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Showing papers on "Methanol published in 2021"


Journal ArticleDOI
22 Mar 2021
TL;DR: In this article, the authors reported that CO2 can dissociate at sulfur vacancies in MoS2 nanosheets to yield surface-bound CO and O at room temperature, thus enabling a highly efficient low-temperature hydrogenation of CO2 to methanol.
Abstract: The low-temperature hydrogenation of CO2 to methanol is of great significance for the recycling of this greenhouse gas to valuable products, however, it remains a great challenge due to the trade-off between catalytic activity and selectivity. Here, we report that CO2 can dissociate at sulfur vacancies in MoS2 nanosheets to yield surface-bound CO and O at room temperature, thus enabling a highly efficient low-temperature hydrogenation of CO2 to methanol. Multiple in situ spectroscopic and microscopic characterizations combined with theoretical calculations demonstrated that in-plane sulfur vacancies drive the selective hydrogenation of CO2 to methanol by inhibiting deep hydrogenolysis to methane, whereas edge vacancies facilitate excessive hydrogenation to methane. At 180 °C, the catalyst achieved a 94.3% methanol selectivity at a CO2 conversion of 12.5% over the in-plane sulfur vacancy-rich MoS2 nanosheets, which notably surpasses those of previously reported catalysts. This catalyst exhibited high stability for over 3,000 hours without any deactivation, rendering it a promising candidate for industrial application. The catalytic hydrogenation of CO2 to methanol is a crucial reaction for the recycling of this greenhouse gas, although the selection and related performance of commercial catalysts is still limited. Now, the authors introduce sulfur vacancy-rich MoS2 nanosheets as a superior catalyst for this process, rivalling the commercial benchmark system.

201 citations


Journal ArticleDOI
TL;DR: Carbon dioxide (CO2) hydrogenation to methanol with H2 produced with renewable energy represents a promising path for the effective utilization of a major anthropogenic greenhouse gas, in which cat...
Abstract: Carbon dioxide (CO2) hydrogenation to methanol with H2 produced with renewable energy represents a promising path for the effective utilization of a major anthropogenic greenhouse gas, in which cat...

135 citations


Journal ArticleDOI
15 Feb 2021-Energy
TL;DR: A comprehensive review of hydrogen production from methanol is presented in this paper, which is conducive to the prospective development of a hydrogen-methanol economy, including catalysts, catalysts with spinel structures, and catalysts that have high selectivity towards H2 and CO2.

127 citations


Journal ArticleDOI
TL;DR: Ni(OH)2 nanosheet arrays are in situ prepared on Ni foam through very straightforward ultrasonication in HCl solution and the following rinsing and drying procedures as mentioned in this paper.
Abstract: Ni(OH)2 nanosheet arrays are in situ prepared on Ni foam through very straightforward ultrasonication in HCl solution and the following rinsing and drying procedures. Value-added formate and hydrogen could be co-produced by selective oxidation of methanol without carbon dioxide emissions and water reduction over Ni(OH)2 nanosheet arrays bifunctional electrocatalysts. Energy depletion for hydrogen evolution from water could be reduced by integrating with selective methanol oxidation rather than oxygen evolution. The prepared Ni(OH)2 nanosheet arrays exhibits high activity for selective methanol oxidation in alkaline methanol-water solution. It gives a low potential of only 1.36 V (vs. reversible hydrogen electrode) to drive the current density of 100 mA cm−2. The faradaic efficiencies of formate are approximately 100% with the current densities from 10 mA cm−2 to 100 mA cm−2. Moreover, it is easy to separate the anodic and cathodic products without help of any membrane, which greatly simplifies the electrolysis system.

