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1. l-Serine O-sulphate and l-threonine O-sulphate are degraded in the presence of pyridoxal 5'-phosphate to yield equimolar amounts of the corresponding keto acid, ammonia and sulphate. 2. Pyridoxal catalyses the same reactions at a faster rate. 3. One of a number of bi- or ter-valent metal ions must be present for these degradations to proceed. The reaction rates are dependent on a number of factors including pH and the nature of the metal ion used. 4. Studies with related sulphate esters indicate that the alpha-hydrogen atom and the amino group are essential for activity. 5. Spectral changes during the pyridoxal and pyridoxal 5'-phosphate catalysis of l-serine O-sulphate breakdown suggest the formation of a Schiff base. 6. The mechanism for these reactions appears to be in accordance with the general mechanism proposed for pyridoxal-catalysed alphabeta-elimination reactions.

As part of its move towards net zero, the chemical industry, over time, will transition away from fossil-based chemical feedstocks towards more sustainable, 'green' carbon—biomass, recycled waste and captured carbon dioxide. One gateway to transforming these feedstocks into the vital chemicals and fuels society relies on is via synthesis gas or 'syngas'—a gaseous mixture of chemical building blocks (H2, CO and CO2). While today the majority of syngas is produced via steam reforming of natural gas, commercially available technologies are enabling syngas production and transformation from sustainable feedstocks. The optimization of sustainable syngas technologies would not be possible without the integrated development of both catalyst and process technology and the associated skills in chemistry and chemical engineering. This paper covers three example technologies that are unlocking the role of syngas as a gateway to sustainable fuels and chemicals and highlights the innovative developments in catalyst and process design that have enabled their optimization and commercialization. This article is part of the discussion meeting issue 'Green carbon for the chemical industry of the future'. [ABSTRACT FROM AUTHOR]

The carbonyl‐alkyne metathesis reaction is a powerful method for the synthesis of α,β‐unsaturated carbonyls. We now report on the development of a halogen‐bond catalyzed protocol for both the intra‐ and intermolecular reaction. Our studies revealed that methanol is a highly efficient solvent and that a very broad range of functional groups are tolerated under the reaction conditions. Mechanistic studies support the proposed halogen‐bond interaction. Furthermore, the halogen‐bond protocol is compared with other available catalytic systems for these reactions. [ABSTRACT FROM AUTHOR]

With the change of the global climate, the technology of hydrogenation of CO2 to methanol has attracted considerable attention all over the world. In this work, the hydrogenation of carbon dioxide to methanol over Cu/ZnO/ZrO2 catalysts is carried out at atmospheric pressure. The effect of process conditions on the catalytic performance is examined to determine the most effective conditions. The reaction kinetics are then investigated by using two Langmuir–Hinshelwood (L–H) kinetic models. The kinetic parameters are determined and statistical tests and residual analyses indicate that both kinetic models are reliable. However, the fitting effects for CO2 and CO are different between the two models. Moreover, the structural characteristics of the catalytic under different conditions are examined by TEM, XRD, and XPS. It can also be found that oxygen vacancies can facilitate the activation of carbon dioxide and the desorption of methanol during the reaction. The reactants and products undergo reactions in which oxygen migrates and reoxidation occurs with surface oxygen vacancies, resulting in an increase in the concentration of oxygen vacancies. [ABSTRACT FROM AUTHOR]

Increasing the number of active sites can enhance activity for the methanol oxidation reaction (MOR), yet achieving a high density of active sites that can simultaneously regulate the adsorption of *OH and *CO remains highly challenging. Herein, a new class of intermetallic Pd3Pb/NxCy with a high density of active sites that can simultaneously regulate the adsorption of *OH and *CO by the Mott–Schottky (M–S) effect was synthesized, and its alkaline MOR was studied. The MOR activity of optimized Pd3Pb IM/MNC (Pd3Pb intermetallic compound loaded on moderately N-doped C, with M–S effect) is 17.83 A mg−1Pd, which is 6.5 times higher than the 2.76 A mg−1Pd of Pd3Pb IM/C (without M–S effect). The ECSA of Pd3Pb IM/MNC (95.2 m2 per gram of Pd) is higher than that of Pd/C (28 m2 per gram of Pd). In addition, Pd3Pb IM/MNC could achieve a power density of 225.5 mW cm−2 while maintaining stable discharge performance (31.9% attenuation at 0.8 V (vs. RHE) for 10 hours). Experimental and theoretical studies have shown that the adsorption of *CO was appropriately attenuated by pyrrolic-N-Pd sites, and the adsorption of *OH was enhanced by pyridinic-N-Pb sites. [ABSTRACT FROM AUTHOR]

