Presence Of Carbon Monoxide Research Articles

Carbon-Monoxide Assisted Synthesis of Cobalt-Nickel Phosphides for Hydrogen Evolution Reaction

Alkaline water electrolysis is a method for production of hydrogen as an alternative source for renewable energy. This method can be completely free of greenhouse gas emissions if it is paired with another alternative energy source, such as solar energy or wind power, to provide the necessary electricity to drive the reaction. Water electrolysis requires catalysts to make that necessary amount of electricity low enough for competitive hydrogen production in the current market. Vast numbers of studies have been performed in an attempt to fill this need for cost-effective catalysts for water electrolysis. This work focuses on the development of synthesis methods for cobalt-nickel phosphide catalysts for the hydrogen evolution reaction (HER) for water electrolysis in alkaline media. The methods for preparation of the catalysts are explored for cobalt, nickel, and cobalt-nickel alloy phosphides in the presence of carbon monoxide as a shape-controlling capping agent. Depending on the condition of carbon monoxide addition, the reaction results in high vs. low-aspect ratio nanorods or nanospheres for mono- or bimetallic cobalt-nickel phosphide nanostructures. These phosphides are then subjected to evaluation for HER via cyclic voltammetry and linear sweep voltammetry to study the effects of morphology on their HER activity. Materials characterization such as XRD, TEM, and ICP-MS are performed before the HER electrochemical evaluation for better understanding of the structure-activity relationship. The catalytic activities of these phosphides are also compared to the noble metal benchmark HER catalyst Pt/C in the same environment at their equal mass loadings. The best-performing phosphide is further tested for HER at increased mass loadings to study the effects of catalyst loadings on the mass transport and thus the activity. Further TEM characterization is performed on the most active catalyst after HER to evaluate morphological stability. It is found that in order to achieve an overpotential at the current density of 100 mA/cm2 comparable to Pt/C for 50 μg/cm2, the necessary loading for the phosphide is 250 µg/cm2.

Homopolymerization of substituted styrenes and their copolymerization with carbon monoxide catalyzed by iminopyridine palladium catalyst

Homopolymerization of styrenic monomer featuring different functional group and their copolymerization with carbon monoxide were investigated by imine-pyridine palladium complex with the assistance of AgSbF6. Poly(4-vinylbenzyl chloride) and poly(4-N,N-dimethylaminostyrene) were produced probably according to coordination-insertion mechanism. In the presence of carbon monoxide, substituted styrenes except for the 4-N,N-dimethylaminostyrene were copolymerized with CO to yield polyketones by the same catalysts. Thus, polyketones featuring chloromethyl group, diphenylaminomethyl group and quaternary ammonium salt were produced for the first time by direct alternating copolymerization. DSC results disclosed that glass transition temperature of the resulting polyketones was significantly affected by the substituents. The Tg of polyketone featuring quaternary ammonium salt was 160 °C.

Photoacoustic Heterodyne CO Sensor for Rapid Detection of CO Impurities in Hydrogen.

Hydrogen (H2) fuel cells have been developed as an environmentally benign, low-carbon, and efficient energy option in the current period of promoting low-carbon activities, which offer a compelling means to reduce carbon emissions. However, the presence of carbon monoxide (CO) impurities in H2 may potentially damage the fuel cell's anode. As a result, monitoring of the CO levels in fuel cells has become a significant area of research. In this paper, a novel photoacoustic sensor is developed based on photoacoustic heterodyne technology. The sensor combines a 4.61 μm mid-infrared quantum cascade laser with a low-noise differential photoacoustic cell. This combination enables fast, real-time online detection of CO impurity concentrations in H2. Notably, the sensor requires no wavelength locking to monitor CO online in real-time and produces a single effective signal with a period of only 15 ms. Furthermore, the sensor's performance was thoroughly evaluated in terms of detection sensitivity, linearity, and long-term stability. The minimum detection limit of 11 ppb was obtained at an optimal time constant of 1 s.