115 citations


Journal ArticleDOI
TL;DR: In this paper, Ni is atomically dispersed over α-MoC via carbon bridge bonds, forming a Ni1-Cx motif on the carbide surface, which can effectively stabilize the isolated Ni1 sites over the substrate, rendering maximized active site density and high structural stability.
Abstract: Methanol-water reforming is a promising solution for H2 production/transportation in stationary and mobile hydrogen applications. Developing inexpensive catalysts with sufficiently high activity, selectivity, and stability remains challenging. In this paper, nickel-supported over face-centered cubic (fcc) phase α-MoC has been discovered to exhibit extraordinary hydrogen production activity in the aqueous-phase methanol reforming reaction. Under optimized condition, the hydrogen production rate of 2% Ni/α-MoC is about 6 times higher than that of conventional noble metal 2% Pt/Al2O3 catalyst. We demonstrate that Ni is atomically dispersed over α-MoC via carbon bridge bonds, forming a Ni1-Cx motif on the carbide surface. Such Ni1-Cx motifs can effectively stabilize the isolated Ni1 sites over the α-MoC substrate, rendering maximized active site density and high structural stability. In addition, the synergy between Ni1-Cx motif and α-MoC produces an active interfacial structure for water dissociation, methanol activation, and successive reforming processes with compatible activity.

112 citations


Journal ArticleDOI
TL;DR: In this article, the authors reported that water enabled mild oxidation of methane into methanol with >99% selectivity over Au single atoms on black phosphorus (Au1/BP) nanosheets under light irradiation.
Abstract: As a 100% atom-economy process, direct oxidation of methane into methanol remains as a grand challenge due to the dilemma between activation of methane and over-oxidation of methanol. Here, we report that water enabled mild oxidation of methane into methanol with >99% selectivity over Au single atoms on black phosphorus (Au1/BP) nanosheets under light irradiation. The mass activity of Au1/BP nanosheets reached 113.5 μmol gcatal−1 in water pressured with 33 bar of mixed gas (CH4:O2 = 10:1) at 90 °C under light irradiation (1.2 W), while the activation energy was 43.4 kJ mol−1. Mechanistic studies revealed that water assisted the activation of O2 to generate reactive hydroxyl groups and •OH radicals under light irradiation. Hydroxyl groups reacted with methane at Au single atoms to form water and CH3* species, followed by oxidation of CH3* via •OH radicals into methanol. Considering the recycling of water during the whole process, we can also regard water as a catalyst. It is important but challenging to oxidize methane by O2 into methanol under ambient conditions. Here, the authors achieved mild oxidation of methane into methanol over Au single atoms on black phosphorus nanosheets with the help of water under light irradiation.

98 citations


Journal ArticleDOI
01 Apr 2021-Small
TL;DR: In this paper, a single atom-confinement and a strategy are reported toward single ruthenium atoms dispersion over porous carbon nitride surface, which is well confirmed by EXAFS absorption spectrometric analysis unveiling the cationic coordination environment for the single-atomic-site R-N/C intercalation in the first coordination shell.
Abstract: With increasing concerns for global warming, the solar-driven photocatalytic reduction of CO2 into chemical fuels like methanol is a propitious route to enrich energy supplies, with concomitant reduction of the abundant CO2 stockpiles. Herein, a novel single atom-confinement and a strategy are reported toward single ruthenium atoms dispersion over porous carbon nitride surface. Ruthenium single atom character is well confirmed by EXAFS absorption spectrometric analysis unveiling the cationic coordination environment for the single-atomic-site ruthenium center, that is formed by Ru-N/C intercalation in the first coordination shell, attaining synergism in N-Ru-N connection and interfacial carrier transfer. From time resolved fluorescence decay spectra, the average carrier lifetime of the RuSA-mC3 N4 system is found to be higher compared to m-C3 N4 ; the fact uncovering the crucial role of single Ru atoms in promoting photocatalytic reaction system. A high yield of methanol (1500 µmol g-1 cat. after 6 h of the reaction) using water as an electron donor and the reusability of the developed catalyst without any significant change in the efficiency represent the superior aspects for its potential application in real industrial technologies.

