Methanol Gas Research Articles

Switchable catalysis for methanol and synthetic natural gas synthesis from CO2: A techno-economic investigation

The oil and gas sector produces a considerable volume of greenhouse gas emissions, mainly generated from flaring and venting natural gas. Herein, a techno-economic analysis has been performed of a switchable catalytic process to convert the CH4 and CO2 in flared/vented natural gas into syngas or methanol. Specifically, it was shown that depending on greenhouse gas composition, dry methane reforming (DRM), reverse water-gas shift (RWGS), and CO2 methanation could be chosen to valorise emissions in an overall profitable and flexible operation scenario. The switchable process produced methanol and synthetic natural gas as its products, resulting in an annual income of €687m and annual operating expenses of €452m. The pre-tax profit was calculated at €234m, and at the end of the project, the net present value was calculated as €1.9b with a profitability index of 4.7€/€. The expected payback time of this process was ca. 4 years, and with a 35% internal rate of return (IRR). Most importantly, this process consumed 42.8m tonnes of CO2 annually. The sensitivity analysis revealed that variations in operation time, green hydrogen price, and products' prices significantly impacted the profitability of the process. Overall, this techno-economic analysis demonstrated that switchable catalysis in greenhouse gas utilisation processes is profitable, and thus it could play an important role in achieving net zero emissions.

The Use of Arak Bali as a Fuel Influence on Fire Characteristics of Combustion

Analyze the characteristics of gas fuel from arak Bali, like shape and flame speed. Test characteristics such as methanol and ethanol content material gas from arak Bali, after it tested the gas fuel combustion characteristics of arak Bali such as the shape and speed of flame. Testing characteristics such as the content of methane and ethanol gas from arak Bali performed in the forensic laboratory while testing the ignition characteristics of the shape and speed of fuel from evaporating arak Bali done using a helle-shaw cell combustion chamber model. Air mixture ratio variations with gas fuel from arak Bali is 24/1, 25/1, 26/1, 27/1, 28/1, 29/1, 30/1 and 31/1. The observed effect is the shape and speed of the premixed flame propagation in the helle-shaw cell combustion chamber model. The results of the study, the moisture content of the basic ingredients of gas fuel arak Bali consisting of 40% methanol and 60% ethanol. Gas fuel from arak Bali has a stoichiometry air-fuel ratio of 30/1. Getting closer to the stoichiometry air-fuel ratio, flame color changes from reddish color faded to red, reddish blue, blue and bright blue last. The maximum speed of propagation of fire occurring in stoichiometry air-fuel ratio is 328.33 cm/sec.

Gd3+ and Sm3+ doped CeO2 for IT-SOFC and room temperature formaldehyde gas sensing applications

An alternative solid electrolyte is imperative to replace YSZ for better IT-SOFC. Gd3+/Sm3+ doped ceria (Ce0.9Gd0.1O2-δ-GDC1, Ce0.8Gd0.2O2-δ-GDC2, Ce0.8Sm0.2O2-δ-SDC) were synthesized via sol–gel method. These compounds were investigated by using X-ray diffraction (XRD), Field emission scanning electron microscope (FESEM), Energy dispersive X-ray (EDX) spectra, X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR), Raman and impedance spectroscopy. FESEM micrographs manifested that GDC1 has larger grain sizes than GDC2 and SDC. Interestingly, SDC exhibited more grain boundaries than GDC1 and GDC2. These high dense sol–gel derived compounds have exhibited better ionic conductivity than some of the previously reported Gd3+/Sm3+ doped ceria. Furthermore, the selectivity of calcinated GDC1, GDC2 and SDC sensors at room temperature (RT) for ammonia, methanol, ethanol and formaldehyde gases at 100 ppm was examined and found that GDC1 has displayed an applausive selectivity with superior response for formaldehyde gas sensing at RT as an operating temperature. The Raman analysis avowed the presence of oxygen vacancies which were identified as instrumental in both applications. The multiple gases detected by GDC1 at RT might provide various strategies to design novel gas sensors.

