota, Takashi Toyao, Zen Maeno, Yusuke Inomata, Toru Murayama, Naoto Nakazawa, Satoshi Inagaki, Yoshihiro Kubota, Ken-ichi Shimizu
Summary: In this study, the researchers investigated the reduction/oxidation half-cycles of the selective catalytic reduction of NO with NH3 at 200 degrees C using in situ and operando spectroscopies. They proposed a general mechanism that is applicable to both V and Cu catalysts, where N-2 and H2O are formed during the reduction half-cycle and the regenerated V(V) or Cu(II) sites react with surface H+ to produce H2O during the oxidation half-cycle. The results provide comprehensive evidence of the general mechanism of NH3-SCR.
Article
Chemistry, Physical
Valentina Rizzotto, Stefan Bajic, Dario Formenti, Xiaochao Wu, Silke Sauerbeck, Jonas Werner, Thomas E. Weirich, Tobias Janke, Peter Mauermann, Stefan Pischinger, Regina Palkovits, Ulrich Simon
Summary: Selective catalytic reduction (SCR) by NH3 catalysts remains essential for exhaust gas purification, particularly in heavy-duty diesel engines, despite the growing trend towards electrification of powertrains. The synthesis scale of Cu-exchanged chabazite catalysts for SCR was found to influence their catalytic performance, especially in NH3 oxidation.
Article
Chemistry, Multidisciplinary
Fengyuan Liu, Junqi Li, Chaoyi Chen, Deyang Ning, Jian Yang, Zhiyao Chu, Xisong Mao, Yuanpei Lan
Summary: A novel tactic was employed to evaluate the low-temperature NH3-SCR NOx removal property of manganese oxides in various valence states. It was found that different valence states of manganese oxides exhibited varying activities and NH3 adsorption capacities at different temperatures, significantly impacting SCR activity.
RESEARCH ON CHEMICAL INTERMEDIATES
(2022)
Article
Chemistry, Physical
Fei Han, Han Sun, Zhenchao Zhao, Yaxin Xu, Hong Dong, Weiwei Liu, Lu Sun, Zhili Wang, Guangjin Hou, Masaaki Kitano, Wei Li, Meiqing Shen, Haijun Chen
Summary: In this study, an environmentally friendly deNO(x) method using methanol as a reductant and pure H-FER zeolite as the catalyst was proposed. The metal-free zeolite showed nearly 4 times higher activity compared to commonly used precious metal catalysts. It exhibited comparable deNO(x) efficiency with state-of-the-art NH3-SCR on vanadium-based catalysts, along with good stability and potential for industrial application.
Article
Chemistry, Physical
Yu Fu, Guangzhi He, Yulong Shan, Jinpeng Du, Hong He
Summary: This study investigates the mechanism of NH3-SCR reaction over Cu-SSZ-13 catalysts using density functional theory calculations. The results show that the activation of NO at Cu sites and the participation of water reduce the energy barrier for the regeneration of active sites, while the coupling effect of Bronsted acid and Cu-OH sites shortens the reaction pathway and lowers the energy barrier for the decomposition of key intermediates.
CATALYSIS SCIENCE & TECHNOLOGY
(2022)
Article
Chemistry, Multidisciplinary
Kyungseok Lee, Byungchul Choi, Cheolho Kim, Chunbeom Lee, Kwangchul Oh
Summary: The combination of Ag/Al2O3 and CuSn/ZSM-5 showed superior catalytic performance in reducing NOx and oxidizing C3H6 at lower temperatures. Sequential arrangement of 1Ag/Al2O3 + 2Cu1Sn/ZSM-5 was found to be the best catalytic configuration for simultaneous reduction of NOx, C3H6, and H-2 over a wide temperature range. The reduced NOx was mostly converted to N-2 with minimal generation of N2O, NH3, and HCNO.
JOURNAL OF INDUSTRIAL AND ENGINEERING CHEMISTRY
(2021)
Article
Chemistry, Physical
Kaiwei Qin, Shujun Ming, Zhen Chen, Shoute Zhang, Ying Meng, Qin Wu, Ce Bian, Qian Liu, Lei Guo, Dan Li, Lei Pang, Tao Li
Summary: The addition of Nd in Cu-SAPO-18 catalyst effectively enhances the catalytic performance, especially in the conversion of NOx. The modified catalyst exhibits larger specific surface area and uniform pore size distribution, mitigating dealumination progress and aggregation of copper species. Moreover, the incorporation of Nd enhances the redox property and stabilizes the surface acid sites of the catalyst.
Article
Engineering, Chemical
Aldo Lanza, Nicola Usberti, Pio Forzatti, Alessandra Beretta
Summary: The deposition of ashes over the catalysts was identified as the major cause of performance loss in the selective catalytic reduction (SCR) reactors. Scratching the surface layer of the aged catalysts resulted in a significant recovery of the DeNO(x) removal efficiency.