Investigation of production mechanism, structure, and formulation of Se-methyl methaneselenoate and its halogen derivatives by density functional theory (DFT)

In this study, the production mechanism of Se-methyl methaneselenoate in the presence of carbon monoxide against copper oxide nanoparticles simulation and investigated its most stable structure have been. Configurational properties of Se-methyl methaneselenoate and its halogen derivatives are evaluated and investigated using density function theory (DFT).The calculation method results of LC-WPBE/6–311 + G** show that the stereoisomerism cis form of these compounds is more stable than their trans form. IRC calculations are used to determine the path of the reaction. The frequency calculations, thermodynamic and structure parameters, force and equilibrium constants are calculated for confirm the transition state and the most stability configuration. The anomeric property and electron transfer increase with the replacement of halogen instead of 5H. The highest amount of E(2)/kcal.mol−1 is for [Lp(2) O1 → π*(C2-Se3)] of cis form, in its halogenated compounds, it increases with the reduction in the electronegativity and increasing in the atomic radius of the halogen.

New ruthenium/phosphino carbazole systems for selective preparation of alcohols under hydroformylation conditions

Efficient hydrogenation of aldehydes is highly desirable in hydroformylation process to obtain alcohol products. This work developed carbazole-derived phosphine ligands for efficient Ru-catalyzed hydrogenation of aldehydes in the presence of carbon monoxide. Up to 99 % yields of alcohols were obtained in the presence of high-pressure CO at 130 ℃. The results of different ligands revealed the crucial role of NH moiety on carbazole in promoting the catalytic hydrogenation. It was applied to the Co/Ru-catalyzed hydroformylation process, resulting in the production of long-chain alcohols with excellent yields.

Causes, Impacts and Policy Implications of Carbon Monoxide Air Pollution in Third World Countries

Globally, countries are grappling with significant complications, notably air pollution and global warming. One of the hazardous substances contributing to this problem is carbon monoxide (CO), a deadly, odorless, and colorless gas released through both natural processes and human activities. Among developing nations, Guatemala has experienced rapid and dramatic urbanization over the last decades. As a result of this urbanization, a disturbing correlation exists between increased respiratory disease cases and the presence of carbon monoxide in the air. Guatemalans face a surplus of health issues due to air pollution, including asthma, upper respiratory disorders, and chronic obstructive pulmonary disease (COPD). These health risks are not solely confined to urbanized areas but also extend into rural regions where Guatemalans use open fires inside their homes for cooking.
 Unfortunately, current laws governing air quality oversight and management in Guatemala are inadequate as they fail to safeguard and benefit the well-being of their people. To assess the extent of air pollution in Guatemala, the study measured carbon monoxide levels in parts per million (ppm) using EasyLog USB at various locations and Guatemala City, the nation's most populous urban city. Data was collected over six days, revealing alarmingly high levels of CO, specifically in densely populated areas with significant vehicular activity. The lack of proper ventilation systems and environmental regulations in these areas contributes to the persistence of elevated CO levels. This study's primary objective is to highlight CO poisoning issues in developing countries like Guatemala, emphasizing the urgent need for the national government to implement appropriate legislation and monitoring systems to mitigate its adverse effects. By taking decisive action, Guatemala can further reduce and protect its people from the detrimental impact of air pollution and ultimately work towards creating a healthier, more sustainable environment.

Performance studies of Pt, Pd and PtPd supported on SBA-15 for wet CO and hydrocarbon oxidation

