Article
Chemistry, Physical
Mingyu Jin, Myungwon Oh, Minkee Choi
Summary: This study synthesized a hierarchical BEA zeolite with trimodal porosity and found that it exhibited remarkable catalytic performance and deactivation resistance in the isobutane/butene alkylation reaction, reducing the operating costs of the reaction.
Article
Chemistry, Physical
Mingyu Jin, Myungwon Oh, Minkee Choi
Summary: This study investigates the effect of molecular transport on selectivity and deactivation in isobutane/butene alkylation using different BEA zeolites. The results show that the hierarchical BEA zeolite with trimodal porosity exhibits enhanced selectivity and catalytic lifetime, reducing operating costs.
Article
Engineering, Environmental
Mu He, Muhammad-Faryad Ali, Yue-Qin Song, Xiao-Long Zhou, Jin An Wang, Xin-Yao Nie, Zheng Wang
Summary: This study investigated the coke deactivation behavior of HZSM-5 zeolites with different Si/Al ratios in the n-hexane cracking reaction for 200 hours. The results showed that internal coke formed in the micropores of the zeolite initially and significantly inhibited catalytic activity, while external coke had a minor effect. The deactivation behavior differed between zeolites with low and high Si/Al ratios.
CHEMICAL ENGINEERING JOURNAL
(2023)
Article
Chemistry, Multidisciplinary
Jie Tuo, Yaqi Fan, Yan Wang, Yudan Gong, Chengwei Zhai, Xianchen Gong, Teng Yang, Hao Xu, Jingang Jiang, Yejun Guan, Yanhang Ma, Peng Wu
Summary: Selective conversion of syngas to value-added olefins is a topic of significant research interest. The combination of the pentasil zeolite Al-IDM-1 with ZnaAlbOx oxide shows high selectivity and ratios, making it a promising catalyst for the production of propylene and butene.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Physical
Marta Diaz, Eva Epelde, Jose Valecillos, Sepideh Izaddoust, Andres T. Aguayo, Javier Bilbao
Summary: The deactivation of HZSM-5 catalysts in 1-butene oligomerization is mainly caused by the confinement of oligomers (soft coke) in the catalyst matrix. Soft coke is removed at 400 degrees C by TPS-N-2, while hard coke is removed by combustion. Two types of hard coke are distinguished, with the fraction located in zeolite micropores being more refractory to combustion.
APPLIED CATALYSIS B-ENVIRONMENTAL
(2021)
Article
Thermodynamics
Bruno J. B. Silva, Lenivaldo V. Sousa, Lais R. A. Sarmento, Ana C. S. Melo, Deidiane S. Silva, Paulo H. L. Quintela, Soraya L. Alencar, Antonio O. S. Silva
Summary: The study found that the micro/mesoporous structures in zeolite catalysts help inhibit the loss of crystallinity and maintain acidity, resulting in better stability and activity during catalyst regeneration. Hierarchical ZSM-23 zeolites showed lower deposited coke amounts and activation energy values for the thermal oxidation process, providing superior performance and lower energy levels for regeneration compared to microporous zeolites.
JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
(2022)
Article
Chemistry, Physical
Omar Abed, Hend Omar Mohamed, Idoia Hita, Vijay Velisoju, Natalia Morlanes, Omar El Tall, Pedro Castano
Summary: This study compares the effects of different catalyst structures on adsorption and catalysis, exploring the roles of pore topology, Ni sites, and acid sites. The results show that acid sites are particularly important during the initial stages of the reaction, and using a continuous reactor alone may lead to misinterpretation. Ni accelerates the reaction and improves the selectivity towards oligomers. Based on the experimental results, the dominant mechanisms over the different catalyst sites and reaction times are discussed.
Article
Chemistry, Physical
Guangyu Zhao, Penghui Yan, Kerryn Procter, Adesoji Adesina, Yonggang Jin, Eric Kennedy, Michael Stockenhuber
Summary: The effect of desilication on the physic-chemical properties of ferrierite zeolite was investigated. The study found that desilication led to changes in the textural properties of the zeolite, resulting in an increase in mesopore area and a greater concentration of terminal Si-OH groups. The catalytic activity for the conversion of methane was also studied, and it was found that Fe-FER catalysts prepared with a moderately alkaline solution showed the highest yield of methanol, dimethyl ether, and formaldehyde.
