Low-temperature Oxidation Of Propane Research Articles

Highly efficient Ru/CeO2 catalyst using colloidal chemical method for propane oxidation

Although supported-Ru catalysts have been widely studied for the light alkane oxidation root in their lower cost compared to Pt and Pd, developing Ru-based catalysts with high efficiency for low-temperature light alkane elimination remains a significant challenge. Herein, Ru/CeO2 catalysts were prepared utilizing the colloidal synthesis (Ru/CeO2-CS) and compared with the catalyst prepared with the traditional impregnation method (Ru/CeO2-IM) in the textural properties and catalytic propane oxidation. It was discovered that Ru/CeO2-CS sample contained a higher concentration of active Ru − O − Ce interface and oxygen vacancies attributed to the strong Ru-CeO2 interaction, which further enhanced the redox capacity. Besides, the lower valence state of Ru species and higher contents of Lewis acid sites on Ru/CeO2-CS sample boosted the adsorption, dissociation, and activation of propane, thus promoting the deep oxidation of propane to CO2 and H2O. The reaction mechanism of propane oxidation was revealed by in-situ DRIFTS, and both the catalysts showed bands related to acrylate species, suggesting that propane underwent an acrylate oxidation pathway on Ru/CeO2-CS and Ru/CeO2-IM samples. The distinct textural properties of these catalysts resulted in Ru/CeO2-CS synthesized by colloidal methods showing a T90 of 170 °C, and Ea of 50.9 ± 1.8 kJ·mol−1, markedly lower than Ru/CeO2-IM prepared with the traditional impregnation method. Apart from the activity, the Ru/CeO2-CS sample obtained superior water resistance, thermal stability, and durability. This comprehensive work provides promising insights into low-temperature propane oxidation.

Fe-doped MnO2 as an efficient catalyst for low temperature propane oxidation

Manganese oxides were received extensive attention on account of its low cost, variable valence state and excellent redox properties. Herein, we successfully prepared various Fe-doped MnO2 catalysts to further improve the catalytic activity of MnO2 on propane. Physicochemical characterization results displayed that with the increase of Fe doping amounts, the crystalline phase of MnO2 gradually changed from α-MnO2 and β-MnO2 to Fe2O3, the particle size of catalysts decreased and the specific surface area increased. However, increasing the content of Fe could not monotonically enhance the catalytic performance of catalysts on propane. When the molar ratio of Fe/Mn was 0.25, the largest amount of Mn4+ species and lattice oxygen species were exposed on the surface of Mn8Fe2, and showed the best low temperature reducibility, which was ascribed to the synergistic effect between Mn and Fe was enhanced. It presented optimal catalytic activity for propane oxidation with temperature of propane conversion at 90% (T90) as low as 279 °C under 0.1% propane and 5% O2. This work provided a new way to design and synthesize efficient non-noble metal catalysts for the elimination of propane, which had certain application value.

Chemical insight into the ozone-assisted low-temperature oxidation of propane

Ozone addition is not only a promising method for combustion control and enhancement but also provides a reliable platform to benchmark low-temperature oxidation chemistry. Studies of ozone-doped combustion provide additional insight into combustion chemistry at lower temperatures. This paper studies the ozone-assisted low-temperature oxidation of propane in an atmospheric jet-stirred reactor (JSR) from 350 to 770 K. More than twenty species are measured and quantified using synchrotron vacuum ultraviolet photoionization mass spectrometry (SVUV-PIMS). The experimental results show that even at temperatures as low as 450 K, the reaction of propane is initiated by Ö atoms that originate from the thermal decomposition of ozone. The reactivity of propane reaches a maximum at 650 K, decreases in the temperature range of 650 – 740 K, and then slightly increases from 740 to 770 K. The propane oxidation behavior observed in this study is effectively captured by NUIGMech1.3 combined with a Princeton ozone sub-mechanism. However, the mole fractions of certain species such as, CO, H2O, and H2O2 are over-estimated by the mechanism at temperatures above 700 K. Kinetics analyses indicate that fuel oxidation and intermediate species formation are sensitive to the reaction temperature which determines the competing reactions involving propyl-peroxy radicals and the formation of ȮH and HȮ2 radicals. These findings are significant in terms of improving the core mechanism and acquiring a deeper comprehension of the ozone-assisted low-temperature oxidation chemistry of alkanes.