Climate change is one of the most pressing issues confronting modern society due to the greenhouse gas emissions. Reducing anthropogenic greenhouse gas emissions is critical to preventing further global warming. This work explores the oxidation of methane, propane and ethylene in the presence of carbon monoxide (CO) and water vapors over Pt and Pd mono and bimetallic catalysts supported on SBA-15. Pt and Pd catalysts with uniform distribution are prepared on high surface area SBA-15 support using different precursors and solvents. The performance of catalysts is evaluated as a function of temperature and time. The inhibitory effect of water vapors and co-feeding of carbon monoxide is studied on the light-off temperature and stability of Pt, Pd and bimetallic catalysts. We performed in-depth characterization using XRD, BET, XPS, TEM, CO chemisorption and ICP-OES techniques to correlate the properties of catalysts with oxidation results. In terms of their oxidation activity, Pd exhibited higher activity towards alkanes (methane and propane) at low temperatures, while Pt is more active for ethylene. Carbon monoxide undergoes oxidation at the lowest temperature over both Pt and Pd, followed by the oxidation of all other components in the feed. It is confirmed that PdO remains highly active when reductants are only alkanes. However, the coexistence of M/MOx ionic species (Pt0, Pt2+, Pd0, Pd2+) appears be to more active when mixed feed is used. Optimal alloying compositions have the potential to minimize the decrease in conversion activity in the presence of CO and water vapors. This work is expected to advance the rational synthesis and application of multicomponent and multifunctional catalytic materials.

Physical-chemical processes at Mo-doped ceria-yttria stabilized zirconia (YSZ) anodes in solid oxide fuel cells using syngas derived by the distribution of relaxation times method

The use of environment-friendly carbonaceous fuels (such as, biomass and synthetic fuels) to produce electricity using solid oxide fuel cells (SOFCs) has emerged as a promising alternative to the use of high-purity hydrogen, which remains as a difficult to produce and store gas. Much effort has been put in the development of SOFC anodes highly active and stable for the use of carbonaceous fuels, such as ceria-based materials, but only recently research has focused on the comprehensive analysis of the interfacial physical-chemical processes affecting their performance.This work presents an in-depth analysis of the interfacial processes occurring at a Mo-doped ceria-yttria stabilized zirconia (YSZ) cermet anode in a SOFC using humidified syngas as fuel. To this end, electrochemical impedance spectroscopy (EIS) data is generated and analysed by the distribution of relaxation times (DRT) method. In addition, gas chromatography analysis of the internal reforming products generated under open circuit voltage (OCV) conditions and post-mortem analysis of the electrode materials after polarization are discussed in support of the DRT results.It is observed that the presence of carbon monoxide (CO) in fuel, as compared to pure hydrogen, influences the anodic charge transfer processes not only due to promotion of the water-gas-shift reaction at the anode two-phase (fuel | electrode) and three-phase (fuel | electrode | electrolyte) interfaces, but also because of its direct electrooxidation at the anode three-phase interfaces. The electrooxidation of carbon monoxide presents a slightly higher activation energy than the electrooxidation of hydrogen (ca. 1.86 and 1.21 eV, respectively), which explains the slower kinetics of SOFCs when using syngas as fuel. Additionally, other oxidation processes of CO at the anode interfaces (such as, the Boudouard reaction) promote the formation of carbon deposits lacking ordered structure, which are more reactive than graphitic structures formed at Ni-YSZ anodes but still can negatively influence the electrochemical kinetics.

Copper-catalyzed visible-light-induced ring-opening carbonylation of sulfonium salts

Herein, we developed a direct and effective strategy for the synthesis of sulfur-containing carboxylic acid derivatives through copper/visible light catalyzed ring-opening carbonylation of sulfonium salts. The protocol employs photoredox to promote the selective cleavage of sulfonium salts C(sp3)-S bond, while performing sequential functionalization to form vicinal C–C and C-X (X = O or N) bonds in the presence of carbon monoxide and nucleophiles. A variety of substrates were successfully transformed into the desired carbonylated products in moderate to good yields with good functional group tolerance and excellent chemoselectivity. Importantly, this approach can be easily extended to late-stage modification of bioactive molecules.

Selective Oxidation of Methane to Methanol over Au/H-MOR.