Modelling deuterated isotopologues of methanol towards the pre-stellar core L1544

Context. In the extremely cold and dark environments of pre-stellar cores, methanol is formed on the surface of interstellar dust grains and released into the gas phase via non-thermal desorption mechanisms. Gaseous methanol constitutes the starting point for the formation of many massive complex organic molecules and is therefore of utmost importance for the build-up of chemical complexity. Aims. We aim to improve upon a previous model for the prediction of column densities and deuterium fractions of non-deuterated and singly deuterated methanol. Thereby, we try to identify crucial chemical and physical parameters for which the study of deuteration could provide valuable additional constraints. Methods. We employed a gas-grain chemical code to devise a model that is in agreement with the observed column density and deuterium fraction profiles of the innermost region of the pre-stellar core L1544. For that purpose, we developed a new treatment of reactive desorption, deriving an individual reactive desorption efficiency for every product species in a chemical reaction that depends on the reaction enthalpy and type of the underlying surface. Furthermore, we explored several options to promote the diffusion of hydrogen and deuterium atoms over the surface of interstellar dust grains in order to increase methanol formation. Results. Our fiducial model employs diffusion via the quantum tunnelling of hydrogen and deuterium atoms, resulting in CH3OH and CH2DOH column densities that are approximately an order of magnitude lower than the observed values, which is an improvement over the results of the previous model by a factor of 10. The N(CH2DOH)/N(CH3OH) ratio is reproduced within a factor of 1.2 for the centre and 1.8 for the position of the methanol peak. Given the large uncertainties that chemical models typically have, we consider our predictions to be in agreement with the observations. In general, we conclude that a diffusion process with a high diffusion rate needs to be employed to obtain methanol column densities that are in accordance with the observed values. Also, we find that the introduction of abstraction reactions into the methanol formation scheme suppresses deuteration when used in combination with a high diffusion rate.

Cu nanoparticle anchored highly conducting, reusable multifunctional rGO/PANI nanocomposite: A novel material for methanol sensor and a catalyst for click reaction

A novel composite consisting of reduced graphene oxide (rGO) incorporated with polyaniline (PANI) and copper (Cu) nanoparticle has been synthesized through a straightforward interfacial polymerization method. This novel composite exhibits a dual functionality, demonstrating exceptional proficiency as both a methanol sensor and a highly efficient catalyst for click reactions. The remarkable success of this composite can be attributed to the pivotal role of PANI, which acts as a conductive matrix, fostering strong adhesion between copper nanoparticles and rGO sheets. This synergy significantly enhances the surface conductivity of the composite, making it an ideal candidate for various applications. The rGO/PANI/Cu nanocomposite was thoroughly characterized using scanning electron microscopy (SEM), powder X-ray diffraction (XRD) analysis, transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, and Fourier transform infrared (FT-IR) spectroscopy. Notably, our methanol sensor displayed an impressive maximum sensitivity of 64.22% at a methanol concentration of 500 ppm. Furthermore, this sensor exhibited rapid response and recovery times of 30 s and 45 s, respectively, highlighting its effectiveness as a methanol gas sensor at room temperature. Upon exposure to methanol vapors under ambient conditions using a custom laboratory-made setup, the sensor consistently maintained its outstanding sensitivity at 500 ppm methanol. Additionally, the rGO/PANI/Cu composite demonstrated exceptional performance as a heterogeneous catalyst in the synthesis of 1,4-disubstituted-1H-1,2,3-triazoles through a click chemistry approach, underlining its versatility and potential for a wide array of applications.