JOURNAL OF CATALYSIS
(2023)
Article
Thermodynamics
Zuria Tabernilla, Ainara Ateka, Javier Bilbao, Andres T. Aguayo, Eva Epelde
Summary: The ethylene oligomerization into liquid fuels under slightly over atmospheric pressure is a promising way to utilize excess ethylene and intensify fuel production from refinery secondary streams. Experimental runs were conducted in a fixed-bed reactor using a hierarchical porous catalyst, and results showed a high yield of C5+ liquid fuel at temperatures above 325 degrees C. The matrix in the catalyst played a significant role in attenuating deactivation and the cracking of hard coke.
Article
Energy & Fuels
Amir Salar Abdulghaffari, Mohammad Kazemeini
Summary: This research introduces a computational framework to identify the optimal model for catalyst deactivation and coke formation kinetics. The framework leverages the concept of active site loss and demonstrates high accuracy and simplicity. It also transforms deactivated catalyst data into a unified dataset, positively impacting the kinetic study of main reactions.
Article
Chemistry, Physical
Gabriel L. Catuzo, Luiz G. Possato, Maria Eugenia Sad, Cristina Padro, Leandro Martins
Summary: This study investigates the detailed aging of coke in spent H-ZSM-5 zeolites after their use in the gas-phase glycerol dehydration to produce acrolein. The carbonaceous deposits formed rapidly in the pores hampering the accessibility to active sites and the zeolite's catalytic action. The types of coke formed during the reaction and their impact on the zeolite's structure and accessibility to acid sites were also examined.
Article
Chemistry, Physical
Zaizhe Cheng, Shouying Huang, Ying Li, Kai Cai, Yue Wang, Mei-yan Wang, Jing Lv, Xinbin Ma
Summary: The study focuses on dissecting the role of BASs in the 8-MR and B12-MR in deactivation, revealing the contribution of B8-MR to coke formation. Through kinetic studies and various spectroscopic techniques, the predominant deactivation pathway during the early stage of DME carbonylation and the specific roles of BASs, especially in the 8-MR, were identified. This insight into the deactivation mechanism will provide inspiration for the further design and modification of robust zeolite catalysts associated with the carbonylation reaction.
Article
Engineering, Environmental
Karoline L. Hebisch, Pawel A. Chmielniak, Rick Watson, David Leyshon, Barbara Kimmich, Rui Xu, Benjamin Galfond, Carsten Sievers
Summary: This study investigates the effects of temperature and carbon deposition on the catalytic activity of zeolite via high temperature and ambient X-ray powder diffraction. The results show that internal carbon deposits are responsible for structural distortion and counteract thermal contraction, while external coke species drive catalyst deactivation.
CHEMICAL ENGINEERING JOURNAL
(2023)
Article
Chemistry, Applied
Tomas Cordero-Lanzac, Cristina Martinez, Andres T. Aguayo, Pedro Castano, Javier Bilbao, Avelino Corma
Summary: This study investigates the synergies between oxygenates (especially dimethyl ether) and n-pentane at low OX/nC(5) ratios, enhancing n-pentane conversion while reducing catalyst coking rate. The analysis of used catalysts reveals that dimethyl ether exhibits higher reactivity than methanol in forming coke structures.
Article
Chemistry, Physical
Chase N. Taylor, Jagoda Urban-Klaehn, Thuy T. Le, Radoslaw Zaleski, Jeffrey D. Rimer, Kevin L. Gering
Summary: The study investigates the aging characteristics of catalysts using positron annihilation spectroscopy, tracking the evolution of microstructures in zeolite catalysts during deactivation. Results show that as the reaction progresses, zeolite nanopores decrease in size while mesopores increase, indicating a change in defect structure. The technique's sensitivity to different pore structures suggests it may be useful for heterogeneous catalysis studies.
Article
Chemistry, Physical
Hoin Lee, Songhyun Lee, Ryong Ryoo, Minkee Choi
JOURNAL OF CATALYSIS
(2019)
Article
Chemistry, Physical
Kyungho Lee, Mi-Eun Lee, Jae-Kon Kim, Byeongcheol Shin, Minkee Choi
JOURNAL OF CATALYSIS
(2019)
Article
Chemistry, Applied
In Yong Eom, Songhyun Lee, Sung Yeon Hwang, Minkee Choi
MICROPOROUS AND MESOPOROUS MATERIALS
(2020)
Article
Multidisciplinary Sciences
Songhyun Lee, Seung-Jae Shin, Hoyong Baek, Yeonwoo Choi, Kyunglim Hyun, Myungeun Seo, Kyunam Kim, Dong-Yeun Koh, Hyungjun Kim, Minkee Choi
Article
Green & Sustainable Science & Technology
Tae-Hyoung Kim, Kyungho Lee, Baek-Rock Oh, Mi-Eun Lee, Minji Seo, Sheng Li, Jae-Kon Kim, Minkee Choi, Yong Keun Chang
Summary: This study demonstrates an economically beneficial process for coproducing biojet fuel and high-value polyunsaturated fatty acids from Schizochytrium sp. ABC101 microalgae. The separation and conversion of PUFAs into biojet fuel and high-value fatty acids have a great commercial potential.