Selective oxidation of methane to methanol by dioxygen (O2) is an appealing route for upgrading abundant methane resource and represents one of the most challenging reactions in chemistry due to the overwhelmingly higher reactivity of the product (methanol) versus the reactant (methane). Here, we report that gold nanoparticles dispersed on mordenite efficiently catalyze the selective oxidation of methane to methanol by molecular oxygen in aqueous medium in the presence of carbon monoxide. The methanol productivity reaches 1300 μmol gcat-1 h-1 or 280 mmol gAu-1 h-1 with 75% selectivity at 150 °C, outperforming most catalysts reported under comparable conditions. Both hydroxyl radicals and hydroperoxide species participate in the activation and conversion of methane, while it is shown that the lower affinity of methanol on gold mainly accounts for higher methanol selectivity.

Critical analysis of variable atmosphere gaseous reduction of iron oxides pellets

ABSTRACT The paper deals with the analyses of the direct reduction kinetics of industrial iron oxide pellets. Various types of pellets were reduced at different temperatures and pressure (700–1100°C and 1–6 bar) in various atmospheres with different contents of hydrogen and carbon monoxide. The reduction behaviour was described in terms of time to reduction, rate of reduction, and kinetics constant. For those pellets reduced in presence of carbon monoxide, also the carbon percentage in the reduced pellets was taken into account. All the obtained results were analysed through the employment of a commercial multi-objective optimisation tool (modeFrontier) in order to precisely define the weight that each single parameter has on the reduction behaviour of the pellets. The performed analyses allowed also to correlate the different processing parameters and the pellets properties in order to define the kinetics conditions as well as the factors limiting the reduction process.

Experimental investigation on the impact of cable fire products from flame-retardant cables on catalysts used in passive auto-catalytic recombiners

Cable fires in nuclear power plants have a significant probability to occur at any time in the course of a severe accident or may as well be the initiating event of a severe accident sequence. During the combustion process, enormous amounts of aerosols alongside specific combustion gases (e.g. CO, CO2) can be released. Both nature and amount of the cable fire products depend on the combustion conditions. The effect of cable fire products distributing inside the containment and getting in contact with the catalyst surfaces of passive auto-catalytic recombiners (PARs) is of vital interest for safety analyses, in order to assess the hydrogen mitigation efficiency under these conditions.The newly built REKO-Fire facility at Forschungszentrum Jülich combines a flow tube reactor for catalyst investigation with a steady-state tube furnace for the constant generation of cable fire products at varying combustion conditions. That way, simultaneous exposure of 5 × 5 cm2 catalyst samples to cable fire products and hydrogen/air mixtures is possible, enabling to quantify the influence of gaseous and particulate components on the catalysts’ start-up behavior. The installation has been used in the present study to investigate the effect of cable fire products obtained from flame-retardant power cables under three different fire conditions on the start-up of two types of catalysts for hydrogen recombination.For well-ventilated cable fire, neither gaseous nor particulate (mainly soot) cable fire products seem to affect the onset of the catalytic H2 conversion for both Pt and Pd-based catalysts. In under-ventilated fire conditions, the Pt-based catalyst is significantly deactivated, while the only impairment for the Pd-based catalyst is observed at very low hydrogen concentrations. For cable fire products generated from oxidative pyrolysis, the overall picture is ambiguous. On the one side it is obvious that deactivation and start-up delay occur for both catalyst types. However, no clear conclusion can be taken from the experimental data concerning the effect of exposure time. The presence of carbon monoxide in the atmosphere as well as particulate depositions from cable pyrolysis seem to be the most relevant mechanisms for catalyst deactivation and deserve further investigation.