Exergy and energy analysis of a hybrid natural Gas/Hydrogen liquefaction cycle combined with methanol production plant

This paper presents an innovative renewable multi-generation system designed to simultaneously produce various fuels, including biomass-based methanol, liquid hydrogen, and liquid natural gas. This system is part of a broader strategy aimed at streamlining different processes within a comprehensive plant, enabling the simultaneous production of multiple biomass-based fuels at a single location. The implementation of this system in regions where natural gas liquefaction plants coexist with abundant forest resources allows for the efficient production of all required fuels. In this process, a new configuration leverages to regenerate the waste heat of methanol synthesis process in the diffusion absorption refrigeration cycle integrated to the natural gas liquefaction process to maximize energy and exergy efficiencies. Additionally, three hydrogen liquefaction processes are evaluated to identify the most suitable option based on performance, efficiency, and power consumption. The investigations reveal that the combined mixed refrigerant cycle (CMRC) emerges as the ideal choice for hydrogen liquefaction process, characterized by lower power consumption and a higher coefficient of performance. The energy and exergy efficiencies of biomass gasification and methanol synthesis processes are 87.54% and 80.41%. The energetic coefficient of performance of the natural gas liquefaction process and CMRC is 0.9 and 0.2209. The specific power consumption of natural gas liquefaction process is 0.225 kWh/kgLNG, and the specific power consumption of CMRC is 5.462 kWh/kgLH2. The natural gas liquefaction process is responsible for the highest portion of the total exergy destruction, with 32%.

Composite nanoarchitectonics with reduced-graphene oxide and polyaniline for a highly responsive and selective sensing of methanol vapors

In an approach to develop room temperature, highly responsive and selective methanol gas sensor, reduced graphene oxide-polyaniline nanocomposites have been successfully synthesized through simple chemistry based chemical oxidative synthesis process in the presence of camphor sulfonic acid. Field emission scanning electron microscopy, Raman spectroscopy, and X-ray diffraction, respectively, were used to examine the morphological, vibrational, and structural characteristics of synthesized samples systematically. The morphology of prepared samples was observed as nanoparticles and structure as semi-crystalline in nature. Raman spectra of synthesized samples exhibit all essential bands that confirm the growth of expected samples. Thereafter, these samples were studied as sensors for the detection of 50, 100, 150 and 200 ppm levels of methanol vapors. It was found that 8 wt% reduced graphene oxide doped polyaniline composite exhibits the highest response (%) i.e., 52% at 200 ppm. Furthermore, these sample showed good stability even after 180 days of fabrications. To understand the response of these composites, a sensing mechanism is also discussed. Our results shows that reduced graphene oxide doped polyaniline-based gas sensors showed high response, selectively towards Methanol vapors. Moreover, prepared sensors showed appreciable stability, reproducibility and repeatability making them suitable candidates for commercial production of methanol vapor sensors.

Numerical study on effects of EGR on combustion and NOx emissions of gasoline blended dissociated methanol gas engine

Exhaust gas recirculation (EGR), which can reduce NOx emissions effectively, has been widely studied in engines, but there are few studies using EGR on gasoline blended dissociated methanol gas (GDM) engines. To reduce the NOx emissions of GDM engines, investigation is conducted based on numerical simulation in this study. The accuracy of the engine numerical model is first validated through experimental data, and then the effects of EGR on GDM engine performance are studied, including combustion characteristics and NOx emissions. Numerical simulation results show that the application of EGR reduces the cylinder pressure and the heat release rate of GDM engine, and delays the corresponding crank angle of their peak value respectively. The application of EGR also delays the combustion center, and extends the ignition delay and combustion duration. As EGR rate increases, the NOx emissions decrease significantly. This study offers valuable insights into the potential application of EGR technology in GDM engines.