So far, it is still extremely challenging to develop an efficient catalyst for deep oxidation of methanol at low temperature. Herein, we report the construction of the highly dispersed CuAg alloy on the surface of Ce0.90In0.10Oδ nanorods support for catalyzing methanol deep oxidation. The composition, structure and properties of catalysts were characterized by X‐ray diffraction (XRD), transmission electron microscopy (TEM), ultraviolet‐visible (UV‐vis) spectroscopy and X‐ray photoelectron spectroscopy (XPS). The results show that the CuxAg100‐x/Ce0.90In0.10Oδ alloy catalysts exhibit superior catalytic activity and stability compared to pure Ag/Ce0.90In0.10Oδ, with the highest activity observed for Cu40Ag60/Ce0.90In0.10Oδ, accompanied by the light‐off temperature (T50) and full conversion temperature (T90) of 115 and 145 °C, respectively. This is attributed to the synergistic effect of CuAg alloy, which results in electron transfer, generating more Ag0, and enhanced interaction between CuAg alloy and the support, leading to increased Ce3+ content and higher oxygen vacancy concentration. This work successfully applies CuAg alloy catalysts in thermo‐catalytic reaction, offering promising prospects for CuAg alloy catalysts in the methanol deep oxidation. [ABSTRACT FROM AUTHOR]

The atomically dispersed metal catalysts with full atomic utilization and well‐defined site structure hold great promise for various catalytic reactions. However, the single metallic site limits the comprehensive reaction performance in most reactions. Here, we demonstrated a photo‐induced neighbour‐deposition strategy for the precise synthesis of diatomic Ir1Pd1 on In2O3 applied for CO2 hydrogenation to methanol. The proximity synergism between diatomic sites enabled a striking promotion in both CO2 conversion (10.5 %) and methanol selectivity (97 %) with good stability of 100 h run. It resulted in record‐breaking space‐time yield to methanol (187.1 gMeOH gmetal−1 hour−1). The promotional effect mainly originated from stronger CO2 adsorption on Ir site with assistance of H‐spillover from Pd site, thus leading to a lower energy barrier for *HCOO pathway. It was confirmed that this synergistic effect strongly depended on the dual‐site distance in an angstrom scale, which was attributed to weaker *H spillover and less electron transfer from Pd to Ir site as the Pd‐to‐Ir distance increased. The average dual‐site distance was evaluated by our firstly proposed photoelectric model. Thus, this study introduced a pioneering strategy to precisely synthesize homonuclear/heteronuclear diatomic catalysts for facilitating the desired reaction route via diatomic synergistic catalysis. [ABSTRACT FROM AUTHOR]

Catalytic CO2 conversion to renewable fuel is of utmost importance to establish a carbon-neutral society. Bioelectrochemical CO2 reduction, in which a solid cathode interfaces with CO2-reducing bacteria, represents a promising approach for renewable and sustainable fuel production. The rational design of biocatalysts in the biohybrid system is imperative to effectively reduce CO2 into valuable chemicals. Here, we introduce methanol adapted Sporomusa ovata (S. ovata) to enhance the slow metabolic activity of wild-type microorganisms to our semiconductive silicon nanowires (Si NWs) array for efficient CO2 reduction. The adapted whole-cell catalysts enable an enhancement of CO2 fixation with a superior faradaic efficiency on the poised Si NWs cathode. The synergy of the high-surface-area cathode and the adapted strain achieves a CO2-reducing current density of 0.88 ± 0.11 mA/cm2, which is 2.4-fold higher than the wild-type strain. This new generation of biohybrids using adapted S. ovata also decreases the charge transfer resistance at the cathodic interface and facilitates the faster charge transfer from the solid electrode to bacteria.

A manganese pincer complex Mn‐2 for the homogeneously catalysed conversion of CO/H2 to methanol was developed using a novel PNP ligand design. Compared to the previous state‐of‐the‐art catalyst system Mn‐1, the presented Mn‐2 with different substituents at the P‐atoms led to a significant increase of the reaction rate (TOF up to >1600 h−1). [ABSTRACT FROM AUTHOR]

A novel Ni(OH)2/MnCO3 hybrid catalyst was developed for high-performing alkaline methanol electro-oxidation, which could well overcome the shortages of inactive MnCO3 and low intrinsic Ni(OH)2 due to the good synergistic catalysis effect from the Jahn–Teller distortion effect. [ABSTRACT FROM AUTHOR]

