Reduction Of Carbon Monoxide Research Articles

Homogeneous Electrocatalytic Reduction of CO2 by a CrN3O Complex: Electronic Coupling with a Redox-Active Terpyridine Fragment Favors Selectivity for CO.

Electrocatalyst design and optimization strategies continue to be an active area of research interest for the applied use of renewable energy resources. The electrocatalytic conversion of carbon dioxide (CO2) is an attractive approach in this context because of the added potential benefit of addressing its rising atmospheric concentrations. In previous experimental and computational studies, we have described the mechanism of the first molecular Cr complex capable of electrocatalytically reducing CO2 to carbon monoxide (CO) in the presence of an added proton donor, which contained a redox-active 2,2'-bipyridine (bpy) fragment, CrN2O2. The high selectivity for CO in the bpy-based system was dependent on a delocalized CrII(bpy•-) active state. Subsequently, we became interested in exploring how expanding the polypyridyl ligand core would impact the selectivity and activity during electrocatalytic CO2 reduction. Here, we report a new CrN3O catalyst, Cr(tpytbupho)Cl2 (1), where 2-(2,2':6',2″-terpyridin-6-yl)-4,6-di-tert-butylphenolate = [tpytbupho]-, which reduces CO2 to CO with almost quantitative selectivity via a different mechanism than our previously reported Cr(tbudhbpy)Cl(H2O) catalyst. Computational analyses indicate that, although the stoichiometry of both reactions is identical, changes in the observed rate law are the combined result of a decrease in the intrinsic ligand charge (L3X vs L2X2) and an increase in the ligand redox activity, which result in increased electronic coupling between the doubly reduced tpy fragment of the ligand and the CrII center. The strong electronic coupling enhances the rate of protonation and subsequent C-OH bond cleavage, resulting in CO2 binding becoming the rate-determining step, which is an uncommon mechanism during protic CO2 reduction.

Melamine tannin nanosheet loading on black phosphorus towards enhancing its thermal safety, catalytic smoke and toxicity suppression performances

Black phosphorus (BP) was limited in practical application due to its instability in the air and low compatibility with polymers. In addition, the lack of smoke suppression of BP made it difficult to reduce the harm of smoke and toxic gas in fire. The functional BP nanosheets (BP-TA@MA-Co) were prepared by combining the smoke suppression mechanism of cobalt ions with the oxidation resistance mechanism of melamine tannin nanosheets. Excellent fire safety was clearly demonstrated by the effective combination of BP-TA@MA-Co and epoxy (EP), with 63.5% reduction in total heat release (THR), 18.1% reduction in total smoke production (TSP) and 19.5% reduction in total carbon monoxide. Therefore, this study provided a feasible solution for loading high-valence metal compounds on the surface of BP and a unique thinking for the preparation of EP composites with high comprehensive performances.

Classification and Prediction of Nitrogen Dioxide in a Portuguese Air Quality Critical Zone

This study presents classification and prediction exercises to evaluate the future behavior of nitrogen dioxide in a critical air quality zone located in Portugal using a dataset, the time span of which covers the period between 1 September 2021 and 23 July 2022. Three main results substantiate the importance of this research. First, the classification analysis corroborates the idea of a neutrality principle of road traffic on the target since the respective coefficient is significant, but quantitatively close to zero. This result, which may be the first sign of a paradigm shift regarding the adoption of electric vehicles in addition to reflect the success of previously implemented measures in the city of Lisbon, is reinforced by evidence that the carbon monoxide emitted mostly by diesel vehicles exhibits a significant, negative and permanent effect on satisfying the hourly limit value associated with the target. Second, robustness checks confirm that the period between 8 h and 16 h is particularly remarkable for influencing the target. Finally, the predictive exercise demonstrates that the internationally patented Variable Split Convolutional Attention model has the best predictive performance among several deep learning neural network alternatives. Results indicate that the concentration of nitrogen dioxide is expected to be volatile and only a redundant downward trend is likely to be observed. Therefore, in terms of policy recommendations, additional measures to avoid exceeding the legal nitrogen dioxide ceiling at the local level should be focused on reducing carbon monoxide emissions, rather than just being concerned about halting the intensity of road traffic.

