Carbon Monoxide Production Research Articles

Pd-incorporated polyoxometalate catalysts for electrochemical CO2 reduction.

Polyoxometalates (POMs), representing anionic metal-oxo clusters, display diverse properties depending on their structures, constituent elements, and countercations. These characteristics position them as promising catalysts or catalyst precursors for electrochemical carbon dioxide reduction reaction (CO2RR). This study synthesized various salts-TBA+ (tetra-n-butylammonium), Cs+, Sr2+, and Ba2+-of a dipalladium-incorporated POM (Pd2, [γ-H2SiW10O36Pd2(OAc)2]4-) immobilized on a carbon support (Pd2/C). The synthesized catalysts-TBAPd2/C, CsPd2/C, SrPd2/C, and BaPd2/C-were deposited on a gas-diffusion carbon electrode, and the CO2RR performance was subsequently evaluated using a gas-diffusion flow electrolysis cell. Among the catalysts tested, BaPd2/C exhibited high selectivity toward carbon monoxide (CO) production (ca. 90%), while TBAPd2/C produced CO and hydrogen (H2) with moderate selectivity (ca. 40% for CO and ca. 60% for H2). Moreover, BaPd2/C exhibited high selectivity toward CO production over 12 h, while palladium acetate, a precursor of Pd2, showed a significant decline in CO selectivity during the CO2RR. Although both BaPd2/C and TBAPd2/C transformed into Pd nanoparticles and WO x nanospecies during the CO2RR, the influence of countercations on their product selectivity was significant. These results highlight that POMs and their countercations can effectively modulate the catalytic performance of POM-based electrocatalysts in CO2RR.

Comparison of helium and argon for the production of carbon monoxide (CO) by a plasma jet for biomedical applications

Carbon monoxide (CO) has anti-inflammatory properties and its production by plasma could be a significant advantage in the field of plasma medicine. We characterized a pulsed kHz-driven plasma jet to produce CO for biomedical applications. With no target interaction, the CO2 conversion into CO, the breakdown voltage and energy delivered to the plasma were investigated for two noble carrier gases: helium and argon. The breakdown voltage and the energy delivered to the plasma in argon gas were twice as high as in helium. The breakdown voltage was barely affected by the gas flow rate and the applied voltage, while it decreased slightly with the excitation frequency because the amount of residual charges increases with the frequency. However, the energy delivered to the plasma was not particularly affected by a change in frequency or gas flow rate, while it increased linearly with the applied voltage. CO production rose from a couple of ppm to about 2000 ppm for a specific energy input from 2 to 2000 J/L (5 × 10−4 to 5200 × 10−4 eV/(atom or molecule)), making this plasma source safe in terms of CO production for biomedical applications. Unlike literature results, the nature of the noble carrier gas did not have an impact on CO production. The CO concentration produced with 0.3% CO2 admixture increased linearly with the specific energy input (SEI) until reaching a plateau at about 2100ppm. This implies that loss processes were negligible and that CO2 dissociation was mainly due to energetic particles such as electrons and excited noble atoms. The conversion decreased with the ratio of CO2. Helium and argon as carrier gases are equivalent in terms of CO production and the CO concentration can be controlled by the SEI and the ratio of CO2.

Flame-retardant composite phase change material with silicone resin and melamine phosphate for battery thermal safety

<p>With the prosperity of electric vehicles (EVs), the thermal management of lithium-ion battery (LIB) is crucial for ensuring the safety of drivers on EVs. Composite phase change material (CPCM) with high latent heat has a great promising prospect in battery thermal management systems (BTMS). However, the thermal management efficiency of CPCM is limited due to the leakage, low thermal conductivity and flammability. Herein, the novel multifunctional CPCM with paraffin (PA), epoxy resin (ER), expanded graphite (EG), methyl MQ silicone resin (MQ) and melamine phosphate (MP) (PEE/MQ/MP3) has been prepared, which can achieve well anti-leakage, high flame-retardant and thermal conductivity, enhancing the thermal safety for battery module. The results reveal that PEE/MQ/MP3 with MQ and MP at a ratio of 1:2 can exhibit optimum flame retardant performance. The total heat release peak, smoke production rate, carbon monoxide production and carbon dioxide production are 169 MJ/m<sup>2</sup>, 0.05 m<sup>2</sup>/s, 0.005 g/s and 0.38 g/s, respectively. The battery module with PEE/MQ/MP3 displays excellent thermal management performance, delaying thermal propagation. Even after ten cycles at a 3 C rate, the maximum temperature is controlled below 50 ��C and the maximum temperature difference is maintained with 5 ��C. Besides, the thermal propagation processes of battery modules reveal that PEE/MQ/MP3 can absorb and transfer heat in the first stage timely and quickly, efficiently suppressing the thermal hazard occurrence. Therefore, this study has proposed a multifunctional flame-retardant CPCM as an effective solution to enhance the thermal safety of battery modules, thus ensuring the safety of EV drivers.</p>