Establishment of a scaling relation among the reaction intermediates is highly important but very much challenging on complex surfaces, such as surfaces of high entropy alloys (HEAs). Herein, we designed an interpretable machine learning (ML) approach to establish a scaling relation among CO2 reduction reaction (CO2RR) intermediates adsorbed at the same adsorption site. Local Interpretable Model‐Agnostic Explanations (LIME), Accumulated Local Effects (ALE), and Permutation Feature Importance (PFI) are used for the global and local interpretation of the utilized black box models. These methods were successfully applied through an iterative way and validated on CuCoNiZnMg and CuCoNiZnSnbased HEAs data. Finally, we successfully predicted adsorption energies of *H2CO (MAE: 0.24 eV) and *H3CO (MAE: 0.23 eV) by using the *HCO training data. Similarly, adsorption energy of *O (MAE: 0.32 eV) is also predicted from *H training data. We believe that our proposed method can shift the paradigm of state‐of‐the‐art ML in catalysis towards better interpretability. [ABSTRACT FROM AUTHOR]

The increasing levels of CO2 in the atmosphere due to anthropogenic activities pose a significant threat to the global climate. Conversion of CO2 to value-added chemicals such as methanol offers a promising approach for mitigating climate change while simultaneously generating useful products. This review paper provides a comprehensive overview of the synthesis and evaluation of nanocatalysts for CO2 hydrogenation to methanol. I will highlight the ongoing research and new advances being made in this field, including various catalyst materials, their preparation methods, and performance evaluations. I will also discuss the challenges and future perspectives in developing efficient and stable nanocatalysts for CO2 hydrogenation to methanol. [ABSTRACT FROM AUTHOR]

Methane, a potent greenhouse gas, has gained significant attention due to its environmental impact and economic potential. Chemical industries have focused on specialized catalytic systems, like zeolites, to convert methane into methanol. However, inherent limitations in selectivity, irreversibility, and pore blockages result in high costs and energy requirements, thus hindering their commercial viability and profitability. In contrast, biological methane conversion using methanotrophs has emerged as a promising alternative, offering higher conversion rates, self-renewability, improved selectivity, and economically feasible upstream processes. Nevertheless, biological methane oxidation encounters challenges including the difficulty in cultivating methanotrophs and their slow growth rates, which hinder large-scale bioprocessing. Another highlighted limitation is the limited mass transfer of methane into liquid in bioreactors. Practical strategies to enhance methane oxidation in biological systems, including optimizing reactor design to improve mass transfer, altering metal concentrations, genetic engineering of methane monooxygenases, enzyme encapsulation, and utilizing microbial consortia are discussed. By addressing the limitations of chemical approaches and highlighting the potential of biological methods, the review concluded that the utilization of genetically engineered methanotrophic biofilms on beads within a biotrickling reactor, along with enhanced aeration rates, will likely enhance methane oxidation and subsequent methane conversion rates.

Global energy demand has drastically increased due to urbanization and industrialization; thus, developing alternative renewable energy sources is urgently required. In the present work, upgrading the pyrolytic oil (PO) derived from fresh palm fruit was performed by the catalytic in situ hydrodeoxygenation (in situ HDO) process. Preparation of nickel-doped HZSM-5 zeolite (SiO2/Al2O3 = 40) was achieved by incipient wetness impregnation techniques using different weight percents of nickel dopant into HZSM-5. Nickel-doped HZSM-5 zeolite (Ni-HZSM-5) was further subjected to chemical reduction for 5 h in the oxygen-free environment (10% H2 and 90% N2) at 550 °C. The structural properties showed a potential reduction of NiO-HZSM-5 to Ni-HZSM-5, enhancing the catalytic potential. The morphological characterizations showed spherical-shaped Ni agglomerated onto HZSM-5. Acidity and oxygen contents in the pyrolytic oil were achieved by catalyst-aided HDO process at 220 °C for 6 h using methanol as a hydrogen donor. The catalytically upgraded pyrolytic oil (UPO) was analyzed for density, HHV, CHNO, and TGA. The best upgrading oil was distilled following ASTM D86 to separate gasoline, kerosene, and diesel. The acidity, density, HHV, and viscosity were measured before and after the upgradation processes. The results showed the potential impact of Ni with 10% doped on HZSM-5 on HDO reaction and illustrated the lowest oxygen content in upgraded pyrolytic oil products. Considerable decrease in viscosity and density level indicated that in situ HDO not only reduced oxygen content but also cracked pyrolytic oil to small molecules. The distilled product of upgrading oil was higher than pyrolytic oil by approximately 15% in volume. The viscosity, density, and HHV were under standard specifications of kerosene and diesel, except for acidity. However, the acidity was reduced by over 60% compared with raw material. [ABSTRACT FROM AUTHOR]