Linking ice and gas in the Coronet cluster in Corona Australis

Context. During the journey from the cloud to the disc, the chemical composition of the protostellar envelope material can be either preserved or processed to varying degrees depending on the surrounding physical environment. Aims. This works aims to constrain the interplay of solid (ice) and gaseous methanol (CH3OH) in the outer regions of protostellar envelopes located in the Coronet cluster in Corona Australis (CrA), and assess the importance of irradiation by the Herbig Ae/Be star R CrA. CH3OH is a prime test case as it predominantly forms as a consequence of the solid-gas interplay (hydrogenation of condensed CO molecules onto the grain surfaces) and it plays an important role in future complex molecular processing. Methods. We present 1.3 mm Submillimeter Array (SMA) and Atacama Pathfinder Experiment (APEX) observations towards the envelopes of four low-mass protostars in the Coronet cluster. Eighteen molecular transitions of seven species were identified. We calculated CH3OH gas-to-ice ratios in this strongly irradiated cluster and compared them with ratios determined towards protostars located in less irradiated regions such as Serpens SVS 4 in Serpens Main and the Barnard 35A cloud in the λ Orionis region. Results. The CH3OH gas-to-ice ratios in the Coronet cluster vary by one order of magnitude (from 1.2 × 10−4 to 3.1 × 10−3) which is similar to less irradiated regions as found in previous studies. We find that the CH3OH gas-to-ice ratios estimated in these three regions are remarkably similar despite the different UV radiation field intensities and formation histories. Conclusions. This result suggests that the overall CH3OH chemistry in the outer regions of low-mass envelopes is relatively independent of variations in the physical conditions and hence that it is set during the prestellar stage.

Mixed potential type methanol gas sensor based on Gd2Zr2O7 solid state electrolyte and ZnSb2O6 sensing electrode

With the development of methanol fuel cell vehicles, the hidden danger of methanol leakage has become a safety problem that cannot be ignored. The timely and effective detection of methanol is the premise to ensure safety. Herein, a mixed potential type methanol sensor was developed using Gd2Zr2O7 solid state electrolyte and ZnSb2O6 sensing electrode. The fabricated sensor can realize effective detection in a wide range of 0.2–1000 ppm with the sensitivities of − 4.7 mV/ppm and − 55.9 mV/decade to 0.2–5 ppm and 5–1000 ppm methanol. The sensing behavior of the sensor is explained based on mixed potential sensing mechanism in two cases of charge transfer-limiting and mass transport limiting processes. By comparing the sensing behavior under illumination conditions, it is found that the sensing performance of the mixed potential sensor can be improved by adjusting the wavelength and intensity of excitation light. The sensor possessed good repeatability, selectivity and stability in the systematic and detailed evaluation of sensing performances, which proves its potential and reliability for practical application in methanol fuel vehicles.

Assessment of cruise ship decarbonization potential with alternative fuels based on MILP model and cabin space limitation

Alternative fuels are expected to play an increasingly crucial role in the decarbonization of the shipping industry. Previous studies have explored the possibility of ship integrated energy systems that use alternative fuels for emission reduction in a cost-efficient manner. However, the various navigation loads and strict space limitations of ships are usually overlooked when designing the ships' energy systems. To fill this gap, a two-stage optimization model is proposed for designing ship integrated energy systems that incorporate alternative fuels, which incorporates internal combustion engines, fuel cells, energy storage technologies, and other relevant equipment. The model captures the ship's volume and weight limitations for alternative fuel applications, and a large cruise ship sailing in Oceania and the Caribbean is selected as a case study. The application feasibilities of four mainstream alternative fuels, i.e., hydrogen, ammonia, methanol, and natural gas, have been compared with the conventional diesel power system considering the impact of future trends of fuel cost and emission-related policies. The results indicate that more than 60% of greenhouse gas emissions can be reduced by replacing conventional fossil fuels with alternative fuels. Meanwhile, alternative fuel applications are economically competitive when compared to conventional diesel power systems, considering the growing technology readiness level of fuel production and fuel cells. Overall, this study is expected to provide guidance for the utilization of alternative fuels for ships and to identify the optimal ship integrated energy systems solutions.