95 citations


Journal ArticleDOI
TL;DR: In this article, both ignition delay times and laminar flame speeds of pure methanol, n-heptane and their blends at various blending ratios were measured at engine-relevant conditions.

93 citations


Journal ArticleDOI
04 Feb 2021
TL;DR: In this paper, a selective photocatalytic oxidation of methane at room temperature using quantum-sized bismuth vanadate nanoparticles as the catalyst and oxygen as a mild oxidant was reported.
Abstract: The direct oxidation of methane to more desirable, one-carbon oxygenated molecules such as methanol and formaldehyde offers a pathway towards a more sustainable chemical industry as the current commercial reforming process involving two steps features a high carbon footprint and energy consumption. Here, we report the selective photocatalytic oxidation of methane at room temperature using quantum-sized bismuth vanadate nanoparticles as the catalyst and oxygen as a mild oxidant. The reaction offers a high selectivity, of 96.6% for methanol or 86.7% for formaldehyde, under optimum wavelength and intensity of light, reaction time and amount of water solvent. Comprehensive characterizations disclose a multistep reaction mechanism in which the activation of methane by the hydroxyl radical determines the reaction rate. This work broadens the avenue towards the selective conversion of the greenhouse gas methane into desirable chemical products in a sustainable way. The conversion of methane to target one-carbon oxygenates relies on a two-step process that is carbon and energy intensive. Direct oxidation offers a sustainable alternative pathway. Here, the authors report on the selective photocatalytic oxidation of methane at room temperature using bismuth vanadate catalyst, realizing high methanol and formaldehyde selectivity.

90 citations


Journal ArticleDOI
TL;DR: In this article, the authors demonstrate that CO2 is reduced to methanol with 100% selectivity using water as the only electron donor on a carbon nitride-like polymer (FAT) decorated with carbon dots.
Abstract: Artificial photosynthesis of alcohols from CO2 is still unsatisfactory owing to the rapid charge relaxation compared to the sluggish photoreactions and the oxidation of alcohol products. Here, we demonstrate that CO2 is reduced to methanol with 100 % selectivity using water as the only electron donor on a carbon nitride-like polymer (FAT) decorated with carbon dots. The quantum efficiency of 5.9 % (λ=420 nm) is 300 % higher than the previously reported carbon nitride junction. Using transient absorption spectroscopy, we observed that holes in FAT could be extracted by the carbon dots with nearly 75 % efficiency before they become unreactive by trapping. Extraction of holes resulted in a greater density of photoelectrons, indicative of reduced recombination of shorter-lived reactive electrons. This work offers a strategy to promote photocatalysis by increasing the amount of reactive photogenerated charges via structure engineering and extraction before energy losses by deep trapping.

88 citations


Journal ArticleDOI
TL;DR: In this paper, a small amount of Pt Methanol selectivity can be increased from 722% (In2O3) to 911% (058 ¼wt% Pt/In 2O3), at 220°C.

Journal ArticleDOI
15 Feb 2021-Fuel
TL;DR: In this article, a magnetic nano-sized solid catalyst derived from bio-waste Citrus sinensis peel ash (CSPA)@Fe3O4 was developed for the synthesis of biodiesel from waste cooking oil (WCO).

Journal ArticleDOI
TL;DR: Iridium (Ir) catalysts have been extensively applied in homogeneous and photocatalytic CO2 conversion as discussed by the authors, however, CO2 hydrogenation to methanol over the supported Ir catalyst in a heterogeneous flow was not considered.
Abstract: Iridium (Ir) catalysts have been extensively applied in homogeneous and photocatalytic CO2 conversion. However, CO2 hydrogenation to methanol over the supported Ir catalyst in a heterogeneous flowi...