Diurnal Carbon Monoxide Retrieval from FY-4B/GIIRS Using a Novel Machine Learning Method

Carbon monoxide (CO) is one of the primary reactive trace gases in the Earth’s atmosphere and plays an important role in atmospheric chemistry. The Geostationary Interferometric Infrared Sounder (GIIRS) onboard the FY-4 series satellites is currently the only geostationary hyperspectral thermal infrared sensor capable of monitoring the unprecedented hourly CO concentrations in East Asia during both daytime and nighttime. In this study, we presented a radiative transfer model-driven machine learning approach to quickly convert CO spectral features extracted from FY-4B/GIIRS into CO total columns. We built machine learning models for land and ocean regions separately from July 2022 to June 2023, and these models reproduced more than 97.77% (land) and 98.49% (ocean) of the CO column variance in the training set. We estimated the absolute uncertainty of the retrieved CO column based on error propagation theory and found that it is dominated by GIIRS measurement noise. We compared the machine learning retrieval results with optimal estimation and ground-based Fourier transform infrared measurements, and the results reveal the consistent spatial distribution and temporal variation across these different datasets. Our results confirm that the machine learning method has the potential to provide reliable CO products without the computationally intensive iterative process required by traditional retrieval methods. The diel cycle and monthly variation of CO over land and ocean demonstrate the value of GIIRS in monitoring the long-range transport of anthropogenic pollutants and biomass burning emissions.

A long-wavelength mitochondria-targeted CO fluorescent probe for living cells and zebrafish imaging.

Carbon monoxide (CO) not only causes damage to life and health as an environmental pollutant, but also undertakes many physiological functions in organisms. In particular, developing means that can be used for the determination of CO in organelles will provide insight into the vital role it plays. Studies have shown that mitochondrial respiration is closely related to CO concentrations, so it is critical to develop tools for CO detection in mitochondria. Here, we use a rhodamine derivative that can target mitochondria as fluorophores to construct a mitochondrial-labeled CO fluorescence probe (Rh-CO) with high sensitivity (detection limit: 9.4 nM), excellent water-solubility, and long emission (λem = 630 nm). Prominently, the probe has outstanding mitochondria-targeting capabilities. Moreover, we used transient glucose deprivation (TGD) and heme to stimulate endogenous CO production in living cells and zebrafish, respectively, and the probe exhibited excellent imaging capabilities. All in all, we expect this probe to contribute to a deeper understanding of the role played by CO in mitochondria.

Thermodynamic phase control of Cu-Sn alloy electrocatalysts for selective CO2 reduction.

In the electrochemical CO2 reduction reaction (CO2RR), Cu alloy electrocatalysts can control the CO2RR selectivity by modulating the intermediate binding energy. Here, we report the thermodynamic-based Cu-Sn bimetallic phase control in heterogeneous catalysts for selective CO2 conversion. Starting from the thermodynamic understanding about Cu-Sn bimetallic compounds, we established the specific processing window for Cu-Sn bimetallic phase control. To modulate the Cu-Sn bimetallic phases, we controlled the oxygen partial pressure (pO2) during the calcination of electrospun Cu and Sn ions-incorporated nanofibers (NFs). This resulted in the formation of CuO-SnO2 NFs (full oxidation), Cu-SnO2 NFs (selective reduction), Cu3Sn/CNFs, Cu41Sn11/CNFs, and Cu6Sn5/CNFs (full reduction). In the CO2RR, CuO-SnO2 NFs exhibited formate (HCOO-) production and Cu-SnO2 NFs showed carbon monoxide (CO) production with the faradaic efficiency (FE) of 65.3% at -0.99 V (vs. RHE) and 59.1% at -0.89 V (vs. RHE) respectively. Cu-rich Cu41Sn11/CNFs and Cu3Sn/CNFs enhanced the methane (CH4) production with the FE of 39.1% at -1.36 V (vs. RHE) and 34.7% at -1.50 V (vs. RHE). However, Sn-rich Cu6Sn5/CNFs produced HCOO- with the FE of 58.6% at -2.31 V (vs. RHE). This study suggests the methodology for bimetallic catalyst design and steering the CO2RR pathway by controlling the active sites of Cu-Sn alloys.