Rational design of AIEE sensor: Ultrafast detection of methanol in liquid and gaseous states with highly sensitive and selective performance

The convenient and sensitive detection of methanol out of ethanol is still a great challenge due to their similar physical properties. We have designed a tetraphenylethene (TPE)-based AIEE fluorescence probe (TPEP4) with large steric hindrance composed of four large branches to overcome this challenge. Due to its four large branches, TPEP4 displayed substantially brighter fluorescence emission in aromatic solvents and a higher fluorescence quantum yield (12.67% in o-dichlorobenzene) compared to other TPE derivatives in dilute solution. Remarkably, TPEP4 exhibited a methanol-responsive fluorescence quenching in both liquid and film states. Therefore, methanol could be significantly distinguished from ethanol by the fluorescent change of TPEP4. Use of TPEP4 in biodiesel (B100) has multiple advantages, such as rapid response time (0.5 s), high selectivity to methanol, and ultralow limits of detection (LOD). In this case, the TPEP4 film remained its selectivity towards gaseous methanol with an ultralow LOD of 5.63 ppb. To the best of our knowledge, this is the first TPE-based AIEE fluorescence probe for methanol detection that shows significant potential for use in environmental monitoring. Thus, the present work provides a strategy for developing fluorescent sensing materials for volatile organic compound based on AIEE molecules.

Numerical Study on a Diesel/Dissociated Methanol Gas Compression Ignition Engine with Exhaust Gas Recirculation

Hydrogen is the most promising alternative fuel in the field of engines. Exhaust heat-assisted methanol dissociation is an attractive approach for generating hydrogen. In this work, simulations are conducted on a compression ignition engine fueled with different proportions of diesel-dissociated methanol gas (DMG) blends at intermediate engine speed, full load, and 0% EGR ratio. The results reveal that the indicated thermal efficiency and indicated mean effective pressure are greatly enhanced, combustion efficiency is increased, and regular emissions of CO, HC, and soot are reduced, while NOx emissions are reduced with increased DMG substitution. In addition, a simulation is conducted at an intermediate engine speed, full load, 15% DMG substitution ratio, and varying EGR ratios of 0–20%. The results indicate that the dual-fuel engine outperforms the original engine with respect to power, fuel economy, and regular emissions, once an optimal EGR rate is adopted.

Metal-Organic Framework Based Triboelectric Nanogenerator for a Self-Powered Methanol Sensor with High Sensitivity and Selectivity.

Triboelectric nanogenerators have shown great potential in the area of self-powered gas sensors in the past decade. In this paper, we developed a triboelectric nanogenerator (TENG) based on spiky structured ZIF-8@ZnO, which can harvest energy with high efficiency and act as a self-powered methanol sensor. The open-circuit voltage and short-circuit current generated by a ZIF-8@ZnO-based TENG is 58 V and 10 μA, achieving 2.4 times and 3.3 times enhancement compared to ZnO-based TENGs. The TENG can charge capacitors fast and light up at least 40 LEDs. ZIF-8@ZnO-based TENGs show good sensitivity and selectivity to methanol gas at room temperature due to the porous structure provided by ZIF-8 and the heterostructure of ZIF-8@ZnO. The response of ZIF-8@ZnO-based TENG to methanol reaches 30.35% at 100 ppm with excellent response (∼5.9 s) and recovery time (∼2.2 s). This work demonstrates the application of MOF-modified metal oxide semiconductors based on a self-powered gas sensor and proposes a promising solution to enhance the output performance and sensing properties of TENGs based on metal oxide semiconductors.

