Alcohol Fuels Research Articles

Recent Progress on the Materials of Oxygen Ion-Conducting Solid Oxide Fuel Cells and Experimental Analysis of Biogas-Assisted Electrolysis over a LSC Anode

In this work, the recent achievements in the application of solid oxides fuel cells (SOFCs) are discussed. This paper summarizes the progress in two major topics: the materials for the electrolytes, anode, and cathode, and the fuels used, such as hydrocarbon, alcohol, and solid carbon fuels. Various aspects related to the development of new materials for the main components of the materials for electrocatalysts and for solid electrolytes (e.g., pure metals, metal alloys, high entropy oxides, cermets, perovskite oxides, Ruddlesden–Popper phase materials, scandia-stabilized-zirconia, perovskite oxides, and ceria-based solid electrolytes) are reported in a coherent and explanatory way. The selection of appropriate material for electrocatalysts and for solid electrolyte is crucial to achieve successful commercialization of the SOFC technology, since enhanced efficiency and increased life span is desirable. Based on the recent advancements, tests were conducted in a biogas-fueled Ni-YSZ/YSZ/GDC/LSC commercial cell, to elucidate the suitability of the LSC as an anode. Results obtained encourage the application of LSC as an anode in actual SOFC and SOFEC systems. Thus, H2-SOFC demonstrated a satisfying ASR value, while, for biogas-assisted electrolysis, the current values slightly increased compared to the methane-SOFEC, and for a 50/50 biogas mixture of methane and carbon dioxide, the corresponding value presented the higher increase.

Numerical Analysis of the Effect of Ethanol-Gasoline Blends on a Single-Cylinder Spark-Ignition Engine Performance and Emissions

— With the rapid increase in the number of vehicles fueled by gasoline plying on the roads, there has been a rising need in the search for alternative fuels, which are more environmental friendly in order to reduce the amount of vehicular exhaust emissions. This can be achieved by using blended mixtures of gasoline with alcoholic fuels among which, ethanol is found to be most suitable due to its easy availability, low costs, safety and low impact on the engine performance. This study aims to investigate the performance of a single-cylinder, four-stroke spark-ignition engine using different ethanol-gasoline blends, namely E0, E10, E20 and E30. The engine's torque, brake power, brake thermal efficiency, brake-specific fuel consumption, and exhaust emissions were analysed using numerical simulation. Results revealed that raising the proportion of ethanol in the fuel mixture resulted in reduced brake power and torque upto 16% as a result of decrease in calorific value of the mixture. The engine's brake thermal efficiency decreased by upto 3% while the brake-specific fuel consumption increased upto 12% with increase in ethanol concentration. Exhaust emissions, including NOx and HC, were found to be influenced by engine speed, with NOx emissions increasing and HC emissions decreasing as speed increased. The study also revealed that increasing ethanol concentration in the fuel resulted in reduced engine exhaust emissions by upto 47% and 10% for NOX and HC emissions respectively. The study concluded that among all the blends used, optimum performance was obtained for E30 blend with reduction in exhaust emissions but at the expense of slight reduction in engine performance.

Alcohol fuels in SI engines: a comprehensive state-of-the-art review on combustion, performance, and environmental impacts

Alcohol fuels in SI engines: a comprehensive state-of-the-art review on combustion, performance, and environmental impacts

Experimental study on the effects of n-butanol and n-propanol on the spray and combustion characteristics of diesel/biodiesel blends in a constant volume combustion chamber

The depletion of fossil fuel resources and the escalating environmental impact of greenhouse gas emissions have intensified the global exploration of renewable and sustainable energy sources. Biodiesel produced from vegetable oils and animal fats has become a promising alternative to conventional diesel fuel due to its renewability and lower carbon emission. This study investigates the differences in spray, combustion and flame characteristics between soybean-based biodiesel blended with propanol and butanol at various ratios. The results indicate that the liquid spray penetration length of biodiesel mixed with propanol and butanol exceeds that of soybean-based biodiesel. And the increase of spray penetration is accompanied by a longer flame lift-off length, which indicates the improvement of spray characteristics. Regarding combustion, alcohol-fuel blends exhibit a reduction in peak combustion pressure but an increase in peak apparent heat release rate. Additionally, these fuels show a shorter ignition delay and combustion duration. The peak natural flame luminosity is lower for alcohol fuels, suggesting their potential to reduce carbon soot production and support low-carbon combustion. These experimental results contribute to advancing research on cleaner, more efficient and renewable fuels, thereby reducing reliance on conventional fossil fuels.