Tandem catalysis as an exciting research frontier has recently aroused wide attention due to the eliminated intermediate work-up, improved production efficiency, decreased production cost and reduced waste discharge. The main challenge in this tandem catalytic approach is the exploiting of a bifunctional catalyst that can be effective for both reactions processed under the same reaction conditions in a single reactor. We herein report for the first time that in the presence of in-situ generated Co3O4/CuCo2O4 heterostructures (CCHS) as a heterogeneous catalyst, α-methoxyphenylacetic acid (MTPAA) can be produced via tandem catalysis from styrene and methanol by integrating the styrene epoxidation and subsequent nucleophilic ring-opening of styrene oxide (SO). The styrene conversion of 94.8% accompanied with a selectivity of 62.5% to MTPAA was achieved under the optimal reaction conditions. Consequently, a simple heterogeneous approach for the highly efficient and selective production of MTPAA has been established. This study highlights the great potential of bifunctional heterostructures composed of earth-abundant elements for the synthesis of valuable chemicals via tandem conversion of styrene and subsequent diverse SO ring-opening reactions. In the presence of in-situ generated Co3O4/CuCo2O4 heterostructures as a heterogeneous catalyst, α-methoxyphenylacetic acid can be produced via tandem catalysis from styrene and methanol by integrating the styrene epoxidation and subsequent nucleophilic ring-opening of styrene oxide. [ABSTRACT FROM AUTHOR]

Quadrangular-pyramid-octahedral CeO2 with defects was successfully prepared and first used as effective and reusable heterogeneous catalyst for photo- and thermal- synergistic catalytic synthesis of DMC, and it showed better catalytic performance than that of thermocatalysis alone. The corner defects may be the active site based on experimental result and DFT calculation. The CeO2 with specific defects was prepared by PECVD method and first applied for photo-thermal synergistic catalytic synthesis of DMC from CO2 and methanol, which showed superior catalytic performance to that of thermocatalysis alone, and the active site maybe the corner defect. [ABSTRACT FROM AUTHOR]

Methane and carbon dioxide are the main contributors to global warming, with the methane effect being 25 times more powerful than carbon dioxide. Although the sources of methane are diverse, it is a very volatile and explosive gas. One way to store the energy content of methane is through its conversion to methanol. Methanol is a liquid under ambient conditions, easy to transport, and, apart from its use as an energy source, it is a chemical platform that can serve as a starting material for the production of various higher-value products. Accordingly, the transformation of methane to methanol has been extensively studied in the literature, using traditional catalysts as different types of zeolites. However, in the last few years, a new generation of catalysts has emerged to carry out this transformation with higher conversion and selectivity, and more importantly, under mild temperature and pressure conditions. These new catalysts typically involve the use of a highly porous supporting material such as zeolite, or more recently, metal-organic frameworks (MOFs) and graphene, and metallic nanoparticles or a combination of different types of nanoparticles that are the core of the catalytic process. In this review, recent advances in the porous supports for nanoparticles used for methane oxidation to methanol under mild conditions are discussed. [ABSTRACT FROM AUTHOR]

The development of 3d metal-catalyzed molecular transformations has been a key focus of research in recent decades. One significant advancement is the discovery of the homogenous iron, cobalt, and manganese-catalyzed (de)-hydrogenation processes. Among these redox transformations, the "Borrowing Hydrogen" (BH) principle, also known as hydrogen auto-transfer, stands out as an elegant and eco-friendly method that facilitates the self-transfer of hydrogen between reaction molecules and intermediates, eliminating the need for external hydrogen donors or acceptors. This concept allows for the eco-friendly use of alcohols, such as methanol, as environmentally benign C1 synthons for the alkylation of organic molecules, including pharmaceutically relevant candidates. In this context, the methyl group represents one of the most prevalent carbon fragments in smallmolecule drugs. In this book chapter, we summarize the discovery and recent advancements in the use of 3d metal complexes for (multi)methylation of organic compounds using methanol via the hydrogen borrowing methodology. Additionally, we discuss current limitations, challenges, and the future prospects of this field. [ABSTRACT FROM AUTHOR]

Rationally constructing atom‐precise active sites is highly important to promote their catalytic performance but still challenging. Herein, this work designs and constructs ZSM‐5 supported Cu and Ag dual single atoms as a proof‐of‐concept catalyst (Ag1−Cu1/ZSM‐5 hetero‐SAC (single‐atom catalyst)) to boost direct oxidation of methane (DOM) by H2O2. The Ag1−Cu1/ZSM‐5 hetero‐SAC synthesized via a modified co‐adsorption strategy yields a methanol productivity of 20,115 µmol gcat−1 with 81% selectivity at 70 °C within 30 min, which surpasses most of the state‐of‐the‐art noble metal catalysts. The characterization results prove that the synergistic interaction between silver and copper facilitates the formation of highly reactive surface hydroxyl species to activate the C−H bond as well as the activity, selectivity, and stability of DOM compared with SACs, which is the key to the enhanced catalytic performance. This work believes the atomic‐level design strategy on dual‐single‐atom active sites should pave the way to designing advanced catalysts for methane conversion. [ABSTRACT FROM AUTHOR]