Journal ArticleDOI
01 Oct 2021
TL;DR: In this article, the authors showed that a silica-supported Cu/Mo2CTx (MXene) catalyst achieves a higher intrinsic methanol formation rate per mass Cu than the reference Cu/SiO2 catalyst with a similar Cu loading.
Abstract: Development of efficient catalysts for the direct hydrogenation of CO2 to methanol is essential for the valorization of this abundant feedstock. Here we show that a silica-supported Cu/Mo2CTx (MXene) catalyst achieves a higher intrinsic methanol formation rate per mass Cu than the reference Cu/SiO2 catalyst with a similar Cu loading. The Cu/Mo2CTx interface can be engineered due to the higher affinity of Cu for the partially reduced MXene surface (in preference to the SiO2 surface) and the mobility of Cu under H2 at 500 °C. With increasing reduction time, the Cu/Mo2CTx interface becomes more Lewis acidic due to the higher amount of Cu+ sites dispersed onto the reduced Mo2CTx and this correlates with an increased rate of CO2 hydrogenation to methanol. The critical role of the interface between Cu and Mo2CTx is further highlighted by density functional theory calculations that identify formate and methoxy species as stable reaction intermediates. The valorization of CO2 via its hydrogenation to methanol is a highly sought-after reaction although only a handful of catalysts can efficiently promote this transformation. Here, the authors engineer the interface of a copper catalyst supported on a silica–molybdenum MXene composite, achieving a remarkable performance in the reduction of CO2 to methanol.

Journal ArticleDOI
TL;DR: In this paper, a high-dispersal Rh/In2O3 catalyst with high dispersion was used for selective hydrogenation of CO2 to methanol, achieving a CO2 conversion rate of 17.1 % with methanoline selectivity of 56.1% and a methanolic space time yield of up to 0.5448 gMeOH h−1 gcat−1.

Journal ArticleDOI
TL;DR: In this article, a single atomically dispersed platinum on ruthenium oxide (Pt1/RuO2) was synthesized using a simple impregnation-adsorption method.
Abstract: Single-atom catalysts have been widely investigated for several electrocatalytic reactions except electrochemical alcohol oxidation. Herein, we synthesize atomically dispersed platinum on ruthenium oxide (Pt1/RuO2) using a simple impregnation-adsorption method. We find that Pt1/RuO2 has good electrocatalytic activity towards methanol oxidation in an alkaline media with a mass activity that is 15.3-times higher than that of commercial Pt/C (6766 vs. 441 mA mg‒1Pt). In contrast, single atom Pt on carbon black is inert. Further, the mass activity of Pt1/RuO2 is superior to that of most Pt-based catalysts previously developed. Moreover, Pt1/RuO2 has a high tolerance towards CO poisoning, resulting in excellent catalytic stability. Ab initio simulations and experiments reveal that the presence of Pt‒O3f (3-fold coordinatively bonded O)‒Rucus (coordinatively unsaturated Ru) bonds with the undercoordinated bridging O in Pt1/RuO2 favors the electrochemical dehydrogenation of methanol with lower energy barriers and onset potential than those encountered for Pt‒C and Pt‒Ru. It is still challenging to engineer single-atom catalysts for electrocatalytic methanol oxidation. Here, the authors design Pt single atom supported on RuO2 for highly active methanol oxidation in contrast to the inert Pt single atom supported on carbon.

Journal ArticleDOI
TL;DR: In this paper, the magnetic Fe3O4/ZIF-8 composites were first prepared by incorporating ZIF8 MOF into Fe 3O4 nanoparticles through in-situ approach, and then a vanadium-substituted heteropolyacid (HPA), H6PV3MoW8O40, was encapsulated in the support to afford the solid catalyst.

Journal ArticleDOI
01 Mar 2021-Fuel
TL;DR: In this article, a novel heterogeneous catalyst of phosphomolybdic acid (H3PMo12O40, HPMo)/support graphene oxide (GO) was used for biodiesel.

Journal ArticleDOI
TL;DR: In2O3 is a promising catalyst for methanol synthesis from CO2 hydrogenation as mentioned in this paper, and has attracted considerable interest due to its high meethanol selectivity.
Abstract: As a promising catalyst for methanol synthesis from CO2 hydrogenation, In2O3 has attracted considerable interest due to its high methanol selectivity. Understanding the structure–activity relations...