Carbon monoxide and prognosis in smokers hospitalised with acute cardiac events: a multicentre, prospective cohort study

Smoking cigarettes produces carbon monoxide (CO), which can reduce the oxygen-carrying capacity of the blood. We aimed to determine whether elevated expiratory CO levels would be associated with a worse prognosis in smokers presenting with acute cardiac events. From 7 to 22 April 2021, expiratory CO levels were measured in a prospective registry including all consecutive patients admitted for acute cardiac event in 39 centres throughout France. The primary outcome was 1-year all-cause death. Initial in-hospital major adverse cardiac events (MAE; death, resuscitated cardiac arrest and cardiogenic shock) were also analysed. The study was registered at ClinicalTrials.gov (NCT05063097). Among 1379 patients (63±15 years, 70% men), 368 (27%) were active smokers. Expiratory CO levels were significantly raised in active smokers compared to non-smokers. A CO level >11parts per million (ppm) found in 94 (25.5%) smokers was associated with a significant increase in death (14.9% for CO>11ppm vs. 2.9% for CO≤11ppm; p<0.001). Similar results were found after adjustment for comorbidities (hazard ratio [HR] [95% confidence interval (CI)]): 5.92 [2.43-14.38]) or parameters of in-hospital severity (HR 6.09, 95% CI [2.51-14.80]) and propensity score matching (HR 7.46, 95% CI [1.70-32.8]). CO>11ppm was associated with a significant increase in MAE in smokers during initial hospitalisation after adjustment for comorbidities (odds ratio [OR] 15.75, 95% CI [5.56-44.60]) or parameters of in-hospital severity (OR 10.67, 95% CI [4.06-28.04]). In the overall population, CO>11ppm but not smoking was associated with an increased rate of all-cause death (HR 4.03, 95% CI [2.33-6.98] and 1.66 [0.96-2.85] respectively). Elevated CO level is independently associated with a 6-fold increase in 1-year death and 10-fold in-hospital MAE in smokers hospitalized for acute cardiac events. Grant from Fondation Coeur & Recherche.

Electrochemical CO2-to-CO via enriched oxygen vacancies at gold/ceria interfaces

We report a strategy of catalyst design to modulate oxygen vacancies through the control of Au/ceria interface structures, promoting Au activity for carbon monoxide production in carbon dioxide electroreduction.