Effect of cobalt incorporation on the stability of ionic Pd in the presence of carbon monoxide over Pd/BEA passive NOx adsorbers

Bimetallic PdCo/BEA zeolites were evaluated for the first time as potential passive NOx adsorbers (PNAs) in the presence of carbon monoxide (CO). The NOx:Pd ratio of Pd/BEA and PdCo/BEA catalysts decreased during 5 consecutive NOx + CO adsorption/desorption cycles due to loss of ionic Pd. The amount of NOx desorbed at T < 200 °C (weakly adsorbed NOx) was slightly increased over monometallic Pd/BEA, while the amount of NOx desorbed at T > 200 °C (strongly adsorbed NOx) was continuously decreased during 5 consecutive NOx + CO adsorption/desorption cycles. This behavior can be attributed to a decrease in the Pd2+ adsorption sites through formation of PdO. Specifically, part of Pd2+ can be reduced to Pd0 in the presence of CO and Pd0 can be further oxidized to PdO during oxidative pretreatments. Unlike Pd/BEA, the amount of weakly adsorbed NOx was decreased and the amount of strongly adsorbed NOx was amplified over bimetallic PdCo/BEA PNAs. Microscopic images, O2-temperature programmed desorption, and H2-temperature programmed reduction experiments over Pd/BEA and PdCo/BEA after cycling showed that Co incorporation in Pd/BEA zeolites suppressed PdO formation in the presence of CO. These results demonstrated that Co incorporation in Pd/BEA zeolites can stabilize the Pd2+ adsorption sites, thus provide higher amount of NOx desorption at temperatures > 200 °C. In situ diffuse reflectance infrared spectroscopy experiments showed that the amount of Pd2+ decreased upon Co incorporation, while the adsorbed NOx species remained unaltered. Density functional theory calculations found that Co experienced a direct bonding interaction with Pd, providing overall stability.

The comparative evaluation of the criteria used to determine the critical values of the partial density of carbon monoxide as part of the calculation of time to the blocking of escape routes in case of a room fire

Introduction. Critical values of the partial density of gas, the toxic dose or relative mass of carboxyhemoglobin in human blood serve as the criteria determining the time to the blocking of escape routes due to the presence of carbon monoxide. However, the comparative analysis of the effect produced by the selected criterion on the time to the blocking of escape routes due to the presence of this gas has not been conducted yet.Goals and objectives. The purpose of the article is to compare the values of the time to the blocking of escape routes by carbon monoxide obtained using various methods of determining the critical values of the carbon monoxide density. Towards this end, experimental studies on combustion processes of various solid and liquid combustible substances and materials were conducted in a small-scale test unit, and calculations of the time to the blocking of escape routes with carbon monoxide were made on their basis.Theoretical fundamentals. The amount of carbon monoxide, inhaled during a fire, is calculated using experimentally measured partial densities of CO and mathematical models designated for the calculation of the toxic dose of this gas and formation of carboxyhemoglobin in human blood.Results and discussion. Experimental dependencies between the testing time and medium-volume densities of monoxide emitted during the combustion of the “low smoke” PVC cable sheathing, timber (pinewood), chocolate, transformer oil and vegetable oil are presented. The authors obtained theoretical dependencies between the toxic dose and mass concentration of carboxyhemoglobin in human blood, on the one hand, and the time for the combustible materials, analyzed in the article. It has been found that the values of time to the blocking of escape routes due to the presence of carbon monoxide may differ significantly depending on the method used to determine the critical values of the carbon monoxide density.Conclusions. Standard methods, used to calculate the time to the blocking of escape routes due to the presence of carbon monoxide, employ the value of the critical partial density which may involve a substantial overestimation of the above time frame and the underestimation of the toxic effect produced on a person in the process of his/her evacuation. Therefore, it is necessary to apply all methods, discussed in the article, to select the minimum value of the above time frame.