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
(2021)
Article
Chemistry, Physical
Asghar Mohammadi, Corsin Praty, Ali Farzi, Hamid Soleimanzadeh, Sabine Schwarz, Michael Stoger-Pollach, Johannes Bernardi, Simon Penner, Aligholi Niaei
Summary: This study investigates the effect of cerium and tungsten addition on the deNO(x) activity of V2O5/TiO2 catalysts in the NH3-SCR reaction. The addition of CeO2 and WO3 improves the operation temperature range and N-2 selectivity of the catalysts under dry and wet conditions. The thermal deactivation resistance of the catalysts is enhanced with increasing amount of WO3. Water decreases the overall catalytic activity at low temperatures but prevents the formation of N2O at high temperatures. CeO2 reduces the reducibility of the catalysts, while W increases the H-2 uptake.
Article
Chemistry, Physical
Xu Wu, Lili Liu, Jiangning Liu, Benhui Hou, Yali Du, Xianmei Xie
Summary: A series of Ni and Mn based single/double metal oxides were prepared using a facile glycine combustion method and tested for low temperature selective catalytic reduction of NO with NH3. The NiMn-400 sample exhibited outstanding catalytic performance with high NOx conversion, N2 selectivity, and SO2 resistance. The enhanced activity of NiMn-400 catalyst could be attributed to the coordination of Ni and Mn, higher Mn4+/Mnn+ ratio, suitable acid sites, and redox capacity.
APPLIED CATALYSIS A-GENERAL
(2021)
Article
Chemistry, Physical
A. V. Gonzalez, J. Rostrup-Nielsen, K. Engvall, L. J. Pettersson
APPLIED CATALYSIS A-GENERAL
(2015)
Article
Chemistry, Physical
Moa Z. Granlund, Kjell Jansson, Marita Nilsson, Jazaer Dawody, Lars J. Pettersson
APPLIED CATALYSIS B-ENVIRONMENTAL
(2015)
Article
Chemistry, Physical
Fredrik Gunnarsson, Moa Z. Granlund, Mattias Englund, Jazaer Dawody, Lars J. Pettersson, Hanna Harelind
APPLIED CATALYSIS B-ENVIRONMENTAL
(2015)
Article
Chemistry, Physical
A. Scarabello, D. Dalle Nogare, P. Canu, R. Lanza
APPLIED CATALYSIS B-ENVIRONMENTAL
(2015)
Article
Chemistry, Applied
A. Bernardini, N. Gemo, P. Biasi, P. Canu, J. P. Mikkola, T. Salmi, R. Lanza
Article
Energy & Fuels
Pouya H. Moud, Klas J. Andersson, Roberto Lanza, Jan B. C. Pettersson, Klas Engvall
Article
Chemistry, Applied
Moa Z. Granlund, Sabine Zacherl, Lars J. Pettersson
TOPICS IN CATALYSIS
(2015)
Article
Chemistry, Physical
Sandra Dahlin, Marita Nilsson, Daniel Backstrom, Susanna Liljegren Bergman, Emelie Bengtsson, Steven L. Bernasek, Lars J. Pettersson
APPLIED CATALYSIS B-ENVIRONMENTAL
(2016)
Article
Chemistry, Physical
Moa Z. Granlund, Kjell Jansson, Marita Nilsson, Jazaer Dawody, Lars J. Pettersson
APPLIED CATALYSIS B-ENVIRONMENTAL
(2014)
Article
Chemistry, Physical
Moa Z. Granlund, Oliver Goerke, Peter Pfeifer, Lars J. Pettersson
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2014)
Article
Chemistry, Physical
Roberto Lanza, Marco Bersani, Luca Conte, Alessandro Martucci, Paolo Canu, Massimo Guglielmi, Giovanni Mattei, Valentina Bello, Massimo Centazzo, Renzo Rosei
JOURNAL OF PHYSICAL CHEMISTRY C
(2014)
Article
Chemistry, Physical
Susanna L. Bergman, Jonas Granestrand, Shibo Xi, Yonghua Du, Yu Tang, Chunhua Tang, Liene Kienkas, Lars J. Pettersson, Steven L. Bernasek
JOURNAL OF PHYSICAL CHEMISTRY C
(2020)
Article
Chemistry, Physical
Vitaly Mesilov, Yang Xiao, Sandra Dahlin, Susanna L. Bergman, Lars J. Pettersson, Steven L. Bernasek
Summary: A combination of first-principles thermodynamics and density functional theory was used to predict sulfur-poisoned monomeric Cu/Fe species formed in the SSZ-13 catalyst framework. Differences in fresh and sulfur-poisoned species were found for Cu- and Fe-SSZ-13 catalysts containing different amounts of Al in 6-membered or 8-membered rings. The impact of ammonia concentration on Cu- and Fe-speciation was also investigated.