Article
Chemistry, Multidisciplinary
Kyunglim Hyun, Younghwan Park, Songhyun Lee, Jueun Lee, Yeonwoo Choi, Seung-Jae Shin, Hyungjun Kim, Minkee Choi
Summary: Controlling metal-polymer interactions by supporting premade Pd particles on stable polymers with different ligating functionalities can tune the catalytic properties in acetylene partial hydrogenation. Polymers containing strongly ligating groups can form a polymer overlayer on the Pd surface, enabling selective acetylene adsorption and partial hydrogenation, while polymers with weakly ligating groups result in non-selective hydrogenation and fast deactivation. This study suggests that rational polymer design for tuning metal-polymer interactions provides an efficient way to synthesize selective and stable catalysts for hydrogenation.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Physical
Younghwan Park, Songhyun Lee, Kyunglim Hyun, Jueun Lee, Jeong Young Park, Ryong Ryoo, Minkee Choi
Summary: By introducing Am-PPS as a promoter, modifying the catalyst led to a significant enhancement of ethylene selectivity and acetylene hydrogenation activity, possibly due to the selective adsorption of acetylene and H-2 at the Am-PPS-Pd interface. The modified catalyst showed excellent long-term stability, demonstrating the unique potential of dynamic metal-polymer interaction in designing partial hydrogenation catalysts.
JOURNAL OF CATALYSIS
(2021)
Article
Chemistry, Physical
Kyungho Lee, Uzma Anjum, Cecilia Mondelli, Qian He, Shinya Furukawa, Javier Perez-Ramirez, Sergey M. Kozlov, Ning Yan, Thaylan Pinheiro Arajo
Summary: In this study, an atomic Pd-promoted ZnZrOx solid solution catalyst (Pd-ZnZrOx) was designed and synthesized, showing excellent activity and stability in the conversion of CO2 to methanol.
APPLIED CATALYSIS B-ENVIRONMENTAL
(2022)
Article
Engineering, Environmental
Myungwon Oh, Mingyu Jin, Kyungho Lee, Jeong-Chul Kim, Ryong Ryoo, Minkee Choi
Summary: In this study, the catalytic effects of Pt/Al2O3 on triglyceride deoxygenation were rigorously investigated. The results showed that the γ-Al2O3 and θ-Al2O3 phases effectively stabilized highly dispersed Pt particles and exhibited high catalytic activity. Additionally, large mesopores were essential for achieving maximum catalytic activity and suppressing catalyst fouling. Comparatively, the θ-Al2O3 phase generally had larger pore sizes and fewer Lewis acid sites, which inhibited the formation of heavy products and coke.
CHEMICAL ENGINEERING JOURNAL
(2022)
Review
Chemistry, Physical
Songhyun Lee, Hyungjun Kim, Ryong Ryoo, Jeong Young Park, Minkee Choi
Summary: Hydrogen spillover in nonreducible oxides is a controversial phenomenon in heterogeneous catalysis, and understanding its mechanism is crucial for the design of industrial catalysts. Research on zeolite-encapsulated metal catalysts has shown that hydrogen spillover can be utilized to improve catalytic performance.
Review
Chemistry, Multidisciplinary
Kyungho Lee, Yaxuan Jing, Yanqin Wang, Ning Yan
Summary: This article summarizes the catalytic conversion of biomass and waste plastics, with a focus on bond activation chemistry and catalyst design. Tracking the historical and recent developments, it is found that biomass and plastic have started to influence each other's fields, providing new insights and opportunities for existing technologies and future advancements.