Integrated Capture and Electrochemical Conversion of CO2 into CO

The capture and electrochemical conversion of CO2, powered by renewable electricity, is an attractive method of sustainably producing valuable chemicals and fuels (e.g. carbon monoxide (CO)), reducing atmospheric CO2, and storing intermittent renewable energy. Integrated capture and conversion (reactive capture) of CO2 presents a CO2-to-CO electrolysis pathway that eliminates most of the upstream capital and energy costs by releasing CO2 directly inside the electrolyzer using an internal pH-swing. The reactive capture system readily allows for the collection of produced gas products via phase separation, thus minimizing downstream separation costs.Industrial-scale integration of reactive capture systems with upgrading processes require a pure and consistent product stream. Previous studies using bicarbonate electrolytes have demonstrated high selectivity towards CO. However, the limited CO2 capture capacity of bicarbonate electrolytes dilute the cathode product gas stream with excess CO2. This mandates a secondary CO2 capture unit and increases the cost of downstream separation. Other studies using carbonate or carbamate electrolyte as the inlet feed did not simultaneously achieve high CO selectivity and long-term stability.This study sought to improve the Faradaic efficiency (FE) toward CO in our carbonate electrolysis system by engineering a novel membrane electrode assembly structure. We designed a composite CO2 diffusion layer (CDL) between the cathode and the membrane that attains high CO selectivity by simultaneously achieving high alkalinity and sufficient CO2 availability at the cathode. We determined that the thickness, wettability, and permeability of the CDL affected species transport and were important optimization parameters. Applying this strategy, we produced syngas, a mixture of CO and hydrogen (H2), with an industrial H2/CO ratio of 1.16 at 200 mA cm-2. This corresponded to a CO Faradaic efficiency (FE) of 46% and energy intensity of 52 GJ tsyngas-1. The syngas produced in this system was not diluted by CO2 and contained sufficient CO content to meet industrial standards. We further increased the FE towards CO by exploring different capture solutions and designing selective catalysts for energy efficient CO production. System parameters such as temperature and pressure effects were also investigated to improve the CO2 concentration at the cathode. This study illustrated the potential for the industrial implementation of an energy efficient and capital cost effective CO2-to-CO pathway via reactive capture.

Development of Durable Large-Sized CO2 Electrolysis Cells for Industrial Applications

Utilization of carbon dioxide (CO2) as a feedstock of valuable chemicals is necessary to achieve carbon neutrality. Toshiba is developing the low-temperature zero-gap type CO2 electrolysis cells to produce carbon monoxide (CO) [1,2]. CO can further be converted into various chemicals and fuels by catalytic reactions with hydrogen. To make the CO2 electrolysis technology industrially feasible, it is necessary to establish high-throughput system by expanding the electrode area and stacking the cells. Large-sized cells and stacks often suffer from low Faradaic efficiency for the CO production, which is related to insufficient and nonuniform supply of reactant CO2 gas to the cathode reaction sites. This time we focused on the development of large-sized single cells and fabricated an electrolysis cell with 400 cm2 electrodes. With properly designed gas flow plates and gaskets, the cell voltage and the CO Faradaic efficiency of the fabricated cell at a current density of 400 mA cm-2 were comparable to those of the previously developed smaller cells with 4 cm2 electrodes. The CO concentration in the cathode outlet gas reached ca. 80% by controlling the inlet CO2 flow rate. Stability is another essential property of CO2 electrolysis cells required for the industrial application. Cathode flooding and salt precipitation are major stability issues characteristic of relatively short-term operations, whose detailed mechanism is still in debate [3]. To mitigate those stability issues, we focused on the cathode inlet humidity and the pressure difference between the cathode and the anode. The former is related to the salt concentration in electrolyte solution around the cathode reaction sites, and the latter is related to the convection of electrolyte from the anode side to the cathode side. By controlling those parameters, stable performance over 100 h was achieved.Part of this work was commissioned by Ministry of the Environment, Government of Japan.[1] Y. Kofuji, A. Ono, Y. Sugano, A. Motoshige, Y. Kudo, M. Yamagiwa, J. Tamura, S. Mikoshiba, and R. Kitagawa, Chem. Lett., 50, 482-484 (2021).[2] Y. Kiyota, Y. Kofuji, A. Ono, S. Mikoshiba, and R. Kitagawa, 242nd ECS Meeting, I05-1942 (2022).[3] M. Sassenburg, M. Kelly, S. Subramanian, W. A. Smith, and T. Burdyny, ACS Energy Lett., 8, 321-331 (2023).

The Impact of Fine Particulate Matters (PM10, PM2.5) from Incense Smokes on the Various Organ Systems: A Review of an Invisible Killer

AbstractThe drastic increase in industrialization has led to numerous adverse effects on the environment and human health. Respiratory tract disorders are one of the major emerging global health issues that lead to a high mortality rate every year. The quality of indoor and outdoor air has lowered in the last decade.The quality of indoor air has deteriorated by cooking, smoking, and burning incense sticks or smoke. The smoke released from incense and incense sticks contains gaseous products (carbon monoxide, nitrogen dioxide, and oxide of sulfur), particular matter (PM10, PM2.5), volatile organic compounds (VOCs), and polycyclic aromatic hydrocarbons (PAHs). These toxic components released from various incense sources pose a significant risk to human health and the environment. The inhalation and exposure of smoke from various incenses is hazardous to health as it inevitably culminates in deadly organ‐related diseases. With such insights, the present review article focuses on the characteristic attributes of particulate matter released from incense and other sources emphasizing healthcare and environmental concerns.