JOURNAL OF PHYSICAL CHEMISTRY C
(2021)
Article
Chemistry, Physical
Vitaly Mesilov, Sandra Dahlin, Susanna L. Bergman, Shibo Xi, Johanna Englund, Henrik Malm, Lars J. Pettersson, Steven L. Bernasek
Summary: Biodiesel contaminants can affect the Cu speciation of Cu-SSZ-13 catalyst, resulting in its deactivation. In this study, in situ XAFS scanning was applied to analyze Cu speciation in Cu-SSZ-13 catalysts aged with pure and contaminated biodiesel fuels. The presence of phosphorus in biofuels was found to be responsible for the formation of Cu clusters during catalyst aging.
JOURNAL OF PHYSICAL CHEMISTRY C
(2022)
Article
Chemistry, Physical
Vitaly Mesilov, Lorngdy Pon, Sandra Dahlin, Susanna L. Bergman, Lars J. Pettersson, Steven L. Bernasek
Summary: In this study, first-principles thermodynamics and density functional theory were used to predict the formation of monomeric palladium, platinum, and ruthenium species in noble metal-exchanged small-pore molecular sieves. The results showed that the binding energy of NO adsorbed on these metal ions is strongly influenced by the choice of exchange-correlation functional. The study also revealed that the adsorption of NO is stronger in 1Al sites compared to 2Al sites.
JOURNAL OF PHYSICAL CHEMISTRY C
(2022)
Article
Chemistry, Applied
Qingyuan Zheng, Jack H. Williams, Scott Elgersma, Mick D. Mantle, Andrew J. Sederman, G. Leendert Bezemer, Constant M. Guedon, Lynn F. Gladden
Summary: In this study, a pilot-scale fixed-bed reactor compatible with NMR/MRI was developed for Fischer-Tropsch synthesis. Multiple magnetic resonance techniques were applied to quantitatively characterize different product species within catalyst pellets, providing valuable information for catalyst and reactor optimization.
Article
Chemistry, Applied
Lisa Ramisch, Sebastian Pfaff, Sabrina M. Gericke, Edvin Lundgren, Johan Zetterberg
Summary: We present a combination of optical operando techniques that allow simultaneous measurement of adsorbed species on catalyst surfaces, monitoring of surface oxide formation, and imaging of the gas phase above the catalyst surface. The experimental setup was validated by studying CO oxidation on Pd(100) at different pressures, revealing the effects of pressure on the heterogeneous catalytic reaction.
Article
Chemistry, Applied
Marta Paniagua, Gabriel Morales, Juan A. Melero, Daniel Garcia-Salgado
Summary: The influence of common impurities in levulinic acid on the catalytic performance of different acid catalysts for bio-jet fuel production was studied. It was found that furfural had the greatest detrimental effect on catalyst performance, while propyl-sulfonic acid-modified SBA-15 and sulfonic acid resin Amberlyst-70 showed good regeneration ability.
Article
Chemistry, Applied
Jesus Tapiador, Pedro Leo, Guillermo Calleja, Gisela Orcajo
Summary: This study presents a new MOF material, Zn-URJC-13, with acid and basic sites, permanent porosity, and high affinity to CO2 molecules. The Zn-URJC-13 catalyst exhibits efficient performance in CO2 cycloaddition reactions and can be reused multiple times.
Article
Chemistry, Applied
Dan Zhao, Vita A. Kondratenko, Dmitry E. Doronkin, Shanlei Han, Jan-Dierk Grunwaldt, Uwe Rodemerck, David Linke, Evgenii V. Kondratenko
Summary: This study demonstrates the potential of cheap and commercially available Zr or Ti-based supports and ZnO to serve as active and selective catalysts for propane dehydrogenation (PDH). The catalytically active species formed in situ under PDH conditions consist of isolated ZnOx. ZnOx on the surface of LaZrOx shows the highest rate of propene formation.
Article
Chemistry, Applied
Hanbyeol Kim, Jung Rae Kim, Young-Kwon Park, Jeong-Myeong Ha, Jungho Jae
Summary: In this study, metal phosphates were used as catalysts for biomass conversion to produce sustainable aromatics through DielsAlder cycloaddition reactions. The effects of synthesis method, activation method, and P/Ti molar ratio on the structure and acid properties of titanium phosphate catalysts were systematically studied. The mesoporous titanium phosphate catalyst synthesized by hydrothermal method at 180℃ for 12 h followed by ethanol refluxing at 60℃ for 24 h at a molar P/Ti ratio of 1 showed the highest surface area and acid site density.