NATURE REVIEWS CHEMISTRY
(2022)
Article
Engineering, Environmental
Mohammadreza Kosari, Kyungho Lee, Chao Wang, Sajjad Rimaz, Shenghui Zhou, Emmerson Hondo, Shibo Xi, Abdul Majeed Seayad, Hua Chun Zeng, Armando Borgna
Summary: Researchers successfully synthesized two types of uniform spherical hollow ZSM-5 (hZSM5), mhZSM5 and nhZSM5, and found that mhZSM5-AlCu showed higher activity and longer stability compared to other samples, with a DME production of 33.5 mg(DME).g(cat)(-1).h(-1). This may be attributed to its unique morphology and the presence of framework-intrinsic Al3+.
CHEMICAL ENGINEERING JOURNAL
(2023)
Article
Chemistry, Multidisciplinary
Yaejun Baik, Minjae Kwen, Kyungho Lee, Seunghyuck Chi, Susung Lee, Kanghee Cho, Hyungjun Kim, Minkee Choi
Summary: Ba-Ru/MgO catalysts are synthesized with an optimal Ru particle size and tailored BaO-Ru interfacial structures, which create a promoting effect through the separate storage of H+/e(-) pairs at the BaO-Ru interface. Chemisorbed H atoms on Ru dissociate into H+/e(-) pairs at the BaO-Ru interface, where selective capture of H(+) by strongly basic, nonreducible BaO leaves e(-) on Ru. The resulting electron accumulation in Ru facilitates N-2 activation and inhibits hydrogen poisoning during NH(3) synthesis.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Multidisciplinary Sciences
Kyungho Lee, Paulo C. D. Mendes, Hyungmin Jeon, Yizhen Song, Maxim Park Dickieson, Uzma Anjum, Luwei Chen, Tsung-Cheng Yang, Chia-Min Yang, Minkee Choi, Sergey M. Kozlov, Ning Yan
Summary: Metal promotion is commonly used to enhance the hydrogenation functionality of an oxide catalyst, but insufficient hydrogen delivery may compromise the enhancement effect. In this study, the authors introduced a strategy to promote a ZnZrOx methanol synthesis catalyst by optimizing the integration of ZnZrOx and Pd supported on carbon nanotube (Pd/CNT) to improve hydrogen activation and delivery. The Pd/CNT + ZnZrOx system demonstrated a 10-fold enhancement compared to the conventional Pd-promoted ZnZrOx catalyst in delivering hydrogen to a broad area on the ZnZrOx surface. It exhibited significantly boosted activity and excellent stability in CO2 hydrogenation to methanol, showing potential for practical implementation.
NATURE COMMUNICATIONS
(2023)
Article
Chemistry, Multidisciplinary
Kyungho Lee, Hao Yan, Qiming Sun, Zhenhua Zhang, Ning Yan
Summary: The conversion of CO2 to formate/formic acid and methanol is a promising method for utilizing CO2 in chemical and fuel synthesis, as well as reducing CO2 emissions. Creating efficient catalysts that can activate CO2 and H2 and selectively produce the desired products is a significant challenge. Recent advances in material synthesis and characterization techniques have allowed for a systematic understanding of catalytic reactions and the development of mechanism-guided catalysts.
ACCOUNTS OF MATERIALS RESEARCH
(2023)
Article
Chemistry, Physical
Yifan Sun, Ye Lv, Wei Li, Jinli Zhang, Yan Fu
Summary: In this study, PtRu electrocatalysts were fabricated on carbon paper via cyclic electrodeposition for the electrocatalytic hydrogenation (ECH) of phenol. The Pt3Ru3 catalyst exhibited excellent activity and stability for the conversion of phenol to cyclohexanol at ambient temperature and various current densities. The in situ Raman spectroscopy and kinetic study revealed the hydrogenation mechanism of phenol over Pt3Ru3 in acidic electrolyte, providing an effective electrochemical strategy for the facile construction of durable electrode materials and efficient phenol hydrogenation.
JOURNAL OF CATALYSIS
(2024)
Article
Chemistry, Physical
Amir Shahzad, Khezina Rafiq, Muhammad Zeeshan Abid, Naseem Ahmad Khan, Syed Shoaib Ahmad Shah, Raed H. Althomali, Abdul Rauf, Ejaz Hussain
Summary: Photocatalytic hydrogen production through water splitting is an effective method for meeting future energy demands. In this study, researchers synthesized a 1 % Ag2S/Cu2S co-doped CdZnS catalyst and found that it can produce hydrogen at a higher rate. The co-doping of Ag2S and Cu2S in the CdZnS catalyst showed a synergistic effect, with Ag2S promoting oxidation reactions and Cu2S promoting reduction reactions.
JOURNAL OF CATALYSIS
(2024)