Stabilized bismuth nanoplasmonics for selective CO2 reduction to methanol at a heterointerface

Photocatalytic CO2 transformation into value-added chemicals has enormous industrial importance, but is challenging to operate with multifaceted performances in activity, selectivity, stability and regenerability. We successfully achieved this goal by integrating plasmonic bismuth nanoparticles and non-plasmonic redox heterojunctions. This maximizes the product selectivity by directing the reaction paths via the electric field of localized surface plasmon resonances (LSPRs). We attach non-noble plasmonic Bi particles with a shell of BiOCl to self-assembled TiO2 nanosheets, creating a transformative hybrid plasmonic nanostructure for CO2-to-methanol conversion. It exhibits high photoactivity (235.26 µmol g-1 h-1), outstanding selectivity (∼90 % sole carbon/methanol product, ∼10 % H2) and is free of backward reactions, thanks to the synergistic effects of the hybrid nanostructure: complementary light absorption, strong local fields, and an adaptive redox heterojunction. Macro-to-micro experiments and simulations reveal that the BiOCl shell is responsible for stabilizing Bi to generate robust LSPRs, to induce 7–9 times local field enhancement, enabling efficient and selective CO2-to-methanol conversion at the TiO2-BiOCl heterointerfaces. This work demonstrates a durable and easily-regenerable photocatalyst with the capability to tune the CO2 reduction pathway by plasmon fields. Moreover, it provides a unique paradigm to harvest hydrogen carriers (liquid methanol and hydrogen gas) from the greenhouse gas CO2.

YSZ-based mixed potential sensor attached with NiSb2O6 electrode for methanol monitoring

Methanol, as the raw material of new fuel cells, is flammable, explosive and dangerous. The leakage monitoring of methanol in high-temperature methanol fuel cells is necessary and challenging. Herein, a wide detection range of Yttria Stabilized Zirconia (YSZ)-based mixed potential methanol gas sensor equipped with NiSb2O6 sensing electrode (SE) was developed. The sensor possesses wide detection range of 0.1–500 ppm and presents sensitivity of − 84.13 mV/decade to 5–500 ppm methanol at 570 °C. The sensor also has good moisture resistance, reliable repeatability, long-term stability and obvious selectivity for methanol. We also show the adsorption characteristics as well as the possible chemical reaction of methanol with NiSb2O6 material during transmission process. This work offers a new gas-sensing detection strategy for methanol leakage in high-temperature fuel cells and leads to more consideration on the selection of SE materials.

Self-Assembling Nanoarchitectonics of Twisted Nanofibers of Fluorescent Amphiphiles as Chemo-Resistive Sensor for Methanol Detection.

The inhalation, ingestion, and body absorption of noxious gases lead to severe tissue damage, ophthalmological issues, and neurodegenerative disorders; death may even occur when recognized too late. In particular, methanol gas present in traces can cause blindness, non-reversible organ failure, and even death. Even though ample materials are available for the detection of methanol in other alcoholic analogs at ppm level, their scope is very limited because of the use of either toxic or expensive raw materials or tedious fabrication procedures. In this paper, we report on a simple synthesis of fluorescent amphiphiles achieved using a starting material derived from renewable resources, this material being methyl ricinoleate in good yields. The newly synthesized bio-based amphiphiles were prone to form a gel in a broad range of solvents. The morphology of the gel and the molecular-level interaction involved in the self-assembly process were thoroughly investigated. Rheological studies were carried out to probe the stability, thermal processability, and thixotropic behavior. In order to evaluate the potential application of the self-assembled gel in the field of sensors, we performed sensor measurements. Interestingly, the twisted fibers derived from the molecular assembly could be able to display a stable and selective response towards methanol. We believe that the bottom-up assembled system holds great promise in the environmental, healthcare, medicine, and biological fields.