Thermal efficiency improvement and emission reduction potential by adopting improved biomass cookstoves for sauce-cooking process in rural Ethiopia

Sauce (“Wot”) preparation and Injera baking using an open-fire stove are recurrent cooking activities in rural households in Ethiopia. The low thermal efficiency open-fire stove utilized huge quantities of fuel and caused high particulate matter exposure for cookers. A rocket stove is proposed and fabricated that burns commonly used biomass fuel. The Aprovecho Research Center design guiding principles were followed to develop the prototype. The overall performance of the model was tested using a water boiling test (WBT version 4.2.3) to confirm thermal efficiency improvement and air pollutant reduction compared to the conventional stove. Indoor air pollution (IAP) measuring apparatus was installed to record the carbon monoxide (CO) and fine particulate matter (PM 2.5 ) emission exposure of the cooker during the WBT test. The performance testing result of the model has shown an improved thermal efficiency of 32% compared to the three-stone stove (14%). The stove reduced CO concentration by 42% and PM 2.5 concentration by 99.5% over the three-stone stove. The average concentration exposure for an hour (3.1 μg/m 3 CO) of the new stove satisfies the World Health Organization indoor air quality standard. Furthermore, the stove showed a 43% reduction in specific fuel consumption (roughly 625 kg fuel saving/year/device). The fuel-saving achieved from the model resulted in the reduction of CO 2 gas emissions by 1.3 tCO 2 /year. Therefore, it is assumed that the rocket stove has a considerable improvement over the open-fire stove and its timely development may enhance environmental care. Therefore, shifting the cooking technology from the conventional traditional cooking stove to rocket stoves could mitigate indoor air pollutant emissions and deforestation. • A rocket stove was fabricated and tested in a water boiling test. • The average thermal efficiency of the stove was found to be 32%. • The stove reduced CO concentration by 42% over the three-stone stove. • The stove reduced specific fuel consumption by 43% as compared to open fire stove. • The CO 2 emission saving of the stove was found to be 1.3 tCO 2 /year.

Toward abiotic sugar synthesis from CO2 electrolysis

Toward abiotic sugar synthesis from CO2 electrolysis

Relation of Pulmonary Diffusing Capacity Decline to HRCT and VQ SPECT/CT Findings at Early Follow-Up after COVID-19: A Prospective Cohort Study (The SECURe Study).

A large proportion of patients exhibit persistently reduced pulmonary diffusion capacity after COVID-19. It is unknown whether this is due to a post-COVID restrictive lung disease and/or pulmonary vascular disease. The aim of the current study was to investigate the association between initial COVID-19 severity and haemoglobin-corrected diffusion capacity to carbon monoxide (DLco) reduction at follow-up. Furthermore, to analyse if DLco reduction could be linked to pulmonary fibrosis (PF) and/or thromboembolic disease within the first months after the illness, a total of 67 patients diagnosed with COVID-19 from March to December 2020 were included across three severity groups: 12 not admitted to hospital (Group I), 40 admitted to hospital without intensive care unit (ICU) admission (Group II), and 15 admitted to hospital with ICU admission (Group III). At first follow-up, 5 months post SARS-CoV-2 positive testing/4 months after discharge, lung function testing, including DLco, high-resolution CT chest scan (HRCT) and ventilation-perfusion (VQ) single photon emission computed tomography (SPECT)/CT were conducted. DLco was reduced in 42% of the patients; the prevalence and extent depended on the clinical severity group and was typically observed as part of a restrictive pattern with reduced total lung capacity. Reduced DLco was associated with the extent of ground-glass opacification and signs of PF on HRCT, but not with mismatched perfusion defects on VQ SPECT/CT. The severity-dependent decline in DLco observed early after COVID-19 appears to be caused by restrictive and not pulmonary vascular disease.