Urea-H2O2 defect engineering of δ-MnO2 for propane photothermal oxidation: Structure-activity relationship and synergetic mechanism determination

Photothermal catalysis has an advantage in effective and economical elimination technology of volatile organic compounds (VOCs) in the ascendant. Herein, various surface defect engineering routes were adopted to enhance the low-temperature propane oxidation of δ-MnO2. Compared to reducing etchants urea and vitamin C, δ-MnO2 treated with urea - H2O2 exhibited an excellent thermal (T90 = 240 ℃) and photothermal (T90 = 196 ℃) activities of propane oxidation. Urea - H2O2 treatment provided high concentration of Mn4+ and surface-active oxygen (Mn4+-Osur) species as surface-active sites, and produced numerous oxygen vacancies to improve charge separation and superoxide species generation capacity. Thus, the photothermal conversion efficiency and low-temperature reducibility were remarkably enhanced. Furthermore, the photothermal synergistic catalytic mechanism was proposed based on in-situ diffuse reflectance infrared Fourier transform spectroscopy and control experiments. The strategy here offered insight into the rational design of efficient transition catalysts, and in-depth understanding of the photothermal catalytic VOCs removal mechanism.

A wide range experimental study and further development of a kinetic model describing propane oxidation

This work presents an experimental and kinetic modeling study of propane oxidation. Ignition delay times of propane were measured in a high-pressure shock tube and in rapid compression machines in the temperature range 689 – 1700 K at equivalence ratios of 0.5, 1.0 and 2.0 in ‘air’, for a wide range of pressures from 20 to 90 bar. CO and H2O mole fraction profiles for propane oxidation were measured in a shock tube behind reflected shock waves in the temperature range 1370–1840 K at equivalence ratios of 0.5, 1.0 and 2.0 and at a pressure of approximately 1.3 atm. Moreover, propane oxidation was studied using a jet-stirred reactor coupled to a synchrotron vacuum ultraviolet photoionization mass spectrometer at low temperatures in the range 565 – 690 K and at a pressure of 1 atm. This wide range of experimental datasets for propane oxidation was used to reoptimize and update our previous kinetic mechanisms, AramcoMech3.0 and NUIGMech1.1. In the current mechanism, NUIGMech1.3, the thermochemical parameters of all species relevant to low-temperature propane oxidation chemistry, including propyl-peroxyl, hydroperoxyl-propyl, hydroperoxyl-propyl-peroxyl, and carbonyl-hydroperoxide radicals, are updated based on newly calculated values at the CCSD(T)-F12/TZ-F12//B2PLYPD3/TZ///B2PLYP-D3/TZ level of theory. The improvements made in the thermochemical values and in the kinetic parameters for the low-temperature propane oxidation reactions in NUIGMech1.3 result in better model agreement with the new IDTs and speciation data, including carbon monoxide, formaldehyde, propene, acetaldehyde and various minor products such as ethylene, acetic acid, acrolein as well as various hydroperoxide and cyclic ether species.

Kinetic insights into plasma-assisted low-temperature oxidation of propane with synchrotron photoionization mass spectrometry

The present study investigates the chemical kinetics of low-temperature oxidation of propane activated by nanosecond pulsed dielectric barrier discharge in a flow reactor. Molecular beam mass spectrometry with tunable synchrotron vacuum ultraviolet photoionization (SVUV-PIMS) is employed for components identification and quantification. A series of hydrocarbons and oxygenated intermediates are observed, including fuel-specific species reported for the first time in this system like propyl hydroperoxide (C3H7OOH), acrolein (C3H4O2), oxetane (-CH2CH2CH2O-), methyloxirane (-CH(CH3)CH2O-), and propanol (n-/i-C3H7OH), which provide original kinetic information in the plasma-assisted low-temperature oxidation of propane. The detection of alkyl hydroperoxide (ROOH) demonstrates the existence of alkyl peroxy (RO2) formed through oxygen addition to alkyl (R) and the detection of cyclic ethers provides evidence for the presence of hydroperoxyl alkyl (QOOH). A kinetic model incorporating plasma chemistry and combustion chemistry is developed for plasma-assisted oxidation of propane. Path fluxes of fuel consumption and oxygenated intermediates formation are provided based on model analysis. Besides H abstractions by the OH radical, reactions activated by plasma involving electron impact dissociation, O(1D)/Ar* quenching dissociation, and ionization contribute much to fuel consumption. The formed propyl (n-/i-C3H7) are exclusively consumed through oxygen addition producing propyl peroxy (n-/i-C3H7O2). Propyl peroxy can participate in self- and cross-reactions yielding various oxygenated intermediates such as aldehydes, ketones, alcohols, and propoxy (n-/i-C3H7O). Discrepancies between simulations and experiments suggest that further kinetic studies on low-temperature mechanisms, including propyl peroxy related reactions for plasma-assisted combustion modeling, are still desired.