Molecular dynamics simulation of gasification technology to produce hydrogen from biomass at different initial pressures in the presence of platinum catalyst

Biomass is a renewable source of energy obtained from biological materials. Gasification technology is commonly used to produce hydrogen (H2) from biomass. This method is based on the partial oxidation of the input materials and their conversion into synthetic gas. After gasification, the biomass is converted into a gas consisting of H2, carbon monoxide (CO), carbon dioxide (CO2), and other compounds. This research investigates the number of H2 molecules (n(H2)) and CO molecules (n(CO)) in the basic structure at a temperature and pressure of 1 bar and 1800 K. Additionally, the effect of initial pressure (IP) changes on the n(H2) and n(CO) produced with a 10 % volume fraction of platinum (Pt) catalyst was evaluated using molecular dynamics (MD) simulation. The results demonstrate that the produced n(H2) and n(CO) increase from 559 to 146 to 586 and 165, increasing the Pt nanocatalyst ratio from 1 % to 10 %. Furthermore, the n(H2) and n(CO) increase from 586 to 165 to 598 and 175, respectively, by increasing the IP from 1 to 5 bar. Also, the results reveal that the combustion efficiency (CE) increases from 62 % to 66 % with increasing IP from 1 to 5 bar. The application of this research is to study the production of hydrogen and carbon monoxide from biomass using gasification technology. This information can be useful for improving the efficiency of biomass gasification for hydrogen production.

Air-Blown Biomass Gasification Process Intensification for Green Hydrogen Production: Modeling and Simulation in Aspen Plus

Hydrogen produced sustainably has the potential to be an important energy source in the short term. Biomass gasification is one of the fastest-growing technologies to produce green hydrogen. In this work, an air-blown gasification model was developed in Aspen Plus®, integrating a water–gas shift (WGS) reactor to study green hydrogen production. A sensitivity analysis was performed based on two approaches with the objective of optimizing the WGS reaction. The gasifier is optimized for carbon monoxide production (Case A) or hydrogen production (Case B). A CO2 recycling stream is approached as another intensification process. Results suggested that the Case B approach is more favorable for green hydrogen production, allowing for a 52.5% molar fraction. The introduction of CO2 as an additional gasifying agent showed a negative effect on the H2 molar fraction. A general conclusion can be drawn that the combination of a WGS reactor with an air-blown biomass gasification process allows for attaining 52.5% hydrogen content in syngas with lower steam flow rates than a pure steam gasification process. These results are relevant for the hydrogen economy because they represent reference data for further studies towards the implementation of biomass gasification projects for green hydrogen production.

Investigation of co-gasification characteristics of coal with wood biomass and rubber seals in a fixed bed gasifier

The thermochemical processing of waste in gasification to hydrogen-rich gas is considered to be a novel, promising technological option, complementing the currently employed hydrogen production methods and an effective and environment friendly way of waste utilization. The paper discusses the results of the experimental study on this novel technological option of co-gasification of coal with automotive rubber seals or wood chips in a fixed bed reactor with the application of oxygen and steam mixture as a gasification agent. The experiments were performed with the use of waste to coal blending ratio of 10:90, 15:85 and 20:80 (%w/w), and at the temperature range of 700–900 °C. The contents of carbon monoxide, carbon dioxide, hydrogen and methane in the gaseous product reported in the study were in the range of 35–36 %vol., 31–33 %vol., 29–31 %vol., and 0.10–0.16 %vol., respectively. The maximum values of the lower heating value and the total gas volume were reported for fuel blends of 10%w/w waste content at 900 °C. Hydrogen and carbon monoxide production increased with process temperature, and declined with waste fraction in a fuel blend. Gasification of fuel blends composed of coal and rubber resulted in higher hydrogen production than the gasification of coal-biomass fuel blends, which may be attributed principally to the higher fixed carbon content and higher alkali index of rubber when compared to the respective values of wood chips.

Relationship between red blood cell lifespan and endogenous carbon monoxide in the common bottlenose dolphin and beluga.