Experimental and parametric studies on the effect of waste cooking oil methyl ester with diesel fuel in compression ignition engine

Diesel engine discharge characteristics are primarily influenced by fuel qualities, combustion chamber type, and injection settings. This study used combinations of biodiesel, waste cooking oil, and diesel fuel to do a parametric investigation on a diesel engine (DF80-WCOB20, DF70-WCOB30, DF60-WCOB40, and DF50-WCOB50). Using a complete factorial design L75 orthogonal array (O.A.), the experimental and parametric investigations were carried out. According to the experimental findings, DF80-WCOB20, DF70-WCOB30, DF60-WCOB40, and DF50-WCOB50 increase specific energy consumption while reducing engine efficiency, carbon monoxide emissions, and hydrocarbon discharges. At all engine loads, DF80-WCOB20′s brake thermal efficiency (BTE) was higher than that of DF70-WCOB30, DF60-WCOB40, and DF50-WCOB50 for respective compression ratios of 16.5, 17.5, and 18.5. Additionally, the BSFC for C.R. increases (16.5, 17.5, and 18.5) at all engine loads when waste cooking oil biodiesel is mixed with diesel fuel compared to diesel fuel. The findings indicate that while adding biodiesel made from used cooking oil to diesel fuel greatly reduces carbon monoxide and hydrocarbon emissions, it also results in higher nitrogen oxide emissions than diesel fuel.

Enhancing acetate selectivity by coupling anodic oxidation to carbon monoxide electroreduction

Electrocatalytic conversion of carbon monoxide (CO) is being actively developed as a key component for tandem CO2 electrolysis. Great effort has been devoted to engineering CO reduction electrocatalysts for better multicarbon product selectivity. However, less work has focused on other performance parameters that are crucial for commercializing CO electrolysis, such as liquid product concentration and purity. Here, we present an internally coupled purification strategy to substantially improve the acetate concentration and purity in CO electrolysis. This strategy utilizes an alkaline-stable anion exchange membrane with high ethanol permeability and a selective ethanol partial oxidation anode to control the CO reduction product stream. We demonstrate stable 120-h continuous operation of the CO electrolyser at a current density of 200 mA cm−2 and a full-cell potential of <2.3 V, continuously producing a 1.9 M acetate product stream with a purity of 97.7%. The acetate stream was further improved to a concentration of 7.6 M at >99% purity by tuning the reaction conditions. Finally, a techno-economic analysis shows that a highly concentrated liquid product stream is essential to reduce the energy consumption of product separation.

Role of green finance policy in renewable energy deployment for carbon neutrality: Evidence from China

Carbon emission is not just a threat to the environment but also an economic burden. Faced with the growing pollutant emission, the purpose of financial institutions is more crucial. To address this issue, this research employs difference-in-differences to assess the role of China's green financing policy in renewable energy deployment for emission reduction. The findings demonstrate that the green finance strategy in renewable energy can reduce the general situation of emission reduction. The results show that the policy was effective in lower three contaminants, including Sulfur dioxide, Nitrogen dioxides, and PM2.5, but are inadequate in reducing Carbon monoxide, Ozone, and PM10. Besides, the control impacts of green finance policy are via local enterprises' economic activities. Compared with the financially advanced areas, the reducing emissions impacts of green financing policies in the financially undeveloped areas are greater. These results give recommendations for controlling air quality financial advantage from the standpoint of micro practice.

Study on Emission Characteristics and Emission Reduction Effect for Construction Machinery under Actual Operating Conditions Using a Portable Emission Measurement System (Pems).