Selective Catalytic Oxidation of Methane to Methanol in Aqueous Medium over Copper Cations Promoted by Atomically Dispersed Rhodium on TiO2

AbstractDirect conversion of methane into value‐added chemicals, such as methanol under mild conditions, is a promising route for industrial applications. In this work, atomically dispersed Rh on TiO2 suspended in an aqueous solution was used for the oxidation of methane to methanol. Promoted by copper cations (as co‐catalyst) in solution, the catalysts exhibited high activity and selectivity for the production of methanol using molecular oxygen with the presence of carbon monoxide at 150 °C with a reaction pressure of 31 bar. Millimole level yields of methanol were reached with the selectivity higher than 99 % using the Rh/TiO2 catalysts with the promotion of the copper cation. CO was the reductive agent to generate H2 from H2O, which led to the formation of H2O2 through the reaction of H2 and O2. Atomically dispersed Rh activated the C−H bond in CH4 and catalyzed the oxidation using H2O2. Copper cations maintained the low‐valence state of Rh. Moreover, copper acted as a scavenger for suppressing the overoxidation, thus leading to the high selectivity of methanol.

Selective Catalytic Oxidation of Methane to Methanol in Aqueous Medium over Copper Cations Promoted by Atomically Dispersed Rhodium on TiO2.

Direct conversion of methane into value-added chemicals, such as methanol under mild conditions, is a promising route for industrial applications. In this work, atomically dispersed Rh on TiO2 suspended in an aqueous solution was used for the oxidation of methane to methanol. Promoted by copper cations (as co-catalyst) in solution, the catalysts exhibited high activity and selectivity for the production of methanol using molecular oxygen with the presence of carbon monoxide at 150 °C with a reaction pressure of 31 bar. Millimole level yields of methanol were reached with the selectivity higher than 99 % using the Rh/TiO2 catalysts with the promotion of the copper cation. CO was the reductive agent to generate H2 from H2 O, which led to the formation of H2 O2 through the reaction of H2 and O2 . Atomically dispersed Rh activated the C-H bond in CH4 and catalyzed the oxidation using H2 O2 . Copper cations maintained the low-valence state of Rh. Moreover, copper acted as a scavenger for suppressing the overoxidation, thus leading to the high selectivity of methanol.

Comparison study of preferential oxidation of CO over nanocrystalline Cu/CeO2 catalysts synthesized by different preparation methods

Preferential oxidation of carbon monoxide in presence of excess hydrogen is a promising alternative to restrict the CO deposition in the Pt-anode in the practical polymer electrolyte membrane fuel cell application. In the present work, nanocrystalline copper-ceria catalysts have been synthesized by hydrothermal method, wet impregnation method and urea nitrate combustion method. Their characterizations have been carried out by using X-ray diffraction, transmission electron microscopy, X-ray photoelectron spectroscopy . It has been found that Cu 2+ replaced Ce 4+ in cerium oxide, creating oxygen vacancy. The formation of more nano-sized CeO 2 leads to more oxygen vacancies in CeO 2 through the formation of interfacial Cu 1+ ions, which also enhances the CO oxidation activity. Among the synthesized Cu-CeO 2 catalysts, the catalyst prepared by hydrothermal method have shown both CO conversion and CO 2 selectivity as 100% towards CO oxidation at 373 K in the presence of excess H 2 making this catalyst viable for practical fuel cell application.

Direct Synthesis of Formic Acid from Carbon Dioxide by Hydrogenation Over Ruthenium Metal Doped Titanium Dioxide Nanoparticles in Functionalized Ionic Liquid