The successful development and application in industry of methanol-to-olefins (MTO) process brought about an innovative and efficient route for olefin production via non-petrochemical resources and also attracted attention of C1 chemistry and zeolite catalysis. Molecular sieve catalysts with diversified microenvironments embedding unique channel/cavity structure and acid properties, exhibit demonstrable features and advantages in the shape-selective catalysis of MTO. Especially, shape-selective catalysis over 8-MR and cavity-type zeolites with acidic supercage environment and narrow pore opening manifested special host–guest interaction between the zeolite catalyst and guest reactants, intermediates and products. This caused great differences in product distribution, catalyst deactivation and molecular diffusion, revealing the cavity-controlled methanol conversion over 8-MR and cavity-type zeolite catalyst. Furthermore, the dynamic and complicated cross-talk behaviors of catalyst material (coke)-reaction-diffusion over these types of zeolites determines the catalytic performance of the methanol conversion. In this review, we shed light on the cavity-controlled principle in the MTO reaction including cavity-controlled active intermediates formation, cavity-controlled reaction routes with the involvement of these intermediates in the complex reaction network, cavity-controlled catalyst deactivation and cavity-controlled diffusion. All these were exhibited by the MTO reaction performances and product selectivity over 8-MR and cavity-type zeolite catalysts. Advanced strategies inspired by the cavity-controlled principle were developed, providing great promise for the optimization and precise control of MTO process. [ABSTRACT FROM AUTHOR]

Herein, we investigated the effect of indium promotion (0, 5, and 10%) on the physicochemical properties of Cu/ZrO2 catalysts, which were evaluated by several characterization techniques, and applied in the CO2 hydrogenation to methanol. The results showed that indium (In) was incorporated in the ZrO2 structure, which increased the oxygen vacancies and structural defects, increasing surface basicity and Cu relative content, leading these materials to present lower conversions but higher methanol selectivity. Mechanistic insights provided by in-situ DRIFTS analysis showed that the higher methanol selectivity of the In-promoted catalysts is also attributed to the ability of indium to take the CO2 hydrogenation mechanism through the formate intermediate as the preferential route, preventing CO formation and decreasing its selectivity. A chemometric approach was used to find the optimized temperature, pressure, and GHSV (456 K, 3 MPa, and 12 L.g−1.h−1) for CuZrIn5, leading to the higher methanol selectivity (~ 93%), with ~ 1.8% of conversion. [ABSTRACT FROM AUTHOR]

Methane, a potent greenhouse gas, has gained significant attention due to its environmental impact and economic potential. Chemical industries have focused on specialized catalytic systems, like zeolites, to convert methane into methanol. However, inherent limitations in selectivity, irreversibility, and pore blockages result in high costs and energy requirements, thus hindering their commercial viability and profitability. In contrast, biological methane conversion using methanotrophs has emerged as a promising alternative, offering higher conversion rates, self-renewability, improved selectivity, and economically feasible upstream processes. Nevertheless, biological methane oxidation encounters challenges including the difficulty in cultivating methanotrophs and their slow growth rates, which hinder large-scale bioprocessing. Another highlighted limitation is the limited mass transfer of methane into liquid in bioreactors. Practical strategies to enhance methane oxidation in biological systems, including optimizing reactor design to improve mass transfer, altering metal concentrations, genetic engineering of methane monooxygenases, enzyme encapsulation, and utilizing microbial consortia are discussed. By addressing the limitations of chemical approaches and highlighting the potential of biological methods, the review concluded that the utilization of genetically engineered methanotrophic biofilms on beads within a biotrickling reactor, along with enhanced aeration rates, will likely enhance methane oxidation and subsequent methane conversion rates. [ABSTRACT FROM AUTHOR]

The selective hydrogenation of CO2 to methanol by renewable hydrogen source represents an attractive route for CO2 recycling and is carbon neutral. Stable catalysts with high activity and methanol selectivity are being vigorously pursued, and current debates on the active site and reaction pathway need to be clarified. Here, we report a design of faujasite-encaged mononuclear Cu centers, namely Cu@FAU, for this challenging reaction. Stable methanol space-time-yield (STY) of 12.8 mmol gcat-1 h-1 and methanol selectivity of 89.5% are simultaneously achieved at a relatively low reaction temperature of 513 K, making Cu@FAU a potential methanol synthesis catalyst from CO2 hydrogenation. With zeolite-encaged mononuclear Cu centers as the destined active sites, the unique reaction pathway of stepwise CO2 hydrogenation over Cu@FAU is illustrated. This work provides a clear example of catalytic reaction with explicit structure-activity relationship and highlights the power of zeolite catalysis in complex chemical transformations. [ABSTRACT FROM AUTHOR]