With the acceleration of urban construction, the pollutant emission of non-road mobile machinery such as construction machinery is becoming more and more prominent. In this paper, a portable emissions measurement system (PEMS) tested the emissions of eight different types of construction machinery under actual operating conditions and was used for idling, walking, and working under the different emission reduction techniques. The results showed that the pollutant emission of construction machinery is affected by the pollutant contribution of working conditions. According to different emission reduction techniques, the diesel oxidation catalyst (DOC) can reduce carbon monoxide (CO) by 41.6–94.8% and hydrocarbon (HC) by 92.7–95.1%, catalytic diesel particulate filter (CDPF) can reduce particulate matter (PM) by 87.1–99.5%, and selective catalytic reduction (SCR) using urea as a reducing agent can reduce nitrogen oxides (NOx) by 60.3% to 80.5%. Copper-based SCR is better than vanadium-based SCR in NOx reduction. In addition, the study found that when the enhanced 3DOC + CDPF emission reduction technique is used on forklifts, DOC has a “low-temperature saturation effect”, which will reduce the emission reduction effect of CO and THC. The use of Burner + DOC + CDPF emission reduction techniques and fuel injection heating process will increase CO’s emission factors by 3.2–3.5 and 4.4–6.7 times compared with the actual operating conditions.

Cleaner Skies during the COVID-19 Lockdown

Abstract During spring 2020, the COVID-19 pandemic caused massive reductions in emissions from industry and ground and airborne transportation. To explore the resulting atmospheric composition changes, we conducted the BLUESKY campaign with two research aircraft and measured trace gases, aerosols, and cloud properties from the boundary layer to the lower stratosphere. From 16 May to 9 June 2020, we performed 20 flights in the early COVID-19 lockdown phase over Europe and the Atlantic Ocean. We found up to 50% reductions in boundary layer nitrogen dioxide concentrations in urban areas from GOME-2B satellite data, along with carbon monoxide reductions in the pollution hot spots. We measured 20%–70% reductions in total reactive nitrogen, carbon monoxide, and fine mode aerosol concentration in profiles over German cities compared to a 10-yr dataset from passenger aircraft. The total aerosol mass was significantly reduced below 5 km altitude, and the organic aerosol fraction also aloft, indicative of decreased organic precursor gas emissions. The reduced aerosol optical thickness caused a perceptible shift in sky color toward the blue part of the spectrum (hence BLUESKY) and increased shortwave radiation at the surface. We find that the 80% decline in air traffic led to substantial reductions in nitrogen oxides at cruise altitudes, in contrail cover, and in resulting radiative forcing. The light extinction and depolarization by cirrus were also reduced in regions with substantially decreased air traffic. General circulation–chemistry model simulations indicate good agreement with the measurements when applying a reduced emission scenario. The comprehensive BLUESKY dataset documents the major impact of anthropogenic emissions on the atmospheric composition.

Pilot randomized controlled trial evaluating the effect of random nicotine delivery on cigarettes per day and smoke exposure

BackgroundMany smokers report attempting to quit each year, yet most relapse, in part due to exposure to smoking-related cues. It is hypothesized that extinction of the cue-drug association could be facilitated through random nicotine delivery (RND), thus making it easier for smokers to quit. The current study aimed to evaluate the effects of RND on smoking cessation-related outcomes including cigarettes per day (CPD) and exhaled carbon monoxide (CO). MethodsParticipants were current smokers (>9 CPD) interested in quitting. Novel trans-mucosal, orally dissolving nicotine films, developed by Bionex Pharmaceuticals, were used in the study. The pharmacokinetic profile of these films was assessed in single (Experiment 1) and multiple-dose (Experiment 2) administrations prior to the smoking cessation study (Experiment 3). In Experiment 3, participants were randomized 1:1:1 to recieve 4 nicotine films per day of either: placebo delivery (0 mg), steady-state delivery (2 mg), or random nicotine delivery (RND) (0 mg or 4 mg). After two weeks, participants were advised to quit (target quit date, TQD) and were followed up 4 weeks later to collect CPD and CO and to measure dependence (Penn State Cigarette Dependence Index; PSCDI) and craving (Questionnaire of Smoking Urges; QSU-Brief). Means and frequencies were used to describe the data and repeated measures ANOVA was used to determine differences between groups. ResultsThe pharmacokinetic studies (Experiment 1 and 2) demonstrated that the films designed for this study delivered nicotine as expected, with the 4 mg film delivering a nicotine boost of approximately 12.4 ng/mL across both the single and the multiple dose administration studies. The films reduced craving for a cigarette and were well-tolerated, overall, and caused no changes in blood pressure or heart rate. Using these films in the cessation study (Experiment 3) (n = 45), there was a significant overall reduction in cigarettes smoked per day (CPD) and in exhaled CO, with no significant differences across groups (placebo, steady-state, RND). In addition, there were no group differences in dependence or craving. Adverse events included heartburn, hiccups, nausea, and to a lesser extent, vomiting and anxiety and there were no differences across groups. ConclusionOverall, this pilot study found that RND via orally dissolving films was feasible and well tolerated by participants. However, RND participants did not experience a greater reduction in self-reported CPD and exhaled CO, compared with participants in the steady-state and placebo delivery groups. Future studies to evaluate optimal RND parameters with larger sample sizes are needed to fully understand the effect of RND on smoking cessation-related outcomes.