Reaction Rate Rules of Intramolecular H-Migration Reaction Class for RIORIIOO·Radicals in Ether Combustion.

The intramolecular H-migration reaction of RIORIIOO· radicals constitute a key class of reactions in the low-temperature combustion mechanism of ethers. Despite this, there is a dearth of direct computations regarding the potential energy surface and rate constants specific to ethers, especially when considering large molecular systems and intricate branched-chain structures. Furthermore, combustion kinetic models for large molecular ethers generally utilize rate constants derived from those of structurally similar alcohols or alkane fuels. Consequently, chemical kinetic studies involve the calculation of energy barriers and rate rules for the intramolecular H-migration reaction class of RIORIIOO· radicals, which are systematically conducted using the isodesmic reaction method (IRM). The geometries of the species participating in these reactions are optimized, and frequency calculations are executed using the M06-X method in tandem with the 6-31+G(d,p) basis set by the Gaussian 16 program. Moreover, the M06-2X/6-31+G(d,p) method acts as the low-level ab initio method, while the CBS-QB3 method is utilized as the high-level ab initio method for calculating single-point energies. Rate constants at the high-pressure-limit are computed based on the reaction class transition state theory (RC-TST) by ChemRate program, incorporating asymmetric Eckart tunneling corrections for intramolecular H-migration reactions across a temperature range of 500 to 2000 K. It was found that the isodesmic reaction method gives accurate energy barriers and rate constants, and the rate constants of the H-migration reaction for RIORIIOO· radicals diverge from those of comparable reactions in alkanes and alcohol fuels. There are significant disparities in energy barriers and rate constants across the entire reaction classes of the H-migration reaction for RIORIIOO· radicals, necessitating the subdivision of the H-migration reaction into subclasses. Rate rules are established by averaging the rate constants of representative reactions for each subclass, which is pivotal for the advancement of accurate low-temperature combustion reaction mechanisms for ethers.

Precisely Regulating Asymmetric Charge Distribution by Single‐Atom Central Doped Ag‐Based Series Clusters for Enhanced Photoreduction of CO2 to Alcohol Fuels

AbstractHigh efficiently photocatalytic CO2 reduction (CO2RR) into liquid fuels in pure water system remains challenged. Iron polyphthalocyanine (FePPc) with strong light harvesting, unique Fe‐N4 structure, abundant pores, and good stability could serve as a promising catalyst for CO2 photoreduction. To further improve the catalytic efficiency, herein, symmetry‐breaking Fe sites are constructed by coupling with atomically precise M1Ag24 (M=Ag, Au, Pt) series clusters. Especially, the introduction of Pt1Ag24 causes the most asymmetric charge distribution of Fe in FePPc (followed by Au1Ag24 and Ag25), leading to the favorable CO2 adsorption and activation. In addition, Pt1Ag24‐FePPc exhibits the most effective photogenerated carriers transfer and separation. As a result, Pt1Ag24‐FePPc shows the methanol/ethanol yield of 48.55/32.97 μmol ⋅ gcat−1 ⋅ h−1 in H2O‐CO2 system under visible light irradiation, ~1.65/1.25‐fold, 1.83/1.37‐fold, and 3.60/1.61‐fold higher than that of Au1Ag24‐FePPc, Ag25‐FePPc, and FePPc, respectively. This work provides a concept for precisely construction and regulation symmetry‐breaking sites of cluster‐based catalysts for effective CO2 conversion.