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A synergetic catalytic system of organophotocatalyst 4CzIPN, thianthrene, and methanol was developed for visible‐light‐induced Giese reactions of various alkanes and alkenes, upon using alkoxy radicals as hydrogen atom transfer reagents. The reaction can be performed under mild conditions to provide the alkylated products in moderate to excellent yields, avoiding the use of any strong oxidants and transition metal reagents. Different from the known LMCT and PCET processes, the key to success of this approach is the in situ thianthrenation of methanol by thianthrene radical cation to trigger the generation of methoxy radical. [ABSTRACT FROM AUTHOR]

Mesoscopically structured ZSM‐5 nanosheets were prepared as highly active catalysts for the alkylation between toluene with methanol. The results showed that the Brønsted acid sites of ZSM‐5 nanosheets were mainly distributed on the external surface in aluminum‐rich zeolites owing to the charge‐balance between positive quaternary ammonium cation (N+) in Cph‐10‐6‐6, Na+ ions and negative aluminosilicate species. In addition, it revealed that high alkalinity was easier to depolymerize the SiOSi species in Aluminum‐rich synthesis gel, and the high alkalinity was required for silica‐rich systems to dissolve silica species in order to finish the self‐assemble process, leading to ZSM‐5 nanosheets with high alkalinity presenting enhanced catalytic performance. Moreover, the optimized ZSM‐5‐50‐2.5 was effective for the alkylation between toluene and methanol with toluene conversion of up to 50%, and it was stably operated for 48 h under the harsh conditions of WHSV = 32.5 h−1 with a desired stability. [ABSTRACT FROM AUTHOR]

To develop high-performance low-Pt electrocatalysts for direct alcohol fuel cells (DAFCs), we herein propose an interfacial engineering strategy, using interfacial Ag nanowire arrays as a sacrificing template and successfully fabricating a AgPtAu nanotrough array catalyst at water/air interfaces. By adjusting the conditions of interfacial reaction, composition-varied AgPtAu nanotrough arrays can be easily obtained. The formation of a trough-like morphology of AgPtAu can be attributed to the interface-confined Ag nanowire arrays reacting successively with PtCl62− and AuCl4− in the water phase. Optimized surface-Pt-rich Ag11Pt5Au84 nanotrough arrays exhibit ∼2270 and ∼2290 mA mgAu+Pt−1 in the mass activity towards methanol and ethanol electrooxidation, respectively, ∼3 times better than that of commercial Pt/C, and show improved tolerance towards CO-like carbonaceous intermediates. This work suggests that properly combining the positive catalytic effects of morphology and composition may be a possible avenue to tackle the issue of low-Pt electrocatalysts for DAFCs. [ABSTRACT FROM AUTHOR]

Copper-based zeolite catalysts are widely used in methanol synthesis from methane oxidation, but their photothermal catalytic properties have seldom been explored. This study examines the effect of the preparation method on Cu-based zeolite composite graphite-phase carbon nitride catalysts (Cu-MOR/g-C3N4) for direct methanol synthesis from methane oxidation by photothermal catalysis. Four different preparation methods are employed: liquid phase ion exchange (Cu-MOR/g-C3N4-IE), isovolumetric impregnation (Cu-MOR/g-C3N4-IM), solid-state ion exchange (Cu-MOR/g-C3N4-GR), and hydrothermal synthesis (Cu-MOR/g-C3N4-HT). Cu-MOR/g-C3N4-IE shows the highest methanol yield (3.09 μmol h−1 gcat−1) due to strong interactions between the CuxOy species and g-C3N4, as well as smaller interfacial charge transfer forces. This study provides a new method for the design and synthesis of catalysts for the conversion of methane. [ABSTRACT FROM AUTHOR]