Comprehensive Analysis of Engine Power, Combustion Parameters, and Emissions of a B30 Biodiesel-Powered IC Engine

Using the AVL BOOST 2016 Simulations, the effects of biodiesel B30 (30% biodiesel + 70% diesel volume) on diesel engine performance, combustion, and emissions were studied. Simulated cases for diesel fuels and B30 biodiesel were compared to experimental results at full load at 1250, 1500, and 1750 rpm. Biodiesel B30 reduces power and effective torque, according the findings of various fuel parameters. Biodiesel B30 includes more oxygen, which aids in proper oxidation in the combustion chamber and reduces carbon monoxide levels. Once compared to diesel, biodiesel raised brake-specific fuel usage by 5%. When comparing Pure Diesel to B30, NOx emissions increased marginally, reaching 2.57 percent.

Influence of nanoparticles on emission and performance characteristics of biodiesel-diesel blends in a DI diesel engine

ABSTRACT In this experimental work, the effects of copper oxide (CuO) nanoparticles on emissions and performance of 4.4 kW diesel engine powered by palm biodiesel were studied. Palm biodiesel of 20% by volume was blended with diesel fuel (B20). Each test fuel blend was doped with CuO nanoparticles with concentrations of 25, 50, and 75 ppm. Experimentations were carried out for 0%, 25%, 50%, 75%, and 100% engine loads at a constant speed of 1500 rpm. Different parameters, such as brake thermal efficiency (BTE), brake-specific energy consumption (BSEC), carbon monoxide (CO), carbon dioxide (CO2), hydrocarbons (HC), nitrogen oxides (NOx), and smoke opacity were analysed. From the results, it is observed that by using CuO nanoparticles along with B20, BTE (1.18%-7.69%) were significantly increased and BSFC (4.12%-6.76) were lowered. Besides, by using CuO nanoparticles, there were also substantial reductions in CO (2.21%-8.86%). Furthermore, there is an insignificant increase in HC (0.3%-9.78%), CO2 (2.38%-5.97%), and NOx (1.75%-5.27%) emissions when compared to B20 blend. However, when compared to diesel fuel all the emissions were low for all biodiesel blends except NOx emission. Overall, it is concluded that CuO could be considered as a appropriate petroleum additive for palm biodiesel blends.

Cu As Co-Catalyst for the Photo-Electrochemical CO Reduction on Multi-Junction Photoabsorbers