Alcohols as Biofuel for a Diesel Engine with Blend Mode—A Review

In the era of decarbonization driven by environmental concerns and stimulated by legislative measures such as Fit for 55, the industry and transportation sectors are increasingly replacing petroleum-based fuels with those derived from renewable sources. For many years, the share of these fuels in blends used to power compression ignition engines has been growing. The primary advantage of this fuel technology is the reduction of GHG emissions while maintaining comparable engine performance. However, these fuel blends also have drawbacks, including limited ability to form stable mixtures or the requirement for chemical stabilizers. The stability of these mixtures varies depending on the type of alcohol used, which limits the applicability of such fuels. This study focuses on evaluating the impact of eight types of alcohol fuels, including short-chain (methanol, ethanol, propanol) and long-chain alcohols (butanol, pentanol, hexanol, heptanol, and octanol), on the most critical operational parameters of an industrial engine and exhaust emissions. The engines being compared operated at a constant speed and under a constant load, either maximum or close to maximum. The study also evaluated the effect of alcohol content in the mixture on combustion process parameters such as peak cylinder pressure and heat release, which are the basis for parameterizing the engine’s combustion process. Determining ignition delay and combustion duration is fundamental for optimizing the engine’s thermal cycle. As the research results show, both the type of alcohol and its concentration in the mixture influence these parameters. Another parameter important from a usability perspective is engine stability, which was also considered. Engine performance evaluation also includes assessing emissions, particularly the impact of alcohol content on NOx and soot emissions. Based on the analysis, it can be concluded that adding alcohol fuel to diesel in a CI engine increases ignition delay (up to 57%), pmax (by approximately 15–20%), HRRmax (by approximately 80%), and PPRmax (by approximately 70%). Most studies indicate a reduction in combustion duration with increasing alcohol content (by up to 50%). For simple alcohols, an increase in thermal efficiency (by approximately 15%) was observed, whereas for complex alcohols, a decrease (by approximately 10%) was noted. The addition of alcohol to diesel slightly worsens the stability of the CI engine. Most studies pointed to the positive impact of adding alcohol fuel to diesel on NOx emissions from the compression ignition engine, with the most significant reductions reaching approximately 50%. Increasing the alcohol fuel content in the diesel blend significantly reduced soot emissions from the CI engine (by up to approximately 90%).

The Commercial Determinants of Men's Health Promotion: A Case Study of Gambling, Nonnies, and Athleisurewear.

Although the social determinants of health have guided equity work with the tailoring of men's health promotion programs, the role of, and potential for, the commercial determinants of health in those interventions is rarely addressed and poorly understood. While four commercial products, tobacco, alcohol, ultra-processed food, and fossil fuels, account for more than a third of global deaths, there is a need to recognize that consumer goods industries can make both positive and negative contributions to health. This article begins much-needed discussions about what we might learn from, and strategically tap in the commercial sector to seed, scale, and sustain men's health promotion programs. Three case studies, online sports betting, beer and the rise of the nonny, and athleisurewear, are discussed. Connections between online sports betting and masculinities explain young men's disproportionate involvement and gambling addictions with recommendations to legislate an end to gambling advertisements and de-incentivize industry profiteering through penalties and higher taxes. Regarding beer and the rise of the nonny, brewers have innovated with non-alcoholic beer based on shifting consumption patterns and masculinities in their core market-men. The nonny reminds health promoters to know their end-user's values and behaviors to bolster program acceptability. Detailing Under Armour and Lululemon, two highly gendered but diversifying athleisurewear brands, the complexities of, and potential for, leveraging public health and industry collaborations are underscored. Taken together, the article findings suggest men's health promoters should rigorously explore tapping key commercial entities and tax revenues to advance the health of men and their communities.

