Enhancement of the Catalytic Activity of Double Metal Cyanides for the Oxidation of Styrene by the Presence of Included Alcohols

Langmuir, Journal Year: 2022, Volume and Issue: 38(28), P. 8696 - 8707

Published: July 7, 2022

In recent years, people have focused on the development of simple and efficient heterogeneous catalysts for styrene epoxidation reaction. this work, a FeCo double metal cyanide (DMC) was modified with C1 to C6 linear alcohols, prepared materials were used catalyze reaction in various solvents. It is noteworthy that conversion mainly affected by modification while selectivity oxide (SO) obviously influenced solvent. DMC along MeOH exhibits best catalytic performance, rate 96% SO 86%, N,N-dimethylformamide (DMF) Various physical chemical methods analyze structures compositions materials. To clarify mechanism improvement, we set up an original approach investigate kinetics adsorption process between oxidant catalyst, using isothermal titration calorimetry (ITC). The obtained results illustrate surface can be dramatically promoted presence MeOH. Such difference thus explains significant improvement its activity This study provides new fundamental understanding

Language: Английский

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Thermal Decomposition of Ammonium Perchlorate Encapsulated with Copper(II)/Iron(III) Oxide Nanoparticles

Central European Journal of Energetic Materials, Journal Year: 2023, Volume and Issue: 20(2), P. 114 - 137

Published: June 30, 2023

Thermal decomposition of ammonium perchlorate (AP), as a high energy oxidizer in composite solid rocket propellants (CSRP), greatly affects the burning rate propellant.This paper summarizes results study synergistic catalytic activity nano-CuO/Fe2O3 nanoparticles on thermal AP.AP micro-particles are efficiently encapsulated with 1 and 5 wt.% nano-CuO and/or nano-Fe2O3 by fast-crash solventantisolvent technique.The efficiency encapsulation method was confirmed using FT-IR spectroscopy.Morphological characterization, performed SEM-EDS microscopy, showed that provides recrystallization deagglomeration AP uniform nano-catalyst distribution.The nano-CuO/ investigated DSC, an increase released heat observed from 1453 to 1628 J/g.The activities nano-catalysts were proven decreasing HTD merging low temperature peak.The highest effect obtained after encapsulating combined 50/50 mass ratio due multiple mechanisms nano-Fe2O3.The

Language: Английский

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Catalytic performances of fluorine-doped graphene/Pb composite for thermal decomposition of ammonium perchlorate

Fullerenes Nanotubes and Carbon Nanostructures, Journal Year: 2022, Volume and Issue: 30(12), P. 1171 - 1179

Published: May 26, 2022

Fluorine-doped graphene supported PbO (F-rGO/PbO) composite was prepared through a facile water bath method to study an improvement strategy for its catalytic performance in thermal decomposition of ammonium perchlorate (AP). The characterization results showed that the with size 20 ∼ 30 nm are highly dispersed on surface F-doped (F-rGO). Compared other samples, F-rGO/PbO exhibited superior performance, as 3 wt% catalyst added AP, peak temperature HTD reduced by 124°C, and LTD increased 8°C. released apparent specific heat AP catalyzed (3603.7 J/g) is five times pure (603.5 J/g). doping F atoms BET areas F-rGO carrier enhanced content hydroxyl groups graphene, which improved rate AP. While NPs further provide more active sites during

Language: Английский

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Modification of Combustion Performance and Mechanical Properties of HTPB-Based High-Energy Composites with Non- Reactive Polyhedral Oligomeric Silsesquioxane Nanostructures

Research Square (Research Square), Journal Year: 2023, Volume and Issue: unknown

Published: Dec. 13, 2023

This research effort was aimed at elucidating the effect of Octa-isobutyl-silsesquioxane (OIBS) and Octa-phenyl-silsesquioxane (OPS) nanostructures on mechanical Combustion Performance Hydroxyl-terminated polybutadiene (HTPB) High-energy composites (HECs). included investigation properties in different concentrations 0.1, 0.5, 1.5, 2.5 wt% Polyhedral Oligomeric Silsesquioxane (POSS). It should be noted that concentration 0.1 POSS, elongation observed along with a decrease strength composite On contrary, increasing from to wt%, an increase occurred. These findings were more pronounced for OPS than OBS. In addition, combustion performance HEC mixed 0.5 POSS evaluated. Then original samples, these showed burning rate sample. Significantly, HECs containing OIBS exceeded OPS. Findings obtained through XRD (X-ray Diffraction) SEM (Scanning Electron Microscopy) analysis proved efficiency HECs. conclusion, mechanism proposed improve by distributed matrix.

Language: Английский

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Influence of BaZnCuO3 and BaZnCuO3/rGO on the thermal decomposition of AP and NTO

Authorea (Authorea), Journal Year: 2022, Volume and Issue: unknown

Published: Sept. 21, 2022

BaZnCuO3 (BZC) was synthesized using the sol-gel method. The BZC incorporated in reduced graphene oxide (rGO) to produce BZC/rGO composite. catalysts were characterized Raman, powder X-ray diffraction (XRD), and Ultraviolet-visible (UV-Vis) analysis. comparative effect of BZC:rGO composite studied on thermal decomposition 3-nitro-3H-1,2,4-triazol-5-one (NTO) Ammonium Perchlorate (AP) simultaneous Thermo-gravimetric technique (TG-DTA). a better catalyst for decreasing temperature thermo-kinetic parameters both AP NTO compared can reduce by 121 oC, 46 respectively. findings support as possible thermolysis AP.

Language: Английский

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