Facile synthesis of hierarchical manganese-containing TS-1 and its application on the oxidation of cyclohexanone with molecular oxygen

A green template-assisted synthesis of hierarchical TS-1 with excellent catalytic activity and recyclability for the oxidation of 2,3,6-trimethylphenol

Novel titanium-containing precursors for the fabrication of hierarchical TS-1 and the enhanced catalytic performance for olefins

Substrate specificity in the biomimetic catalytic aerobic oxidation of styrene and cyclohexanone by metalloporphyrins: kinetics and mechanistic study

Developing efficient heterogeneous catalysts for cyclic olefins epoxidation is highly attractive for meeting the growing need for various cyclic epoxides. Herein, hierarchical TS-1 zeolite with relatively abundant mesopores and less amount of surface hydroxyl groups was obtained by hydrothermal modification of an as-synthesized TS-1 zeolite with a mixed solution of ammonia, tetrapropylammonium bromide (TPABr) and KCl. The post-modified TS-1 zeolite exhibited much higher catalytic activity (52% conversion) and epoxide selectivity (98%) for the epoxidation of cyclopentene than the conventional TS-1 zeolites. The excellent catalytic activity of the hierarchical TS-1 could be mainly assigned to the enhancement of the mass transport ability and the accessibility of the active Ti species, while the improvement of epoxidation selectivity may be mainly related to the introduction of a certain amount of K+ that can effectively modulate the coordination environment of Ti species as well as the polarity of the zeolite. This work demonstrated that a highly active and selective catalyst for the H2O2-mediated cyclopentene epoxidation could be obtained by concurrently generating mesopore and extinguishing the unfavorable defective hydroxyl groups through the simple hydrothermal treatment of the conventional TS-1 zeolite with a mixed base/salt solution.

Because of its unique pore structure, good hydrothermal stability and high specific surface area, hierarchical TS-1 zeolite (HTS-1) has become an important catalyst for the deep oxidative desulfurization of fuel oils. In this work, HTS-1 has been successfully synthesized by a hydrothermal crystallization method using the C-SiO2 composite as both silicon source and mesoporous template, tetrapropylammonium hydroxide as microporous template, and tetrabutylorthotitanate as titanium source. The C-SiO2 composite is obtained by mild carbonization of the SiO2/T-40 (Tween 40) xerogel, which is prepared by the two step sol-gel method. The reaction conditions for the oxidative desulfurization (ODS) of dibenzothiophene (DBT) and 4,6-dimethyldibenzothiophene (4,6-DMDBT) over HTS-1 are optimized systematically, and the recycling performances of HTS-1 are investigated in detail. After the 15th run, HTS-1 still maintains high DBT conversion (90.6%) and 4,6-DMDBT conversion (86.0%) without deactivation. The samples before and after recycle tests are characterized by XRD, FT-IR, CHN analysis, UV-Vis and SEM techniques. The results indicate that the crystal structure and morphology of regenerated HTS-1 samples are well kept, which accounts for the good structural stability and reusability of HTS-1. In addition, active intermediates for the ODS of bulky organic sulfides over HTS-1, i.e., Ti-peroxo (Ti-OOtBu) species, are captured by the UV-Vis technique. Finally, a possible reaction mechanism for the ODS process over HTS-1 is proposed.

Synthesis of hierarchical TS-1 zeolite via a novel three-step crystallization method and its excellent catalytic performance in oxidative desulfurization

Narrowing the mesopore size distribution in hierarchical TS-1 zeolite by surfactant-assisted reorganization

Hierarchical TS-1 zeolite as an efficient catalyst for oxidative desulphurization of hydrocarbon fractions

Synthesis, characterization and catalytic performance of hierarchical TS-1 with carbon template from sucrose carbonization

Hierarchical manganese-containing TS-1 zeolite for the direct oxidation of cyclohexane to adipic acid with molecular oxygen: Synergy between matrix Ti and Mn species

Facile synthesis of hierarchical TS-1 zeolite without using mesopore templates and its application in deep oxidative desulfurization

Synthesis and catalytic performance of hierarchical TS-1 directly using agricultural products sucrose as meso/macropores template

P123 lamellar micelle-assisted construction of hierarchical TS-1 stacked nanoplates with constrained mesopores for enhanced oxidative desulfurization

We calculate the greenhouse gas (GHG) emissions and energy consumption of two French beekeeping systems, one amateur system (Amat) and one professional system (Pro) with 300 hives. The GHG emissions reach 2.7 kgCO2eq/kg of honey for Amat and 1.49 for Pro. Travel to visit the apiaries accounted for 59% of the total GHG emissions for Amat and 28% for Pro, and sugar accounted for 21% and 41%, respectively. The energy consumption reached 37.4 MJ/kg for Amat and 19.9 MJ/kg for Pro; travel represented 65% of energy consumption for Amat and 34% for Pro, and sugar accounted for 15% and 32%, respectively. The sensitivity analysis revealed that the most important factor influencing GHG emissions was the bee mortality rate, followed by the distances covered by vehicles and the level of sugar use. The average energy consumption per kg of dry matter produced between Amat and Pro is close to that observed for French dairy cattle production. The GHG emissions are well below those of dairy production, by factors of 3.7 and 6.6 for Amat and Pro, respectively. Finally, we make the following recommendations to improve the environmental performance of beekeeping farms, in terms of GHG emissions and energy consumption, in the French context but a priori also in other contexts i) maintain efforts to identify and reduce causes of bee mortality; ii) limiting distances traveled and using low-energy, low-carbon vehicles; and iii) using well-insulated hives. We also provide the GHG emission and energy consumption factors for the artificial swarms purchased.

Thailand’s civil aviation industry has expanded rapidly in the past ten years resulting in increasing aviation greenhouse gas (GHG) emissions and energy consumption. The rapid growth in air transport is anticipated to continue further. Presently, domestic aviation and the economy of many countries are recovering rapidly in the post-COVID-19 period, resulting in fuel consumption and GHG emissions gradually increasing again. However, despite implementing the ICAO’s CORSIA (International Civil Aviation Organization’s Carbon Offsetting and Reduction Scheme for International Aviation) rule for international aviation, GHG emissions in the domestic aviation sector are largely unregulated. Moreover, the literature lacks a GHG emissions analysis that considers this sector’s potential growth and mitigation policies for future GHG emissions. To close the gap, this study conducted a GHG emissions analysis from this sector under various scenarios through 2050 using historical data during 2008–2020 to forecast future trends. It evaluates the impact of the mitigation policies, such as fuel switching and aircraft technology, on improving fuel efficiency due to technological advancements in aircraft and carbon pricing. The results show that the fuel switching option would result in a significant long-term reduction in GHG emissions, whereas the carbon pricing option and aircraft technology option are desirable in reducing GHG emissions in the short term. Therefore, to meet GHG emissions reduction targets more successfully, all measures must be simultaneously executed to address short- and long-term mitigation strategies. These findings have significant implications for both present and future GHG emissions reduction measures, supporting Thailand’s 2050 climate targets and energy efficiency policies as the domestic aviation industry adjusts.