A-site cation exfoliation of amorphous SmMnxOy oxides for low temperature propane oxidation

Propane removal is one of the critical challenges in reducing volatile organic compounds and automotive exhaust emission. Being a non-polar molecule with saturated C-H bonds, low temperature propane oxidation hinges on efficient dehydrogenation of terminal methyl by active lattice oxygen. We report here the fabrication of a multi-component MnOx/SmMn2Ox catalyst for propane combustion via A-site cation exfoliation of amorphous SmMn2Ox. The formation of surface mesostructured MnOx induced by partial removal of Sm cations greatly boosts C-H bond activation and formation of formate species. Amorphous SmMn2Ox base with rich oxygen conservation as well as robust connection between MnOx and support accelerates decomposition of formate species exhibiting one of the best propane catalytic activity with 90.7% conversion at 237 °C under 60,000 ml·g−1·h−1 space velocity, together with excellent thermal endurance and water resistance. Rate determining steps for propane oxidation over amorphous SmMnxOy, i.e. C-H bond activation and formate decomposition, were analyzed through propane temperature programmed surface reaction (C3H8-TPSR) and in situ diffuse reflectance infrared Fourier transform spectroscopy (in situ DRIFTS), in which SmMnxOy showed the best surface lattice oxygen activity and eminent ability of propane deep oxidization.

TEXTURAL AND CATALYTIC FEATURES OF SILICON SURFACE MODIFIED WITH ZnO IN THE REACTION OF HOMOGENOUS-HETEROGENEOUS ACTIVATION OF PROPANE-OXYGEN MIXTURES AT LOW PRESSURES

The textural and catalytic characteristics of the surface of silica gel modified with zinc oxide by the sol-gel method and by means of a chemical transport reaction (CTR) have been studied. It was found that catalytic activity of the obtained contacts depends on both the nature and the structural and textural characteristics of the supported ZnO. Using the example of the reaction of low-temperature oxidation of propane, it was found that lower limit of the release of radicals from the surface into the volume with the CTR modification method is lower by 15–20 degrees than in the case of the sol-gel method. It was shown that the catalyst obtained by applying the active phase on the surface of the support by the CTR method is more efficient due to the energy homogeneity of its active centers and the texture characteristics of the surface.

Defect enhanced CoMnNiOx catalysts derived from spent ternary lithium-ion batteries for low-temperature propane oxidation

Herein, a feasible strategy was reported to reuse the waste ternary lithium-ion batteries (TLIBs) as precursors to develop efficient CoMnNiOx catalysts for propane oxidation. Interestingly, the T90 value of the defect enhanced-CoMnNiOx catalyst for propane oxidation was only 200 °C. The de-aluminum and de-lithium process generated by the alkaline etching promoted the increase of the oxygen vacancy defects, which was confirmed by ICP-OES, XPS, EPR and DFT calculations. At the atomic level, the oxygen vacancies near the aluminum and lithium vacancies (NiO-Alv-Ov and NiO-Liv-Ov) were more likely to promote the activation of oxygen molecules. Furthermore, it was observed that the reducibility, acidity and lattice oxygen mobility of the defective CoMnNiOx catalyst were boosted by the presence of abundant oxygen vacancy defects, and thus enhancing the catalytic activity. Remarkably, the TLIBs recycling and defect enhancement engineering are conducive for the development of the green and efficient catalysts for VOCs oxidation.