Background: Presently worldwide manufacturing of formic acid follows the permutation of methanol and carbon monoxide in presence of a strong base. But due to the use of toxic CO molecule and easy availability of CO2 molecule in the atmosphere, most of the research has been shifted from the conventional method of formic acid synthesis to direct hydrogenation of CO2 gas using different homogenous and heterogeneous catalysts. Objective: To develop reaction protocol to achieve easy CO2 hydrogenation to formic acid using Ionic liquid reaction medium. Methods: We used the sol-gel method followed by calcination (over 250oC for 5 hours) to synthesize two types of ruthenium metal-doped TiO2 nanoparticles (with and without ionic liquids), namely Ru@TiO2@IL and Ru@TiO2. We are reporting the application NR2 (R= CH3) containing imidazolium- based ionic liquids not only to achieve a good reaction rate but also to get agglomeration free ruthenium metal-doped TiO2 nanoparticles along with easy product isolation due to the presence of NR2 (R= CH3) functionality in ionic liquid structure. We synthesized various NR2 (R= CH3) functionalized ionic liquids such as 1-Butyl-3-methylimidazolium Chloride, 1,3-di(N,Ndimethylaminoethyl)- 2-methylimidazolium trifluoromethanesulfonate ([DAMI][TfO]), 1,3-di(N,Ndimethylaminoethyl)- 2-methylimidazolium bis (trifluoromethylsulfonyl) imide ([DAMI][NTf2]) and 1-butyl-3-methylimidazolium chloride ionic liquids which were synthesized as per the reported procedure. Results: We easily developed two types of Ru metal-doped TiO2 nanoparticles using the sol-gel method. After calcination, both Ru@TiO2@IL (3.2 wt% Ru), and Ru@TiO2 (1.7 wt% Ru) materials were characterized by XRD, FTIR, TEM, ICP-AES, EDS, and XANES analysis. After understanding the correct structural arrangement of Ru metal over TiO2 support, we utilized both Ru@TiO2@IL (3.2 wt% Ru) and Ru@TiO2 (1.7 wt% Ru) the materials as a catalyst for direct hydrogenation of CO2 in the presence of water and functionalized [DAMI] [TfO] ionic liquid. Conclusion: Here we demonstrated the preparation and characterization of TiO2 supported Ru nanoparticles with and without ionic liquid. After understanding the correct morphology and physiochemical analysis of Ru@TiO2@IL (3.2 wt% Ru), and Ru@TiO2 (1.7 wt% Ru) catalysts, we examined their application in CO2 reduction and formic acid synthesis. During the optimization, we also noticed the significant effect of functionalized [DAMI] [TfO] ionic liquid and water to improve the formic acid yield. Lastly, we also checked the stability of the catalyst by recycling the same till the 7th run.

Simultaneous H/D and 13C/12C Anomalous Kinetic Isotope Effects during the Sonolysis of Water in the Presence of Carbon Monoxide.

Splitting of water molecules driven by ultrasound plays a central role in sonochemistry. While studies of sonoluminescence revealed the formation of a plasma inside the cavitation bubble, much less is known about the contribution of plasma chemical processes to the sonochemical mechanisms. Herein, we report for the first time sonochemical processes in water saturated with pure CO. The presence of CO causes a large increase in the H/D kinetic isotope effect (KIE) to αH = 14.6 ± 1.8 in a 10% H2O/D2O mixture under 20 kHz ultrasound. The anomalous H/D KIE is attributed to electron quantum tunneling in the plasma produced by cavitation. In addition, CO2 formed simultaneously with hydrogen during the sonochemical process is enriched with the 13C isotope, which indicates a V-V pumping mechanism typical for non-equilibrium plasma. Both observed KIEs unambiguously point to the contribution of quantum effects in sonochemical mechanisms.

Identifikasi Karbon Monoksida Dalam Darah Pada Penjual Buah Di Jembatan Kembar Sungguminasa

The chemical compound of CO gas is a gas that has no color and contributes greatly to environmental pollution as a result of incomplete combustion of fuel produced from motor vehicles. Carbon monoxide is very dangerous (toxic, so it is often referred to as the "silent killer". The presence of CO gas will be very dangerous if inhaled by humans because the gas will replace the position of oxygen that binds to hemoglobin in the blood. The purpose of the study was to identify the presence or absence of carbon monoxide (CO) in the blood of fruit sellers at the Sungguminasa Twin Bridge. This research is an analytical observational field research using the alkaline dilution test method. The sampling technique used purposive sampling with the criteria of working more than one year, working 8 hours a day and not smoking. The number of samples used as many as 9 samples of venous blood. From the results of this study, it can be concluded that the presence of carbon monoxide gas was not identified in all blood samples of fruit sellers at the Sungguminasa Twin Bridge. This is because in the alkaline dilution test method, CO gas can only be identified with saturation levels above 20%.