Certain deep-diving marine mammals [i.e., northern elephant seal (Mirounga angustirostris), Weddell seal (Leptonychotes weddellii)] have blood carbon monoxide (CO) levels that are comparable with those of chronic cigarette smokers. Most CO produced in humans is a byproduct of heme degradation, which is released when red blood cells (RBCs) are destroyed. Elevated CO can occur in humans when RBC lifespan decreases. The contribution of RBC turnover to CO concentrations in marine mammals is unknown. Here, we report the first RBC lifespans in two healthy marine mammal species with different diving capacities and heme stores, the shallow-diving bottlenose dolphin (Tursiops truncatus) and deep-diving beluga whale (Delphinapterus leucas), and we relate the lifespans to the levels of CO in blood and breath. The belugas, with high blood heme stores, had the longest mean RBC lifespan compared with humans and bottlenose dolphins. Both cetacean species were found to have three times higher blood CO content compared with humans. The estimated CO production rate from heme degradation indicates some marine mammals may have additional mechanisms for CO production, or delay CO removal from the body, potentially from long-duration breath-holds.NEW & NOTEWORTHY This is the first study to determine the red blood cell lifespan in a marine mammal species. High concentrations of carbon monoxide (CO) were found in the blood of bottlenose dolphins and in the blood and breath of belugas compared with healthy humans. Red blood cell turnover accounted for these high levels in bottlenose dolphins, but there may be alternative mechanisms of endogenous CO production that are contributing to the CO concentrations observed in belugas.

Mechanistic Insight into Acceptorless Dehydrogenation of Methanol to Syngas Catalyzed by MACHO-Type Ruthenium and Manganese Complexes: A DFT Study.

The acceptorless dehydrogenation of methanol to produce carbon monoxide (CO) and dihydrogen (H2) mediated by MACHO-type 1-Ru and 1-Mn complexes was theoretically investigated via density functional theory calculations. The 1-Ru-catalyzed process involves the formation of active species 4-Ru through a methanol-bridged H2 release pathway. Methanol dehydrogenation by 4-Ru yields formaldehyde and 1-Ru, followed by H2 release to regenerate 4-Ru (rate-determining step, ΔG‡ = 32.5 kcal/mol). Formaldehyde further reacts with methanol via nucleophilic attack of the MeO- ligand in the Ru complex (ΔG‡ = 9.6 kcal/mol), which is more favorable than the traditional methanol-to-formaldehyde nucleophilic attack (ΔG‡ = 33.8 kcal/mol) due to the higher nucleophilicity of MeO-. CO is ultimately produced through the methyl formate decarbonylation reaction. Accelerated H2 release in the early reaction stage compared to CO results from the initial methanol dehydrogenation and condensation of formaldehyde with methanol. In contrast, CO generation occurs later via methyl formate decarbonylation. The 1-Mn-catalyzed reaction has reduced efficiency compared to 1-Ru for the higher Gibbs energy barrier (ΔG‡ = 34.1 kcal/mol) of the rate-determining step. Excess NaOtBu promotes the reaction of CO and methanol, forming methyl formate, significantly reducing the CO/H2 ratio as the catalyst amount decreases. These findings deepen our understanding of the methanol-to-syngas transformation and can drive progress in this field.

ZnIn2S4/TiO2 photocatalyst for CO2 photoreduction: Advancing sustainable energy conversion to renewable solar fuels

The rapid increase in CO2 concentration in the atmosphere raised global climate challenges, which creates attention for the researcher to mitigate CO2 from the atmosphere so that the environment can be sustained for generations. From the photocatalysis perspective, reducing CO2 into carbon monoxide (CO) and methane (CH4) is a promising pathway for sustainable solar fuel production. Here, we fabricated a heterojunction nanocomposite photocatalyst of ZnIn2S4 and TiO2. The photocatalyst was highly efficient for CO2 reduction with 1754 and 481 μmol/g yields of CO and CH4, respectively. The photocatalyst had excellent photocatalytic activity and was stable for five consecutive experiments without significant activity loss. The potential of ZnIn2S4/TiO2 photocatalyst to revolutionize carbon monoxide production for various applications underscores its significance in advancing sustainable carbon mitigation strategies.