Effects of alcohol fuels on SACI engine and analyze of prediction of SACI engine performance by artificial neural networks

The combustion characteristics of spark assistant compression ignition mode under different loads and fuels were explored, as well as by constructing artificial neural networks(ANN) model, the prediction ability of different algorithms for engine performance was discussed. Burning methanol and n-butanol can help to improve IMEP and induce earlier spontaneous combustion. The knock intensity(KI) of engine fueled with methanol was highest followed by n-butanol and gasoline, but maximum amplitude of filtered pressure oscillation(MAPO) shows the opposite trend. KI showed great positive liner correlation with ignition timing. Methanol showed the most outstanding tolerance on the compression ignition state. Fueled with methanol can decreased equivalent brake specific fuel consumption(ESFC) up to 52.9 % compared with the initial SI gasoline engine. N-butanol can improve BSNOx, BSTHC and BSCO concurrently, however fueled with methanol will worsen BSNOx. ANN model for engine combustion, economy and emissions performance was built. The prediction accuracy of Bayesian regularization algorithm for engine performance predicting was highest, but it have no advantage in the calculating times when the amount of data was large while the Levenberg-Marquardt algorithm would be the ideal efficient. The mean square error of ESFC and emissions parameters under scaled conjugate gradients algorithm always poorest.

Performance Analysis and Optimum Design of a Direct Alcohol Fuel Cell Fueled with Mixed Alcohols

Performance Analysis and Optimum Design of a Direct Alcohol Fuel Cell Fueled with Mixed Alcohols

Overlooked Impacts of Alcohols in Electro-H2O2 and Fenton Chemistry.

Alcohols are promising fuels for direct alcohol fuel cells and are common scavengers to identify reactive oxygen species (ROS) in electro-Fenton (EF) systems. However, the side impacts of alcohols on oxygen reduction reactions and ROS generation are controversial due to the complex interactions between electrodes and alcohol-containing electrolytes. Herein, we employed synchrotron-Fourier-transform infrared spectroscopy and electron paramagnetic resonance technologies to directly observe the changes of chemical species and electrochemical properties on the electrode surface. Our studies suggested that alcohols exhibited different limiting degrees on proton (H+) mass transfer toward the catalytic surface, following an order of methanol < ethanol < isopropanol < tert-butyl alcohol (TBA). In addition, the formation of hydrophobic TBA clusters at high concentrations (>400 mM) resulted in a significant reduction in ionic conductivity and an elevation in charge transfer resistance, which impedes H+ mass transfer and raises the energy barrier for 2e- oxygen reduction reaction processes. Moreover, the organic radical •CH2(CH3)2CH2OH produced by the interaction of Fe3+ and •OH with the alcohol in the EF system serves as a crucial intermediate in facilitating H2O2 regeneration, which complicates the quenching effect of alcohols on •OH identification. Therefore, it is recommended that methanol should be used as the scavenger instead of TBA and the concentration should be less than 400 mM in EF systems.

Butanol Used as a Potential Alternative Fuel Blend with N-Decane and Diesel in CI Engines for Marine Application

For compression ignition engines, butanol is the most promising alternative fuel, in comparison with other alcoholic fuels. Butanol is superior to other alcoholic fuels because it has excellent physical and chemical properties that make it appropriate for diesel fuel blends. When butanol and diesel are blended, butanol is fully miscible in all proportions. Because butanol is hygroscopic, it does not absorb moisture from the environment. Because acetone-butanol-ethanol (ABE) fermentation may create butanol, it is commonly touted as a possible biofuel. This research is a significant step in gaining a thorough understanding of the effects of butanol on the fuel based on hydrocarbon. The fuel's molecular interactions mixes are studied using infrared (IR) spectroscopy. Binary mixes of butanol and n-decane, are investigated initially. After that, the mixture of butanol and diesel is investigated. When butanol is mixed with diesel, it forms strong bonds including the components of biodiesel that contain groups of esters. Furthermore, the possibility of employing Infrared spectroscopy for numerical mix analysis is assessed. The spectra are provided to enable a highly precise determination of the butanol concentration.