Journal ArticleDOI
TL;DR: In this paper, a small amount of Cu (molar fraction) was added to the catalysts in order to improve the methanol selectivity and long-term stability.

Journal ArticleDOI
TL;DR: The potential of new trimetallic (Ce, Cu, La) loaded montmorillonite clay catalyst for synthesizing biodiesel using novel non-edible Celastrus paniculatus Willd seed oil via two-step transesterification reaction has been reported along with catalyst characterization.

Journal ArticleDOI
TL;DR: In this paper, a heterogeneous CaO/Ag nano catalyst was developed and applied for biodiesel production from transesterification of soybean oil, which significantly reduced mass transfer resistance of triglycerides during transesterion and improved the mass transfer constants.

Journal ArticleDOI
TL;DR: In this article, a co-axial dielectric barrier discharge (DBD) was used for the partial oxidation of methane (POM) to higher-value liquid fuels and chemicals over supported transition metal catalysts (Ni/γ-Al2O3, Cu/γ−Al 2O3 and Fe/γ −Al 2 O3) at room temperature and atmospheric pressure.
Abstract: Direct conversion of methane into chemicals and fuels under mild conditions has been considered as a ‘holy grail’ of chemistry and catalysis in the 21st century. Plasma-catalytic partial oxidation of methane (POM) to higher-value liquid fuels and chemicals over supported transition metal catalysts (Ni/γ-Al2O3, Cu/γ-Al2O3 and Fe/γ-Al2O3) has been investigated in a co-axial dielectric barrier discharge (DBD) reactor at room temperature and atmospheric pressure. The selectivity of oxygenates was 58.3% in the plasma POM reaction without a catalyst, while the combination of DBD with the catalysts enhanced the selectivity of oxygenates up to 71.5%. Of the three catalysts, Fe/γ-Al2O3 showed the highest methanol selectivity of 36.0% and a significant methanol yield of 4.7%, while the use of Cu/γ-Al2O3 improved the selectivity of C2 oxygenates to 9.4%, which can be attributed to the presence of more acid sites on the surfaces of the Cu catalyst. The possible reaction pathways in the plasma-catalytic POM reaction have been explored by combined means of plasma electrical and optical diagnostics, analysis of gas and liquid products, as well as comprehensive catalyst characterization. The plausible reaction routes for the production of major oxygenate (methanol) on the Fe/γ-Al2O3 surfaces have been proposed. The surface CHx species are found to be critical for methanol synthesis; they can be formed through the direct adsorption of CHx radicals generated in the plasma gas-phase reactions or through the dissociation of adsorbed CH4 on the catalyst surface.

Journal ArticleDOI
TL;DR: In this article, a multi-dimensional ternary composite electrocatalysts of Pt/Ni(OH)2/nitrogen-doped graphene catalysts have been synthesized with 0D Pt nanoparticles on the 2D Ni(OH)/2/NG nanosheets supported by 3D porous nitrogen doped graphene hydrogel, and with a low amount of Pt.

Journal ArticleDOI
01 Jan 2021-Fuel
TL;DR: A low-cost liquid lipase from genetically modified Aspergillus oryzae (Eversa® Transform 2.0) was used in this study for biodiesel production as discussed by the authors.