Article
Chemistry, Applied
Yasin Khani, Sumin Pyo, Kwang-Eun Jeong, Chul-Ung Kim, Moonis Ali Khan, Byong-Hun Jeon, Kun-Yi Andrew Lin, Siyoung Q. Choi, Young-Kwon Park
Summary: A protonated form of Zeolite Socony Mobil-5 (H-ZSM-5) catalyst was synthesized through a hydrothermal method using different sources of silica. The effect of loading the catalyst with yttrium, samarium, and gadolinium on the acidic properties was investigated. Among the metal-loaded catalysts, the Sm/LHZ catalyst showed the best performance in the methanol to propylene conversion due to its high amount of weak and intermediate acid sites, while the Gd-LHZ catalyst increased the selectivity towards ethane and propane.
Article
Chemistry, Applied
Michael Franc, Ivana Cisarova, Jan Vesely
Summary: The present study investigates an enantioselective cyclization of enals with imidazolone derivatives catalyzed by a combination of achiral Pd(0) complex and chiral secondary amine. Corresponding spirocyclic imidazolones were produced in high yields with moderate diastereoselectivity and excellent enantioselectivity. The developed co-operative catalytic methodology provides a highly substituted spirocyclic scaffold with four stereogenic centers under mild conditions.
Article
Chemistry, Applied
Mauro Alvarez, Jennifer Cueto, David P. Serrano, Pablo Marin, Salvador Ordonez
Summary: This study focuses on improving the formulation and preparation methods of catalysts for the production of dimethyl carbonate. By using suitable catalyst preparation methods and copper salt precursors, the researchers successfully produced catalysts with optimal performance for dimethyl carbonate formation.
Article
Chemistry, Applied
Claudia J. Keijzer, Luc C. J. Smulders, Dennie Wezendonk, Jan Willem de Rijk, Petra E. de Jongh
Summary: This study investigates the catalytic behavior of alpha-alumina supported silver catalysts in the presence of chloride. It is found that the particle size of silver can affect the selectivity of the catalyst, but different strategies lead to different results. In this size range, the selectivity of ethylene oxide is correlated to the Ag : Al2O3 surface ratio.
Article
Chemistry, Applied
Takeshi Aihara, Wataru Aoki, Michikazu Hara, Keigo Kamata
Summary: The development of acid-base bifunctional catalysts is important for promoting specific chemical transformations. In this study, Ti-based perovskite oxides were synthesized and used as catalysts for two C-C bond-forming reactions (cyanosilylation and Knoevenagel condensation). The highly pure SrTiO3 nanoparticles with a high specific surface area exhibited the highest catalytic performance, and could be easily recovered and reused.
Article
Chemistry, Applied
Olga Gorlova, Petra Pribylova, Eliska Vyskocilova, Katerina Peroutkova, Jan Kohout, Iva Paterova
Summary: This study investigates the Baeyer-Villiger oxidation of beta-cyclocitral using tin-modified mixed oxides as catalysts. The optimal reaction conditions and the effects of various factors on the reaction course and selectivity were determined. The results show that tin-modified mixed oxides exhibit high activity and selectivity in the oxidation reaction.
Article
Chemistry, Applied
M. I. Avila, M. M. Alonso-Doncel, L. Briones, G. Gomez-Pozuelo, J. M. Escola, D. P. Serrano, A. Peral, J. A. Botas
Summary: The catalytic fast pyrolysis of lignin using ion-exchanged zeolite catalysts showed significant improvements in bio-oil quality and the production of aromatic hydrocarbons and oxygenated compounds.
Article
Chemistry, Applied
Enrico Catizzone, Giorgia Ferrarelli, Paolo Bruno, Girolamo Giordano, Massimo Migliori
Summary: The acid-catalysed alcohol conversion reaction is a promising route for de-fossilization strategies. Research on pure alcohol conversion and simultaneous dehydration of mixed alcohols have shown different product compositions, with the type and distribution of acid sites affecting the reaction mechanism.
Article
Chemistry, Applied
Alireza Ranjbari, Juho Kim, Jihee Yu, Jiyun Kim, Mireu Park, Nayoung Kim, Kristof Demeestere, Philippe M. Heynderickx
Summary: This study investigated a novel kinetic model for the adsorption and photocatalytic degradation of methyl orange using commercial ZnO and reduced ZnO photocatalysts. The results provided new insights into the interaction of catalysts with molecules of different charges and compared with a previous study on methylene blue. The presence of oxygen vacancies in ZnO and their effects on adsorption and photocatalytic degradation were analyzed, and the photocatalytic degradation rate of reduced ZnO was found to increase significantly.