Published papers highlight the roles of the catalysts in plasma catalysis systems, and it is essential to provide deep insight into the mechanism of the reaction. In this work, a coaxial dielectric barrier discharge (DBD) reactor packed with γ-MnO2 and CeO2 with similar nanorod morphologies and particle sizes was used for methanol oxidation at atmospheric pressure and room temperature. The experimental results showed that both γ-MnO2 and CeO2 exhibited good performance in methanol conversion (up to 100%), but the CO2 selectivity of CeO2 (up to 59.3%) was much higher than that of γ-MnO2 (up to 28.6%). Catalyst characterization results indicated that CeO2 contained more surface-active oxygen species, adsorbed more methanol and utilized more plasma-induced active species than γ-MnO2. In addition, in situ Raman spectroscopy and Fourier transform infrared spectroscopy (FT-IR) were applied with a novel in situ cell to reveal the major factors affecting the catalytic performance in methanol oxidation. More reactive oxygen species (O22−, O2−) from ozone decomposition were produced on CeO2 compared with γ-MnO2, and less of the intermediate product formate accumulated on the CeO2. The combined results showed that CeO2 was a more effective catalyst than γ-MnO2 for methanol oxidation in the plasma catalysis system. [ABSTRACT FROM AUTHOR]

Since WO3 is a relatively abundant metal oxide and features the ability to absorb in the visible spectrum, this non-toxic semiconductor is a promising photocatalyst among sustainable materials. These properties have delivered intriguing catalytic results in the conversion of methane to methanol; however, initial investigations indicate low photocatalytic efficiency resulting from fast recombination of photogenerated charges. To explore this aspect of inefficiency, five different morphologies of WO3 consisting of micron, nanopowder, rods, wires, and flowers were obtained and characterized. In addition, several electron capture agents/oxidizers were investigated as a means of improving the separation of photogenerated charges. The photocatalytic activity of different morphologies was assessed via CH3OH formation rates. Based on our results, WO3 flowers produced the highest methanol productivity (38.17 ± 3.24 µmol/g-h) when 2 mM H2O2 was present, which is approximately four times higher in the absence of H2O2. This higher methanol production has been attributed to the unique structure-related properties of the flower-like structure. Photoluminescence emission spectra and diffuse reflectance data reveal that flower structures are highly catalytic due to their reduced electron/hole recombination and multiple light reflections via petal-like hollow chambers. [ABSTRACT FROM AUTHOR]

Sufficient energy supply is increasingly becoming an important mechanism for catalyzing the development of a nation. A gradual shift to biofuels development was considered advantageous in reducing the pollution and other challenges associated with fossil fuels. Specifically, biodiesel production is one of those options prioritized in the literature. Herein, we demonstrated how a local rock sample can catalyze the upgrading of used groundnut oil into fuel-grade biodiesel at the laboratory scale via transesterification with methanol. The rock-based catalyst was characterized mainly to compose of oxides in the order SiO2 > Al2O3 > CaO > MgO > Fe2O3 with traces of Na2O, K2O, MnO and P2O5. The overall catalysis was believed to be initiated and aided by support, active sites participation and promotion effect. The optimum properties of 65oC, 6:1 (methanol: oil), moderate stirring and 100 mg catalyst loading were responsible for deriving 98.05% biodiesel yield. All the assessed fuel properties were also within the standard limits approved by ASTM. Thus, this suggests the feasibilities of the process parameters employed [ABSTRACT FROM AUTHOR]

Particulate methane monooxygenase (pMMO) is an enzyme that oxidizes methane to methanol with high activity and selectivity. Limited success has been achieved in incorporating biologically relevant ligands for the formation of such active site in a synthetic system. Here, we report the design and synthesis of metal-organic framework (MOF) catalysts inspired by pMMO for selective methane oxidation to methanol. By judicious selection of a framework with appropriate topology and chemical functionality, MOF-808 was used to postsynthetically install ligands bearing imidazole units for subsequent metalation with Cu(I) in the presence of dioxygen. The catalysts show high selectivity for methane oxidation to methanol under isothermal conditions at 150 °C. Combined spectroscopies and density functional theory calculations suggest bis(μ-oxo) dicopper species as probable active site of the catalysts.

The uncontrollable growth of CO2 concentration in the Earth atmosphere is a cause of ever-accelerating global warming. The warming up of the atmosphere and the increase in the partial pressure of CO2 induce multiple negative catastrophic phenomena on a global scale. On the other hand, carbon dioxide provides a unique and practically inexhaustible source of synthetic carbon (C1 synthon). Well-funded comprehensive studies of the processes of CO2 transformation into chemically important products, such as carboxylic acids, linear organic carbonates, urea and its derivatives, methanol, dimethyl ether, industrial gases (CO, methane), higher hydrocarbons, and products of fine organic synthesis, have been carried out in various countries for more than recent 20 years to mitigate CO2 emissions into the atmosphere. In Russia, this problem has remained virtually unnoticed. Therefore, in this review the authors set the task to draw the attention of chemists to the possibilities of using CO2 in synthesis and to the achievements that have been made in this area, particularly in the synthesis of hydroxybenzoic acids, methanol, and formic acid. [ABSTRACT FROM AUTHOR]