Substantial research effort has been dedicated to the electrochemical reduction of CO2 (CO2R) to higher carbon products throughout the recent years, baring the promise of a production pathway for green fuels and chemicals.1 However, only little progress has been achieved in the light driven heterogeneous CO2R catalysis, especially considering selective processes towards C2+ products. This arises from the additional complexity of photo-electrochemical reactions, which means that not only the sluggish reaction kinetics, high overpotentials and low selectivity of CO2R, but also the insufficient voltage and sensitivity towards harsh electrolyte conditions of photoabsorbers have to be encountered. Considering CO2R as multi-step process with CO as intermediate mitigates some issues of the process, e.g. the necessary overpotential is reduced and a higher selectivity towards valuable products can be achieved.2 Multi-junction solar stacks can provide operating voltages >2 V, which is sufficient for reducing CO2 to CO with high efficiencies or even produce multi-carbon products from CO while oxidizing water as anode reaction.3 In this work, we designed a process for photo-electrochemical CO reduction with multi-junction photoabsorbers. We start out by showing photo-electrochemical modelling of tandem photoabsorbers that emphasizes the advantages of CO as reactant compared to CO2. Further, we focus on the preparation of a nano-structured Cu catalyst, the most common material for reducing CO to C2+. Therefore, the electrochemical deposition and surface characterization using SEM, EDX and XPS of the catalyst on a dark model electrode coated with a sputter deposited TiO2 protection layer will be presented. Moreover, the CO reduction performance of the model at different potentials are characterized. In addition, the light transmission of the model electrode is reported, baring the possibility of illuminating the photoelectrode from the catalyst front side in mind. Lastly, the transfer of the model catalyst to a photoabsorber as well as the design of a photo-electrochemical flow-cell are discussed. Nitopi, S. et al. Progress and Perspectives of Electrochemical CO2 Reduction on Copper in Aqueous Electrolyte. Rev. 119, 7610–7672 (2019)1.Wang, L. et al. Electrochemical Carbon Monoxide Reduction on Polycrystalline Copper: Effects of Potential, Pressure, and pH on Selectivity toward Multicarbon and Oxygenated Products. ACS Catal. 8, 7445–7454 (2018)Seger, B., Hansen, O. & Vesborg, P. C. K. A Flexible Web-Based Approach to Modeling Tandem Photocatalytic Devices. RRL 1, e201600013 (2017). Figure 1

Fuel Efficiency Improvement &amp; Knocking Reduction System Using 2-Stroke Petrol Engine By Coolant Injection

Abstract— In internal combustion engines, the water injection, also known as an anti-detonant injection, is spraying water into the cylinder or incoming air-fuel mixture to cool the combustion chamber of the engine, allowing for greater compression ratios and eliminating the problem of engine knocking. This effectively reduces the air intake temperature in the combustion chamber. The reduction of the air intake temperature allows for higher ignition timing to be employed, which ultimately increases the power output of the engine. Depending on the engine, improvement in power and fuel efficiency can also be obtained by injecting water. Water injection may also reduce carbon monoxide emissions. The purpose of this experiment is to investigate the effect of water injection on the engine performance, exhaust gas temperature, and exhaust emission of the S.I. engine, water is injected in specific quantities with compressed air. Single cylinder, two-stroke, air-cooled, 100 cc petrol engines were used in this experiment. Obtained data will compare to calculate the performance of specific fuel consumption, which will get without a water supply to a petrol engine based on performance. The performance test is conducted to find out the fuel efficiency and is compared with conventional engine present also emission is to be carried out to find CO (carbon monoxide) emissions. Keywords— anti-detonate injection, engine knocking, fuel efficiency, water injection, two-stroke

Combustion and Emission Characteristics of a Diesel Engine Fueled with Crude Palm Oil Blends at Various Idling Speeds

At present, the preparation cost of biodiesel is still higher than that of diesel. Thus, directly using vegetable oil before transesterification can greatly reduce the cost. This study investigated the application characteristics of the direct use of crude palm oil (CPO) in a common rail direct injection (CRDI) diesel engine. In this study, the combustion characteristics, engine performance, and emission characteristics of the CRDI diesel engine operated with CPO0 (neat diesel fuel), CPO10 (10% CPO blended with 90% diesel fuel by volume), CPO30 (30% CPO blended with 70% diesel fuel by volume), and CPO50 (50% CPO blended with 50% diesel fuel by volume) at three idling speeds (750 rpm, 1500 rpm, and 2250 rpm) were evaluated. The results obtained from the experiment elucidate that combustion starts earlier by increasing the idling speed. The addition of CPO to diesel fuel resulted in a decrease in the peak in-cylinder pressure at all idle speeds and a decrease in the maximum heat release rate (HRRmax) at 750 and 1500 rpm, but an increase in HRRmax at 2250 rpm. On the other hand, increasing idle speed is beneficial for reducing carbon monoxide (CO), hydrocarbons (HC), and nitrogen oxides (NOx), but it increases smoke emissions. In addition, adding 10% and 30% CPO to diesel fuel can reduce both HC, NOx, and smoke emissions simultaneously.