N-doped CoAl oxides from hydrotalcites with enhanced oxygen vacancies for excellent low-temperature propane oxidation

A series of nitrogen-doped CoAlO (N-CoAlO) were constructed by a hydrothermal route combined with a controllable NH3 treatment strategy. The effects of NH3 treatment on the physico-chemical properties and oxidation activities of N-CoAlO catalysts were investigated. In comparison to CoAlO, a smallest content decrease in surface Co3+ (serving as active sites) while a largest increased amount of surface Co2+ (contributing to oxygen species) are obtained over N-CoAlO/4h among the N-CoAlO catalysts. Meanwhile, a maximum N doping is found over N-CoAlO/4h. As a result, N-CoAlO/4h (under NH3 treatment at 400°C for 4 hr) with rich oxygen vacancies shows optimal catalytic activity, with a T90 (the temperature required to reach a 90% conversion of propane) at 266°C. The more oxygen vacancies are caused by the co-operative effects of N doping and suitable reduction of Co3+ for N-CoAlO/4h, leading to an enhanced oxygen mobility, which in turn promotes C3H8 total oxidation activity dominated by Langmuir-Hinshelwood mechanism. Moreover, in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTs) analysis shows that N doping facilities the decomposition of intermediate species (propylene and formate) into CO2 over the catalyst surface of N-CoAlO/4h more easily. Our reported design in this work will provide a promising way to develop abundant oxygen vacancies of Co-based catalysts derived from hydrotalcites by a simple NH3 treatment.

Mesoporous Co–Mn Spinel Oxides as Efficient Catalysts for Low Temperature Propane Oxidation

Mesoporous Co–Mn Spinel Oxides as Efficient Catalysts for Low Temperature Propane Oxidation

Boosting low temperature propane oxidation on bamboo-mediated biosynthesis of LaCoO3 via the optimized chelating effect

A pure phase of LaCoO3 perovskite was low-temperature synthesized via a novel bamboo-mediated sol-gel route, which can meanwhile regulate Co species and oxygen vacancies of the catalyst by pretreatment of bamboo powder (BP). In the absence of BP, segregated phases of La2O3 and Co3O4 were found. Characterization results reveal that COO- in BP performs as a complexing agent to chelate metal ions, while the −OH groups can promote the dispersion of precursors in the formed sol solution. On the other hand, chelation effect together with bio-reduction of organic carbon is in charge of large content of bulk Co2+ in LaCoO3, resulting in high amounts of oxygen vacancies that are helpful for total propane oxidation. However, Na+ and K+ species originated from BP easily lead to the formation of carbonate species on the catalyst surface, playing a negative role in propane oxidation activity. Thus, an optimum pretreatment under acid solution (pH = 1) is adopted to address the above issue. As a result, BP-1-mediated (BP pretreated under pH = 1 solution) biosynthesis of LaCoO3 exhibits a significantly high reaction rate of 3.78 μmolC3H8 g−1·s−1 at 300 °C. Moreover, the obtained catalyst delivers excellent thermal stability against 5 vol% H2O and 5 vol% CO2.

Efficient defect engineering in Co-Mn binary oxides for low-temperature propane oxidation

Cobalt-manganese composite oxides have high-activity potential for catalytic oxidation of volatile organic compounds (VOCs). However, low defect content and poor oxygen mobility of the spinel structure make it difficult to efficiently activate CH bonds of propane at low-temperature. Herein, novel amorphous Co-Mn binary oxides with enhanced defect were fabricated by a facile self-redox approach. Highly defective amorphous CoMn binary oxides with low-temperature reducibility, weak MnO bond strength and good mobility of the surface lattice oxygen remarkably improved the catalytic activity for propane oxidation. Highly defective amorphous Co1Mn3Ox catalyst showed the best catalytic activity for propane mineralization and the T90 was 207℃ under high space velocity (18 000 mL·g−1 h−1). Moreover, in situ spectroscopy technologies were utilized to explore the structure-activity relationship and the degradation mechanism of propane oxidation under real reaction condition. Significantly, as an effective defect engineering strategy, amorphous binary oxides exhibit excellent activity and can provide some enlightenments for developing efficient VOCs catalysts.

Inverse Coprecipitation Directed Porous Core–Shell Mn–Co–O Catalyst for Efficient Low Temperature Propane Oxidation

Mn–Co–O catalysts with different Mn/Co molar ratios were synthesized by means of a facile inverse coprecipitation strategy and applied for the oxidation of propane (C3H8). The XRD pattern of Co2Mn1...