Health and equity impacts of global consultancy firms

BackgroundConcern is growing over the power, influence, and threats to health and equity from the operations of large global consultancy firms. Collectively, these firms support a neoliberal policy environment promoting business interests ahead of public health. Global consultancy firms act as commercial determinants of health, an evolving area of research over recent years. However, this research mainly focuses on specific corporations or industry sectors, especially those which produce harmful products, including ultra-processed food, alcohol, and fossil fuels. It is therefore important to expand the focus to include large global consultancy firms and place a public health and equity lens over their operations.Main bodyGlobal consultancy firms have wide-ranging conflicts of interest. These arise from the ‘revolving door’ employment strategies between their own staff and those from government and regulatory bodies. These firms also advise governments on taxation and other matters while concurrently advising corporate clients on ways to minimise taxation. They advise fossil fuel corporations while also advising governments on climate and health policies. These firms undermine the capabilities of the public sector through the outsourcing of traditional public sector roles to these private interests. Consultancy firms foster private interests through their engagement with the higher education sector, and thereby weaken the tradition of transparent management of university affairs by accountable university councils. While private consultancies cannot be blamed for all the negative consequences for health and equity caused by the problems associated with globalisation and advanced capitalism, they have played a role in amplifying them.ConclusionAddressing the negative impacts of global consultancy firms will require strengthening the public sector, enforcing greater transparency, accountability, and minimising conflicts of interest. It will also demand critical thought, counter discourses, and activism to reframe the narratives supporting neo-liberal ideas of governance that are promoted in both government and business arenas.

Precisely Regulating Asymmetric Charge Distribution by Single-Atom Central Doped Ag-Based Series Clusters for Enhanced Photoreduction of CO2 to Alcohol Fuels.

High efficiently photocatalytic CO2 reduction (CO2RR) into liquid fuels in pure water system remains challenged. Iron polyphthalocyanine (FePPc) with strong light harvesting, unique Fe-N4 structure, abundant pores, and good stability could serve as a promising catalyst for CO2 photoreduction. To further improve the catalytic efficiency, herein, symmetry-breaking Fe sites are constructed by coupling with atomically precise M1Ag24 (M=Ag, Au, Pt) series clusters. Especially, the introduction of Pt1Ag24 causes the most asymmetric charge distribution of Fe in FePPc (followed by Au1Ag24 and Ag25), leading to the favorable CO2 adsorption and activation. In addition, Pt1Ag24-FePPc exhibits the most effective photogenerated carriers transfer and separation. As a result, Pt1Ag24-FePPc shows the methanol/ethanol yield of 48.55/32.97 μmol·gcat-1·h-1 in H2O-CO2 system under visible light irradiation, ~ 1.65/1.25-fold, 1.83/1.37-fold, and 3.6/1.61-fold higher than that of Au1Ag24-FePPc, Ag25-FePPc, and FePPc, respectively. This work provides a concept for precisely construction and regulation symmetry-breaking sites of cluster-based catalysts for effective CO2 conversion.

Effect of intake valve lift and binary alcohol (bioethanol+isobutanol) addition on energy, exergy, sustainability, greenhouse gas impact and cost analysis in a hydrogen/diesel dual fuel engines

