Article
Chemistry, Physical
Carolin Rieg, Manuel Kirchhof, Katrin Gugeler, Ann-Katrin Beurer, Lukas Stein, Klaus Dirnberger, Wolfgang Frey, Johanna R. R. Bruckner, Yvonne Traa, Johannes Kaestner, Sabine Ludwigs, Sabine Laschat, Michael Dyballa
Summary: We developed a method to quantify the accessible Rh complexes in SBA-15 mesopores via solid state NMR spectroscopy. By combining P-31 MAS NMR and ICP-OES, the P/Rh ratio was determined, revealing that only up to 39% of the immobilized Rh complexes were accessible. With this methodology, the accessibility and spatial distribution of immobilized molecular catalysts can be evaluated quantitatively for the first time.
CATALYSIS SCIENCE & TECHNOLOGY
(2023)
Article
Engineering, Chemical
Sebastien Siradze, Jeroen Poissonnier, Morten Froseth, Ruth Elisabeth Stensrod, Richard H. Heyn, Joris W. Thybaut
Summary: Experimental assessment of hydroformylation of ethylene to propanal using a Rh(H)(PPh3)(3)(CO) catalyst showed an increase in reaction rate with temperature up to 100 degrees C, but catalyst deactivation at higher temperatures, attributed to lower total pressures and PPh3/rhodium molar ratios. Microkinetic modeling based on Wilkinson's dissociative mechanism was able to simulate experimental trends, with activation energies of 42 and 48 kJ mol(-1) for ethylene insertion and the oxidative addition of H-2, respectively. Ethylene insertion and oxidative addition of H-2 were identified as the most kinetically relevant steps in the reaction mechanism.
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
(2021)
Article
Engineering, Chemical
Yuntao He, Xiaxin Guo, Luyang Qiao, Runping Ye, Shanshan Zong, Xinyi Cao, Jiankai Cheng, Zhangfeng Zhou, Yuangen Yao
Summary: Rh complexes have shown great potential as catalysts for formaldehyde hydroformylation due to their ability to achieve high yields of glycolaldehyde under mild conditions. However, Rh-based heterogeneous catalysts often have limited activity in formaldehyde hydroformylation. This study developed four different supports loaded with Rh and found that silica-based catalysts exhibited higher conversion and selectivity for glycolaldehyde compared to Rh/Al2O3, attributed to the presence of more oxidized rhodium species and stronger metal support interactions. Furthermore, adjusting the structure of the silica support led to the synthesis of SBA-15 and HMS zeolites, which further improved the selectivity and yield of glycolaldehyde due to their larger surface area, suitable pore structures, and higher dispersion of Rh species.
BRAZILIAN JOURNAL OF CHEMICAL ENGINEERING
(2023)
Review
Chemistry, Multidisciplinary
Boyang Liu, Yu Wang, Ning Huang, Xiaocheng Lan, Zhenhua Xie, Jingguang G. Chen, Tiefeng Wang
Summary: This review summarizes the developments of catalysts for heterogeneous hydroformylation in the last decade and proposes potential modification methods for future improvements. The hydroformylation properties of different reactants are compared in order to emphasize the unique challenges faced by various olefins. The catalytic properties can be tuned through electronic effects, steric hindrance, and reaction condition optimization.
Article
Chemistry, Physical
Jie Wei, Maoshuai Li, Jie Ding, Weikang Dai, Qi Yang, Yi Feng, Cheng Yang, Wanxin Yang, Ying Zheng, Mei-Yan Wan, Xinbin Ma
Summary: By establishing a quantitative structure-activity relationship (QSAR) model with a class of phosphine-Rh complexes, this study found that the hydroformylation activity is mainly controlled by electronic factors. Computational mechanistic pathway analysis demonstrated the significant impact of electronic features on TOF-determining transition state, and H-2 distortion energy analysis rationalized the variation of reaction outcomes.
Article
Multidisciplinary Sciences
Peng Gao, Guanfeng Liang, Tong Ru, Xiaoyan Liu, Haifeng Qi, Aiqin Wang, Fen-Er Chen
Summary: Single-atom Rh catalysts show superior activity in olefins hydroformylation but limited success in regioselectivity control. By developing a Rh1 single-atom catalyst with nanodiamond as support, the catalyst achieved good to excellent regioselectivities in hydroformylation of arylethylenes, comparable to homogeneous counterparts. The coordination interaction between Rh-1 and surface phosphorus species was clarified by P-31 solid-state NMR and X-ray absorption spectroscopy.
NATURE COMMUNICATIONS
(2021)
Article
Chemistry, Organic
Runtong Zhang, Xin Yan, Caiyou Chen, Ya-Nan Duan, Xintong He, Shao-Tao Bai, Xumu Zhang
Summary: This paper demonstrates the integration of a Milstein-type Ru-PNN catalyst and a Rh-Tribi/Tetrabi catalyst, resulting in highly improved isomerization linear selective hydroformylation of internal alkenes. The obtained yields exhibit excellent linear selectivities and activities compared to the Ru-PNN/Rh-Bisbi system.
JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Physical
Ann-Katrin Beurer, Manuel Kirchhof, Johanna R. Bruckner, Wolfgang Frey, Angelika Baro, Michael Dyballa, Frank Giesselmann, Sabine Laschat, Yvonne Traa
Summary: The study introduces a method for selectively functionalizing the mesoporous surface, which has been successfully applied to the asymmetric Rh-catalyzed 1,2-addition reaction. The results demonstrate that the catalyst selectively immobilized in the mesopores shows better catalytic performance, further advancing the field of catalysis.
Article
Chemistry, Applied
Zhengtian Pu, Haibin Yin, Xinlong Ma, Jin Zhao, Jie Zeng
Summary: This study reports the evolution of initially inactive RhOx clusters on Al2O3 into catalytically active oxygen vacancies and Rh single atoms via mobile Rh-CO intermediates during hydroformylation of propene. The activated catalyst exhibits high specific activity for the reaction and sheds light on the dynamic evolution of catalysts.
CHINESE JOURNAL OF CATALYSIS
(2023)
Article
Chemistry, Applied
Wenlan Cai, Xiaoyan Ni, Fanyong Meng, Lin Sun, Runwei Wang, Sen Lin
Summary: The acid-free synthesis of Ga-containing SBA-15 mesoporous materials allows for tuning their morphological and acidic properties. Ga-SBA-15 exhibits high acid amount and adjustable morphology due to the presence of dispersed bending particles. The improved interparticle-type mesoporosity of Ga-SBA-15 provides highly accessible active sites for large molecules. Ga-SBA-15 also shows a shift from Bro center dot nsted-type acidity to Lewis-type acidity.
MICROPOROUS AND MESOPOROUS MATERIALS
(2022)
Article
Energy & Fuels
Norshakirah Ahmad Rashidi, Elnida Mustapha, Yeow Yean Theng, Noor Azira Abdul Razak, Najihah Abdul Bar, Khairul Basyar Baharudin, Darfizzi Derawi
Summary: Waste cooking oil is an attractive feedstock for producing advanced biofuels due to its low cost and abundant availability. This study focused on the synthesis and analysis of mesoporous bimetallic catalysts for the catalytic deoxygenation of waste cooking oil. The results showed that the catalyst with 10% Ni-Fe/SBA-15 had the highest liquid yield but low selectivity towards the diesel fraction, while the catalyst with 5% Ni-Co/SBA-15 had the highest selectivity towards the diesel fraction.
Article
Chemistry, Physical
Jing Ma, Meizhe Liu, Mingxuan Zhu, Yutong Wang, Yamei Zhou, Baohe Wang
Summary: In this study, the formation process of catalyst active species after CO insertion and the reaction mechanism of ethylene hydroformylation to propionaldehyde were studied using the density functional theory (DFT) method. It was found that the polymer catalyst of crosslinking mode 2 is more favorable for the CO coordination of the main reaction, while that of crosslinking mode 1 can effectively improve the selectivity of ethylene hydroformyl to propionaldehyde. The Rh activity and Rh-P bond strength changed alternately in the step of propionaldehyde synthesis, and the change trend of the two is inversely proportional.
CATALYSIS SCIENCE & TECHNOLOGY
(2022)
Article
Chemistry, Applied
Vahide Nuran Mutlu, Selahattin Yilmaz
Summary: The glycosidation of glucose with n-butanol was studied using sulphated Zr and tungstophosphoric acid incorporated SBA-15 catalysts, showing improved acidity and higher yields of butyl glucoside. The TPA-SBA-15 catalyst demonstrated the highest activity and selectivity, with stable and reusable performance. Further studies on reaction temperature and catalyst amount were conducted to optimize the reaction parameters.
Article
Engineering, Environmental
Da Yang, Shu Tao, Houyu Zhu, Zhidong Wang, Wenwen Gao, Jinggang Yu, Minmin Wang, Guangxun Sun, Junxi Li, Hsiao-Chien Chen, Bin Liu, Yongming Chai, Yuan Pan
Summary: In this study, a dual-active sites coupling catalyst containing triphenyl phosphine-coordinated Rh clusters and Rh-N4 single atomic sites was reported for hydroformylation of olefins. The catalyst exhibited remarkable activity, with a high turnover frequency value and improved activity due to the presence of PPh3. Furthermore, the catalyst showed recyclability without obvious deactivation, providing a novel design concept for the construction of synergistic heterogeneous hydroformylation catalysts from the atomic scale.
CHEMICAL ENGINEERING JOURNAL
(2024)
Article
Chemistry, Applied
Christopher M. A. Parlett, Hamidreza Arandiyan, Lee J. Durndell, Mark A. Isaacs, Antonio Torres Lopez, Roong J. Wong, Karen Wilson, Adam F. Lee
Summary: The article demonstrates a method for continuous flow synthesis of SBA-15 at high yield at 80 degrees C using a simple tube reactor. The resulting SBA-15 exhibits excellent textural properties and far higher productivity than previously reported in batch or flow synthesis.
MICROPOROUS AND MESOPOROUS MATERIALS
(2022)
