To systematically explore the effects of the synthesis conditions on the porosity of hyper-cross-linked polymers (HCPs), a series of 9-phenylcarbazole (9-PCz) HCPs (-) has been made by changing the molar ratio of cross-linker to monomer, the reaction temperature , the used amount of catalyst and the concentration of reactants. Fourier transform infrared spectroscopy was utilized to characterize the structure of the obtained polymers. The TG analysis of the HCPs showed good thermal stability. More importantly, a comparative study on the porosity revealed that: the molar ratio of cross-linker to monomer was the main influence factor of the BET specific surface area. Increasing the reaction temperature or changing the used amount of catalyst could improve the total pore volume greatly but sacrificed a part of the BET specific surface area. Fortunately changing the concentration of reactants could remedy this situation. Slightly changing the concentration of reactants could simultaneously obtain a high surface area and a high total pore volume. The BET specific surface areas of was up to 769 m g with narrow pore size distribution and the CO adsorption capacity of was up to 52.4 cm g (273 K/1.00 bar).
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http://dx.doi.org/10.3762/bjoc.15.279 | DOI Listing |
Acc Chem Res
January 2025
Key Lab of Biomass Chemical Engineering of Ministry of Education, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou 310027, China.
ConspectusFor chemical reactions with complex pathways, it is extremely difficult to adjust the catalytic performance. The previous strategies on this issue mainly focused on modifying the fine structures of the catalysts, including optimization of the geometric/electronic structure of the metal nanoparticles (NPs), regulation of the chemical composition/morphology of the supports, and/or adjustment of the metal-support interactions to modulate the reaction kinetics on the catalyst surface. Although significant advances have been achieved, the catalytic performance is still unsatisfactory.
View Article and Find Full Text PDFHeliyon
January 2025
Department of Mathematics, University of Dhaka, Dhaka 1000, Bangladesh.
This study analyzes the influences of surface reactions on the natural convective flow, temperature, and oxygen concentration distributions in vertically placed multilayered cavities. A mathematical model for this problem is formulated with proper boundary conditions. At first, the governing equations are made dimensionless using the variable transformations.
View Article and Find Full Text PDFAcc Chem Res
January 2025
Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States.
ConspectusReactions of gas phase molecules with surfaces play key roles in atmospheric and environmental chemistry. Reactive uptake coefficients (γ), the fraction of gas-surface collisions that yield a reaction, are used to quantify the kinetics in these heterogeneous and multiphase systems. Unlike rate coefficients for homogeneous gas- or liquid-phase reactions, uptake coefficients are system- and observation-dependent quantities that depend upon a multitude of underlying elementary steps.
View Article and Find Full Text PDFAdv Mater
January 2025
School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, Jiangsu, 210023, China.
Hydrogen evolution reaction (HER), as one of the most advanced methods for the green production of hydrogen, is greatly impeded by inefficient mass transfer. Here we present an efficiently reactant enriched and mass traffic system by integrating high-curvature Pt nanocones with 3D porous TiAl framework to enhance mass transfer rate. Theoretical simulations, in situ Raman spectroscopy and potential-dependent Fourier transform infrared spectroscopy results disclose that the strong local electric field induced by high-curvature Pt can greatly promote the HO supply rate during HER, resulting in ∼1.
View Article and Find Full Text PDFAnal Chem
January 2025
State Key Laboratory of Silicate Materials for Architectures, Wuhan University of Technology, Wuhan 430070, China.
An in situ monitoring reaction can better obtain the variations during the progression of the photocatalytic reaction. However, the complexity of the apparatus and the limited applicability of substances are the common challenges faced by most in situ monitoring methods. Here, we invented an in situ infrared optical fiber sensor to monitor the reactants and products during photocatalytic reaction.
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