The Low‐Temperature Oxidation of Propane by using H2O2 and Fe/ZSM‐5 Catalysts: Insights into the Active Site and Enhancement of Catalytic Turnover Frequencies

AbstractFe‐containing ZSM‐5 catalysts are reported to be efficient catalysts for the partial oxidation of propane to oxygenated products at reaction temperatures as low as 50 °C in an aqueous phase reaction when using the green oxidant H2O2. It was previously proposed that extra framework Fe species at the exchange sites of the zeolite are responsible for activation of both the alkane and hydrogen peroxide. Through a systematic study of the influence of framework topology and exchange properties, it is now shown that this high catalytic activity is specific to the MFI‐type Brønsted acidic zeolite ZSM‐5. Furthermore, through a simple aqueous acid washing treatment, leaching of approximately 77 % of iron present within a Fe/ZSM‐5 catalyst only caused the relative propane conversion to decrease by 17 %; implying that most of the initially loaded Fe does not actually contribute to the catalytic activity. This small change in conversion after ‘excess’ Fe removal, amounts to a three‐fold increase in turnover frequency (TOF) (Fe) from 66 h−1 to 232 h−1 compared with the parent Fe/ZSM‐5 catalyst. By comparing these samples, it is shown by NH3 temperature‐programmed desorption, 27Al magic angle spinning NMR spectroscopy, X‐ray photoelectron spectroscopy and TEM analysis that surface iron oxide species are effectively spectators in the oxidation of propane with H2O2. This provides further insight as to the location and true nature of the catalytically active Fe species.

Multiscale Informatics for Low-Temperature Propane Oxidation: Further Complexities in Studies of Complex Reactions.

The present paper describes further development of the multiscale informatics approach to kinetic model formulation of Burke et al. (Burke, M. P.; Klippenstein, S. J.; Harding, L. B. Proc. Combust. Inst. 2013, 34, 547-555) that directly incorporates elementary kinetic theories as a means to provide reliable, physics-based extrapolation of kinetic models to unexplored conditions. Here, we extend and generalize the multiscale informatics strategy to treat systems of considerable complexity-involving multiwell reactions, potentially missing reactions, nonstatistical product branching ratios, and non-Boltzmann (i.e., nonthermal) reactant distributions. The methodology is demonstrated here for a subsystem of low-temperature propane oxidation, as a representative system for low-temperature fuel oxidation. A multiscale model is assembled and informed by a wide variety of targets that include ab initio calculations of molecular properties, rate constant measurements of isolated reactions, and complex systems measurements. Active model parameters are chosen to accommodate both "parametric" and "structural" uncertainties. Theoretical parameters (e.g., barrier heights) are included as active model parameters to account for parametric uncertainties in the theoretical treatment; experimental parameters (e.g., initial temperatures) are included to account for parametric uncertainties in the physical models of the experiments. RMG software is used to assess potential structural uncertainties due to missing reactions. Additionally, branching ratios among product channels are included as active model parameters to account for structural uncertainties related to difficulties in modeling sequences of multiple chemically activated steps. The approach is demonstrated here for interpreting time-resolved measurements of OH, HO2, n-propyl, i-propyl, propene, oxetane, and methyloxirane from photolysis-initiated low-temperature oxidation of propane at pressures from 4 to 60 Torr and temperatures from 300 to 700 K. In particular, the multiscale informed model provides a consistent quantitative explanation of both ab initio calculations and time-resolved species measurements. The present results show that interpretations of OH measurements are significantly more complicated than previously thought-in addition to barrier heights for key transition states considered previously, OH profiles also depend on additional theoretical parameters for R + O2 reactions, secondary reactions, QOOH + O2 reactions, and treatment of non-Boltzmann reaction sequences. Extraction of physically rigorous information from those measurements may require more sophisticated treatment of all of those model aspects, as well as additional experimental data under more conditions, to discriminate among possible interpretations and ensure model reliability.