Mechanism of CO selective catalytic reduction denitration on Fe–Mn/AC catalysts at medium and low temperatures under oxygen atmosphere

To explore the modification mechanism of Fe and Mn on activated carbon and the denitration mechanism by selective catalytic reduction of carbon monoxide (CO-SCR) on Fe–and Mn-loaded activated carbon (Fe–Mn/AC) catalysts at medium and low temperatures under 8% oxygen, we selected a coconut shell activated carbon as a catalyst carrier and prepared Fe–Mn/AC catalysts. The physical adsorption of CO mainly occurs at low temperatures, and an increase in temperature is beneficial to the CO denitration activity of the metal active components. High Fe2+ content increases the main active sites of the CO + NO reaction, and high Mn3+ content inhibits the conversion of γ-Fe2O3 to α-Fe2O3 and increases the denitration activity. Surface oxygen species (Oα) with high reactivity and mobility are also formed during the denitration process. After denitration, Oα is mainly converted to the lattice oxygen (Oβ), and Mn2+ and Mn3+ are oxidized to Mn4+ in a small amount. The iron oxides and manganese oxides penetrate the internal structure of the catalyst and destroys its oxide crystal structure and the surface functional groups of the activated carbon, resulting in the formation of more oxygen vacancies and lattice defects. Consequently, reduction characteristics and absorption capacities increased and the spectrum peaks of H2-TPR, CO-TPR, and NO-TPR shifted to low temperatures. Moreover, the number of Lewis and Brønsted acid sites increased, resulting in sites that are more reactive. The denitration process involves the following four steps: (1) adsorption of reactant molecules, (2) dissociation of adsorbed molecules, (3) catalytic denitration by metal active components and recombination of active substances for denitration, and (4) product molecule desorption and diffusion.

Production of C3 -C6 Acetate Esters via CO Electroreduction in a Membrane Electrode Assembly Cell.

Electrocatalytic carbon monoxide reduction has been previously reported to yield a range of carbonaceous products including alcohols, hydrocarbons and carboxylic acids. However, esters, an important family of organic compounds, have not been formed. Herein, we report the electrosynthesis of C3 to C6 acetate esters (H3 C-(C=O)-O-R) from carbon monoxide using copper catalysts in a membrane electrode assembly cell. Ethyl acetate and propyl acetate could be produced with an unprecedented total Faradaic efficiency (FE) of ∼22 % and with a current density of up to -55 mA cm-2 , alongside minor quantities of methyl acetate and butyl acetate. The esters are produced via the addition reaction of ethenone (H2 C=C=O) and alcohols produced during CO reduction. We show that the near water-free reaction conditions and the high local pH play key roles in the formation of the esters.

Production of C3–C6 Acetate Esters via CO Electroreduction in a Membrane Electrode Assembly Cell

AbstractElectrocatalytic carbon monoxide reduction has been previously reported to yield a range of carbonaceous products including alcohols, hydrocarbons and carboxylic acids. However, esters, an important family of organic compounds, have not been formed. Herein, we report the electrosynthesis of C3 to C6 acetate esters (H3C−(C=O)−O−R) from carbon monoxide using copper catalysts in a membrane electrode assembly cell. Ethyl acetate and propyl acetate could be produced with an unprecedented total Faradaic efficiency (FE) of ∼22 % and with a current density of up to −55 mA cm−2, alongside minor quantities of methyl acetate and butyl acetate. The esters are produced via the addition reaction of ethenone (H2C=C=O) and alcohols produced during CO reduction. We show that the near water‐free reaction conditions and the high local pH play key roles in the formation of the esters.