Simulation of CH3OH ice UV photolysis under laboratory conditions

Context. Methanol is the most complex molecule that is securely identified in interstellar ices. It is a key chemical species for understanding chemical complexity in astrophysical environments. Important aspects of the methanol ice photochemistry are still unclear, such as the branching ratios and photodissociation cross sections at different temperatures and irradiation fluxes. Aims. This work aims at a quantitative agreement between laboratory experiments and astrochemical modelling of the CH3OH ice UV photolysis. Ultimately, this work allows us to better understand which processes govern the methanol ice photochemistry present in laboratory experiments. Methods. We used the code ProDiMo to simulate the radiation fields, pressures, and pumping efficiencies characteristic of laboratory measurements. The simulations started with simple chemistry consisting only of methanol ice and helium to mimic the residual gas in the experimental chamber. A surface chemical network enlarged by photodissociation reactions was used to study the chemical reactions within the ice. Additionally, different surface chemistry parameters such as surface competition, tunnelling, thermal diffusion, and reactive desorption were adopted to check those that reproduce the experimental results. Results. The chemical models with the code ProDiMo that include surface chemistry parameters can reproduce the methanol ice destruction via UV photodissociation at temperatures of 20, 30, 50, and 70 K as observed in the experiments. We also note that the results are sensitive to different branching ratios after photolysis and to the mechanisms of reactive desorption. In the simulations of a molecular cloud at 20 K, we observed an increase in the methanol gas abundance of one order of magnitude, with a similar decrease in the solid-phase abundance. Conclusions. Comprehensive astrochemical models provide new insights into laboratory experiments as the quantitative understanding of the processes that govern the reactions within the ice. Ultimately, these insights can help us to better interpret astronomical observations.

Wearable electrochemical gas sensor for methanol leakage detection

To ensure worker and environmental safety in daily work, it is an urgent need in industrial safety field to construct wearable sensing devices for volatile organic compounds (VOCs) leakage detection in chemical production. In this work, methanol gas was selected as the research object, and the wearable gas sensor has been constructed on a flexible substrate for systematically investigating the sensing process and performance, as well as practicality of leak detection. Electrochemical measurements demonstrated the constructed sensor possessed obvious electrocatalytic capability at 0.6 V, good linearity in the detection range of 20–100 ppm, 200–3000 ppm and 4000–30,000 ppm, and low limit of detection (3.3 ppm). This methanol gas sensor also exhibited high reproducibility, lifetime, and stable sensitivity according to the continuous repeated and long-time stability measurement results. High gas-sensitive selectivity to methanol under multiple interference gases, such as acetone, toluene, xylene, methylene chloride, acetonitrile had been demonstrated, and the response change under selectivity test was less than 16%. Significantly, it also displayed detectability in actual methanol gasoline sample, and the response time was less than 16 s. Moreover, experimental results also have proved higher content of platinum (20%) with better theoretical CO-tolerance capacity and sensing sensitivity. When maintaining a platinum content of 20%, the introduction of support materials with high specific surface area and conductivity in place of activated carbon will ensure that all sites are catalytically active, further improve the sensing sensitivity and be extended to the design of other VOCs sensors.

Quartz Crystal Microbalance Coated with Polyacrylonitrile/Nickel Nanofibers for High-Performance Methanol Gas Detection.

This study describes a sensor based on quartz crystal microbalance (QCM) coated by polyacrylonitrile (PAN) nanofibers containing nickel nanoparticles for methanol gas detection. The PAN/nickel nanofibers composites were made via electrospinning and electrospray methods. The QCM sensors coated with the PAN/nickel nanofiber composite were evaluated for their sensitivities, selectivities, and stabilities. The morphologies and elemental compositions of the sensors were examined using a scanning electron microscope-energy dispersive X-ray. A Fourier Transform Infrared spectrometer was used to investigate the elemental bonds within the nanofiber composites. The QCM sensors coated with PAN/nickel nanofibers offered a high specific surface area to enhance the QCM sensing performance. They exhibited excellent sensing characteristics, including a high sensitivity of 389.8 ± 3.8 Hz/SCCM, response and recovery times of 288 and 251 s, respectively, high selectivity for methanol compared to other gases, a limit of detection (LOD) of about 1.347 SCCM, and good long-term stability. The mechanism of methanol gas adsorption by the PAN/nickel nanofibers can be attributed to intermolecular interactions, such as the Lewis acid-base reaction by PAN nanofibers and hydrogen bonding by nickel nanoparticles. The results suggest that QCM-coated PAN/nickel nanofiber composites show great potential for the design of highly sensitive and selective methanol gas sensors.