Journal ArticleDOI
TL;DR: Operando experiments and density functional theory calculations demonstrate that the catalyst is beneficial for CO 2 activation via decreasing the energy barrier of *COOH dissociation to form *CO, leading to high selectivity toward methanol.
Abstract: Using renewable electricity to drive CO2 electroreduction is an attractive way to achieve carbon-neutral energy cycle and produce value-added chemicals and fuels. As an important platform molecule and clean fuel, methanol requires 6-electron transfer in the process of CO2 reduction. Currently, CO2 electroreduction to methanol suffers from poor efficiency and low selectivity. Herein, we report the first work to design atomically dispersed Sn site anchored on defective CuO catalysts for CO2 electroreduction to methanol. It exhibits high methanol Faradaic efficiency (FE) of 88.6 % with a current density of 67.0 mA cm-2 and remarkable stability in a H-cell, which is the highest FE(methanol) with such high current density compared with the results reported to date. The atomic Sn site, adjacent oxygen vacancy and CuO support cooperate very well, leading to higher double-layer capacitance, larger CO2 adsorption capacity and lower interfacial charge transfer resistance. Operando experiments and density functional theory calculations demonstrate that the catalyst is beneficial for CO2 activation via decreasing the energy barrier of *COOH dissociation to form *CO. The obtained key intermediate *CO is then bound to the Cu species for further reduction, leading to high selectivity toward methanol.

Journal ArticleDOI
01 Jun 2021
TL;DR: In this article, the synthesis of dual-functional heterogeneous catalyst for valorizing the plant-based oils to produce biodiesel as a cleaner fuel to conserve the environment and meet the current energy demand is reported.
Abstract: This study reports the synthesis of dual-functional heterogeneous catalyst for valorizing the plant-based oils to produce biodiesel as a cleaner fuel to conserve the environment and meet the current energy demand Pristine carbon as a support for the catalyst is produced from waste date seeds powder before oil extraction and modified with alkaline earth metal oxides to utilize it for transesterification to produce biodiesel The synthesized catalyst before usage is characterized by several techniques which include XRD, SEM, EDS, BET and TPD The catalyst characterization revealed its suitability for transesterification reaction and the process is optimized while the synthesized catalyst is used for the reaction The optimized yield of biodiesel is 9427 wt% when the set parameters of a temperature of 65 °C, time 90 min, methanol to oil molar ratio of 15 and catalyst loading of 4 wt% To commercialize the catalyst, the efficiency was evaluated using oils from different sources to produce biodiesel The kinetic study revealed that while using the synthesized heterogeneous catalyst for transesterification of non-edible oil to produce biodiesel it was not an energy-intensive process Further on, the fuel properties were measured and compared to American ASTM and European EN standards which ensured that the produced biodiesel is of potential and that it can be commercialized Thus, the study gave an overall complete scenario from an economical catalyst to efficient fuel production which can be advantageous in the society

Journal ArticleDOI
TL;DR: In this article, the authors investigated the catalytic activity and deactivation mechanism of a carbon-based solid-acid catalyst in the esterification of oleic acid and methanol.

Journal ArticleDOI
TL;DR: In this article, the complex interplay between nanostructure and product selectivity of nickel-promoted In2O3 in CO2 hydrogenation to methanol was unraveled through in-depth characterization, theoretical simulations, and kinetic analyses.
Abstract: Metal promotion in heterogeneous catalysis requires nanoscale-precision architectures to attain maximized and durable benefits. Herein, we unravel the complex interplay between nanostructure and product selectivity of nickel-promoted In2O3 in CO2 hydrogenation to methanol through in-depth characterization, theoretical simulations, and kinetic analyses. Up to 10 wt.% nickel, InNi3 patches are formed on the oxide surface, which cannot activate CO2 but boost methanol production supplying neutral hydrogen species. Since protons and hydrides generated on In2O3 drive methanol synthesis rather than the reverse water-gas shift but radicals foster both reactions, nickel-lean catalysts featuring nanometric alloy layers provide a favorable balance between charged and neutral hydrogen species. For nickel contents >10 wt.%, extended InNi3 structures favor CO production and metallic nickel additionally present produces some methane. This study marks a step ahead towards green methanol synthesis and uncovers chemistry aspects of nickel that shall spark inspiration for other catalytic applications. Palladium-promoted indium oxide is a catalyst with potential to realize the large-scale conversion of CO2 into the commodity methanol. This work focuses on the low-cost nickel as an alternative appealing promoter, revealing the atomic-level catalyst design unlocking maximal selectivity and activity.