Greenhouse gas emissions are a significant problem contributing to global warming and climate change and it is essential to increase the use of renewable and biomass-derived fuels in internal combustion engines to reduce greenhouse gas formation. Alcohol fuels and hydrogen have become prominent in recent years due to less harmful emission levels as a result of combustion. While there are very few studies in the literature on ternary mixture + hydrogen in terms of energy and exergy, there is a gap on the effect of the valve lift amount. The aim of this study is to investigate the effects of binary alcohol addition and variable intake valve lift (IVL) in hydrogen-diesel dual fuel mode on energy, exergy, sustainability, and greenhouse gas emissions. The experiments are conducted at variable torque conditions, involving three different IVL values (4, 4.46, and 4.9 mm) and four different fuel combinations (diesel, diesel + H2, diesel + binary alcohol, and diesel + binary alcohol + H2). The binary alcohol addition consists of 10% bioethanol and 10% isobutanol volumetrically, while in the dual-fuel mode, hydrogen is injected into the cylinder at a constant flow rate. When the results are examined, the highest energy and exergy values are obtained with the IVL-Diesel + H2 operation, providing on average 11% and 8% higher exergy efficiency compared to IVL 4-Diesel and IVL 4.46-Diesel studies, respectively. Additionally, the exergy destruction in the IVL-Diesel + H2 study shows an average decrease of 16% and 12%, respectively, compared to the IVL 4-Diesel and IVL 4.46-Diesel studies. Additionally, significant reductions in emissions are achieved. In the IVL 4.9-EB20+H2 study, HC, CO, and CO2 emissions decrease by 28%, 40%, and 28%, respectively, compared to the IVL 4.0 study. When examining the GHG emission impact, it is analysed that operating a single-cylinder engine with EB20+H2 fuels under 4.9 mm IVL conditions emits, on average, 36% and 32% less GHG impact over a one-year period compared to IVL 4-Diesel and IVL 4.46-Diesel studies, respectively.

Physical properties and diesel engine combustion of blends of alcohols with military jet fuel JP-5

Military operations may involve the use of jet fuel in a diesel engine, and the blending of alcohols with jet fuel is a way to introduce decarbonization into military operations. This study explored the effect of blending n-alcohols with navy jet fuel JP-5 on physical properties and combustion in a diesel engine. Blends containing 10 %, 20 %, and 30 % of ethanol, propanol, butanol, pentanol, hexanol, octanol, and one mixture of 10 % methanol/80 % octanol had densities (0.80 to 0.81 g/mL) that fell within military specifications for diesel. Most mixtures' flash points (16.5 to 65.0 °C) were below the military spec of 60 °C, which is higher than that of commercial aviation fuel. Most mixture viscosities (4.74 to 9.99 mm2/s) were within the jet fuel specifications at −20 °C but below the diesel fuel specification at 40 °C. Combustion of the alcohol/JP-5 mixtures in a diesel engine showed that increasing alcohol content lengthened the ignition delay (IGD). For some of the alcohols, shortening the carbon chain length on the alcohol led to longer IGDs with later combustion phasing that was most noticeable at lighter engine loads. The longer IGDs associated with the shorter alcohol fuels (and increased alcohol percentage) rapidly led to very high rates of energy release. The relative IGDs (IGD mixture/IGD JP-5) were less than 1.2 for the 10 % alcohol mixtures, between 1.0 and 1.4 for the 20 % alcohol mixtures, and between 1.0 and 1.9 for the 30 % alcohol mixtures excluding the 30 % ethanol mixture that did not combust. From the combustion metrics perspective, the longer carbon chain alcohols were most similar to the base jet fuel. Overall, the larger alcohols had physical properties and combustion metrics that were closer to those of the JP-5 jet fuel.

Power generation characteristics and optimum alcohol concentration in bio-direct alcohol fuel cell using chitin family electrolyte

Direct alcohol fuel cells (DAFCs) have the potential to become the next-generation portable energy device. However, the development of DAFC requires the explore new electrolytes without fuel crossover. In this study, DAFC with bio-electrolyte have been fabricated and their characteristics have been investigated. Ethanol impermeability measurements revealed that the crossover of ethanol in the chitin and chitosan electrolytes is extremely low. This result indicates that the chitin family electrolyte has the potential of DEFC electrolytes. Furthermore, DAFCs using the chitin electrolyte have been investigated for various alcohol fuels (methanol, ethanol, 1-propanol, and 1-butanol fuels), and the optimum fuel concentrations to achieve the maximum power density in these DAFCs have been determined. In addition, these results and viscosity measurements clarify the optimum alcohol fuel concentration can be obtained by adding the water molecules required for the proton generating reaction to the water molecules required to stabilize alcohol in water.