Low temperature propane oxidation over Co3O4 based nano-array catalysts: Ni dopant effect, reaction mechanism and structural stability

Low temperature propane oxidation has been achieved by Co3O4-based nano-array catalysts featuring low catalytic materials loading (15mg under flow rate of 150mL/min). The increased Ni doping into the Co3O4 lattice has led to 100% propane conversion at low temperature (<400°C) and has enhanced reaction kinetics by promoting the surface lattice oxygen activity. In situ DRIFTS investigations in tandem with isotopic oxygen exchange reveals that the propane oxidation proceeds via a Mars-van Krevelen mechanism where surface lattice oxygen acts as the active site whereas O2 in the reaction feed does not directly participate in CO2 formation. The Ni doping promotes the formation of less stable carbonates on the surface to facilitate the CO2 desorption. The thermal stability of Ni doped Co3O4 decreases with increased Ni concentration despite the increased catalytic activity. A balance between enhanced activity and compromised thermal stability is considered in the Ni doped Co3O4 nano-array catalysts for hydrocarbon oxidation. This study provides useful and timely guidance for rational catalyst design toward low temperature catalytic oxidation.

New Insights into Low-Temperature Oxidation of Propane from Synchrotron Photoionization Mass Spectrometry and Multiscale Informatics Modeling.

Low-temperature propane oxidation was studied at P = 4 Torr and T = 530, 600, and 670 K by time-resolved multiplexed photoionization mass spectrometry (MPIMS), which probes the reactants, intermediates, and products with isomeric selectivity using tunable synchrotron vacuum UV ionizing radiation. The oxidation is initiated by pulsed laser photolysis of oxalyl chloride, (COCl)2, at 248 nm, which rapidly generates a ∼1:1 mixture of 1-propyl (n-propyl) and 2-propyl (i-propyl) radicals via the fast Cl + propane reaction. At all three temperatures, the major stable product species is propene, formed in the propyl + O2 reactions by direct HO2 elimination from both n- and i-propyl peroxy radicals. The experimentally derived propene yields relative to the initial concentration of Cl atoms are (20 ± 4)% at 530 K, (55 ± 11)% at 600 K, and (86 ± 17)% at 670 K at a reaction time of 20 ms. The lower yield of propene at low temperature reflects substantial formation of propyl peroxy radicals, which do not completely decompose on the experimental time scale. In addition, C3H6O isomers methyloxirane, oxetane, acetone, and propanal are detected as minor products. Our measured yields of oxetane and methyloxirane, which are coproducts of OH radicals, suggest a revision of the OH formation pathways in models of low-temperature propane oxidation. The experimental results are modeled and interpreted using a multiscale informatics approach, presented in detail in a separate publication (Burke, M. P.; Goldsmith, C. F.; Klippenstein, S. J.; Welz, O.; Huang H.; Antonov I. O.; Savee J. D.; Osborn D. L.; Zádor, J.; Taatjes, C. A.; Sheps, L. Multiscale Informatics for Low-Temperature Propane Oxidation: Further Complexities in Studies of Complex Reactions. J. Phys. Chem A. 2015, DOI: 10.1021/acs.jpca.5b01003). The model predicts the time profiles and yields of the experimentally observed primary products well, and shows satisfactory agreement for products formed mostly via secondary radical-radical reactions.

Study of the low temperature oxidation of propane.

The low-temperature oxidation of propane was investigated using a jet-stirred reactor at atmospheric pressure and two methods of analysis: gas chromatography and synchrotron vacuum ultraviolet photoionization mass spectrometry (SVUV-PIMS) with direct sampling through a molecular jet. The second method allowed the identification of products, such as molecules with hydroperoxy functions, which are not stable enough to be detected by gas chromatography. Mole fractions of the reactants and reaction products were measured as a function of the temperature (530-730 K), with a particular attention to reaction products involved in the low temperature oxidation, such as cyclic ethers, aldehydes, alcohols, ketones, and hydroperoxides. A new model has been obtained from an automatically generated one, which was used as a starting point, with a large number of re-estimated thermochemical and kinetic data. The kinetic data of the most sensitive reactions, i.e., isomerizations of alkylperoxy radicals and the subsequent decompositions, have been calculated at the CBS-QB3 level of theory. The model allows a satisfactory prediction of the experimental data. A flow rate analysis has allowed highlighting the important reaction channels.

Kinetic features of the low-temperature oxidation of propane

The results from recording the chemiluminescence in the infrared part of the spectrum that emerges during the oxidation of propane in air under the effect of monotonically increasing pressure within the range 2666 Pa ≤ P ≤ 16000 Pa, both under isothermal conditions and in the 593–600 K temperature range, are presented. It is established that no pulsed chemiluminescence is observed at constant values of pressure within the range 2666 Pa ≤ P ≤ 16000 Pa and temperature within the range of 593–600 K in the reaction mixture.