Heme Oxygenase-1 and Its Role in Colorectal Cancer.

Heme oxygenase-1 (HO-1) is an enzyme located at the endoplasmic reticulum, which is responsible for the degradation of cellular heme into ferrous iron, carbon monoxide and biliverdin-IXa. In addition to this main function, the enzyme is involved in many other homeostatic, toxic and cancer-related mechanisms. In this review, we first summarize the importance of HO-1 in physiology and pathophysiology with a focus on the digestive system. We then detail its structure and function, followed by a section on the regulatory mechanisms that control HO-1 expression and activity. Moreover, HO-2 as important further HO isoform is discussed, highlighting the similarities and differences with regard to HO-1. Subsequently, we describe the direct and indirect cytoprotective functions of HO-1 and its breakdown products carbon monoxide and biliverdin-IXa, but also highlight possible pro-inflammatory effects. Finally, we address the role of HO-1 in cancer with a particular focus on colorectal cancer. Here, relevant pathways and mechanisms are presented, through which HO-1 impacts tumor induction and tumor progression. These include oxidative stress and DNA damage, ferroptosis, cell cycle progression and apoptosis as well as migration, proliferation, and epithelial-mesenchymal transition.

Dealuminated Beta stabilized bimetallic PtCo nanoparticles for oxidative dehydrogenation of propane with CO2

Oxidative dehydrogenation of propane in the presence of carbon dioxide (CO2) effectively promotes the utilization of alkanes and CO2 to produce high value-added olefins and carbon monoxide products. In this work, bimetallic PtCo nanoparticles with diameter of 1–2.5 nm loaded on dealuminated nano-Beta zeolite were successfully prepared for propane oxidative dehydrogenation with CO2. The silanol groups formed after dealuminization of nano-Beta zeolite acted as the anchoring sites to enhance the dispersion of PtCo nanoparticles, and the introduction of Co further promoted the uniform distribution of Pt, resulting in smaller bimetallic PtCo nanoparticles. By optimizing the Pt/Co ratio, the conversion of propane and CO2 at 550 °C was as high as 51.8 % and 30.6 %, respectively. The dealuminized Beta supported PtCo nanoparticles exhibited high stability during the reaction, and there was no obvious aggregation of PtCo nanoparticles after 6 h on stream. In this study, the highly efficient catalyst prepared by impregnation method using modified commercial zeolite as the carrier is suitable for large-scale production and shows great practical prospect in the application of propane oxidative dehydrogenation with CO2.

Feasibility of Efficient Pyrolysis of Wood Chips and its Product Yield in Developing Countries

This paper is about the feasibility of combustibles gases like methane, ethane and carbon monoxide production from wood pyrolysis. This first laboratory experimental stage objective was to see what products can be obtained from wood pyrolysis in absence of oxygen and presence of nitrogen. The effect of temperature on the product yields was investigated. Products were characterized using gas-chromatography. We found that products of wood pyrolysis for temperatures of 700, 800, 900, 1000 and 1100°C were char, CO2 and combustibles gases like CH4, C2H2, CO and tar. NH3 was not found in the produced gases.&#x0D; In our study, condensable gases were not recovered and quantified. A gas condenser would have been necessary inserted for this purpose at the outlet of the pyrolysis reactor before routing the gases to the mass spetrograph. This study show that char production decrease from 17.08% at 700°C on the weight basis to 12.95% at 1100°C. Gases and tar production decrease, going from 82.92% at 700 °C on the weight basis to 87.05% at 1100°C. Carbone dioxide production also increase with temperature. It is the biggest part of produced gases of the wood pyrolysis gases representing an average weight proportion of 6.99% of the initial wood. Carbone monoxide yield is almost constant, around 1.6% at 800, 900 and 1000°C thought its yield at 700°C was found slightly higher accounting for 2.29% weight of the initial wood. Ethylene (C2H4) is only produced in small amount compared to others combustibles gases like methane and carbon monoxide. Its proportion which was observed almost constant, around 0.14% on the weight basis in respect to the initial wood chips weight from 700 to 900°C dropped to 0.02% at 1000°C. Methane (CH4) is produced in weight basis proportions of 2.55% which remain almost constant from 700 to 1000°C.