Ultrasonic synthesis of borophene as a 2D electrode material with high electrocatalytic activity for use in fuel cell applications

Green energy systems must be able to provide a significant proportion of the energy needed to meet the ever-increasing demand for energy. Fuel cells are a promising solution to bridge the gap in the green energy transition. This study aims to enhance the energy efficiency of fuel cells by utilizing 2D supported nanocatalysts in the anode compartment. Borophene was synthesized using the liquid phase exfoliation method to be used as a support structure due to its superior properties. To use borophene as a supporting material in methanol fuel cells, a borophene-palladium hybrid structure (Pd@Borophene) was prepared using the chemical reduction method. The scanning electron microscopy (SEM) images showed that the obtained particle had a partially formed layered structure. The electrocatalytic activity of the Pd@Borophene was investigated through anodic reactions in Direct Methanol Alcohol Fuel Cells (DMFC). Electrochemical analyses were conducted to compare the effect of borophene on Pd and Pd@borophene nanocatalysts on the anodic reaction. The anodic peak current value of methanol oxidation for Pd@borophene was found to be 24.3 mA/cm2, which is approximately four times higher than that of unsupported Pd nanoparticles. Additionally, the ratio of forward current (If) to reverse current (Ib), which serves as an indicator of catalyst poisoning, was determined to be 2.27. This study contributes significant findings to the literature by demonstrating that borophene, an advanced 2D material, can be synthesized using a low-cost liquid phase exfoliation method and can be utilized in fuel cell applications for energy generation.

Thermodynamic Reactivity Study during Deflagration of Light Alcohol Fuel-Air Mixtures with Water

In this paper, a thermodynamic and reactivity study of light alcohol fuels was performed, based on experimental and numerical results. We also tested the influence of water addition on fundamental properties of the combustion reactivity dynamics in closed vessels, like the maximum explosion pressure, maximum rate of pressure rise and the explosion delay time of alcohol–air mixtures. The substances that we investigated were as follows: methanol, ethanol, n-propanol and iso-propanol. All experiments were conducted at initial conditions of 323.15 K and 1 bar in a 20 dm3 closed testing vessel. We investigated the reactivity and thermodynamic properties during the combustion of liquid fuel–air mixtures with equivalence ratios between 0.3 and 0.7 as well as some admixtures with water, to observe water mitigation effects. All light alcohol samples were prepared at the same initial conditions on a volumetric basis by mixing the pure components. The volumetric water content of the admixtures varied from 10 to 60 vol%. The aim of water addition was to investigate the influence of thermodynamic properties of light alcohols and to discover to which extent a water addition may accomplish mitigation of combustion dynamics and thermodynamic reactivity.

In-situ and operando Grazing Incidence XAS: a novel set-up and its application to model Pd electrodes for alcohols oxidation

Abstract In this article, we present an in-situ and operando time-resolved X-ray Absorption Spectroscopy (XAS) technique which exploits a combination of Grazing Incidence XAS (GIXAS) and Fixed Energy X-ray Absorption Voltammetry (FEXRAV), the Grazing Incidence FEXRAV (GI-FEXRAV). A case-study is also outlined. Palladium ultra-low loadings were deposited above Au polycrystalline iso-oriented substrates adopting three different deposition methods: surface-controlled electrochemical methods, direct electrodeposition, and physical vapour deposition (PVD). These catalytical surfaces were prepared for the investigation by GI-FEXRAV of the Pd oxidation/dissolution phenomenon that could occur when the metal is used in the anodic compartment of Direct Alcohol Fuel Cells (DAFCs) or in electrochemical reformers. Moreover, we report a robust, low cost and versatile procedure to obtain wide and flat iso-oriented gold substrates that can mimic monocrystalline gold (1 1 1) in the electrochemical response. The use of GI-FEXRAV for the operando characterization of the catalysts, in conjunction with the designed experimental cell and our flexible Au-based electrochemical substrates show an invaluable potential in the operando study of fundamental phenomena in heterogeneous electrocatalysis model systems and, due to its versatility, paves the way to further studies on a wide selection of electrochemical systems.