One of the effective methods of degradation and/or removal of chlorophenols, which are persistent environmental pollutants of toxic and resistant to biodegradation, is hydrodechlorination (HDC) via heterogeneous catalysis using liquid hydrogen donors. Here, Pd and Pd-M (M=Zn, Ni, Co) were supported on commercial multiwall carbon nanotubes (MWCNTs) and N-doped MWCNTs (N-MWCNTs), and their catalytic performances for the HDC of 2-chlorophenol (2-CP) using methanol as the hydrogen donor were investigated. The results showed that N-doping and/or the second metal addition to the N-MWCNTs supported Pd catalysts effectively increased their catalytic activity, which is attributed to the modulation of the Pd electronic structure and the improved active hydrogen supply from methanol by introducing the second metal. Particularly, nearly 100% conversion of 2-CP was achieved using Pd-Zn/N-MWCNTs. The catalysts were characterized using TEM, XPS, and XRD techniques to better understand the reaction mechanism, the promotional effects of N-doping in MWCNTs and the addition of second transition metal to the catalyst for the catalytic HDC of 2-CP. [Display omitted] • A liquid hydrogen donor of methanol was used for the catalytic HDC of 2-CP. • Pd and Pd-M (M=Zn, Ni, Co) @ N-MWCNTs were synthesized and used as catalysts. • Nearly 100% conversion of 2-CP was achieved on the Pd-Zn/N-MWCNTs catalyst. • The effects on HDC catalytic activity were studied. [ABSTRACT FROM AUTHOR]

A binary system (BS) of styrene epoxide–p-toluenesulfonic acid (SE–TSA) oxidized in a solution of isopropyl alcohol (ISA) initiates its radical chain oxidation (RCO). For the correct measurement of the oxygen uptake by the binary system itself, RCOs are blocked by introducing small (~10–5 mol/L) concentrations of Cu2+ acetate, a catalyst for breaking solvent oxidation chains. The oxidation rate measured using this technique is expressed as V = k [SE]0 [TSA]1 at [SE] [TSA]1, where SE is styrene epoxide and TSA is p‑toluenesulfonic acid. The Arrhenius form of the effective rate constant has the form k [s–1] = 5.2 × 1010exp(–85.0 kJ mol–1/RT) at 333–348 K. [ABSTRACT FROM AUTHOR]

• La incorporation into Cu–Ce for CO 2 hydrogenation to methanol. • La promoted the formation of smaller ceria crystallites. • Oxygen vacancy-rich Cu x /Ce y La 1-(x + y) O 2 -δ active domains were formed. The effect of La incorporation on the catalytic performance of Cu–CeO 2 for CO 2 hydrogenation to methanol was investigated. The increase of the CeO 2 lattice constant and shift in the F 2g band from Raman spectroscopy confirmed La incorporation into the CeO 2 lattice. The La atomic percent of ≤ 19 % was the upper limit for the amount of La incorporated fully into the CeO 2 lattice without any phase segregation. XPS results of Cu 0.25 Ce 0.56 La 0.19 O 2-δ assumed to have full La incorporation, showed a maximum concentration of oxygen vacancies that facilitated CO 2 adsorption and conversion to methanol. The lattice fringes from HRTEM and lattice expansion confirmed that Cu was located on the catalyst surface for the synthesized catalysts. Cu 0.25 Ce 0.56 La 0.19 O 2-δ showed an improvement in the methanol space-time yield when the temperature was increased from 260 °C to 280 °C, in contrast to the catalysts with excess La on the surface. The descriptors for the methanol production were the availability of oxygen vacancies and the metal-metal oxide interaction (Cu–Ce x La 1−x O 2-δ and Cu–La 2 O 2 CO 3). The smaller metallic Cu crystallite size for Cu 0.25 Ce 0.19 La 0.56 O 2-δ suggested increased interactions between Cu0 and the Ce x La 1−x O 2-δ support, which was conducive for methanol formation. The highest performance of Cu 0.25 Ce 0.56 La 0.19 O 2-δ at a higher temperature of 280 °C and pressure of 50 bar with a methanol space-time yield of 55.2 g CH3OH.kg catal.h−1 was attributed to the excellent thermal stability of the formed Ce x La 1−x O 2-δ solid solution support interacting with Cu which prevented sintering. [Display omitted] [ABSTRACT FROM AUTHOR]

• Synthesizing Pt-Cu@CeO 2 /MWCNTs electrocatalysts used for methanol oxidation. • The mass activity of the Pt–Cu@CeO 2 /MWCNTs was 4.40 times that of the Pt–MWCNTs. • Detection of intermediates using in-situ Raman. • Mechanistic analysis was performed using density functional theory calculations. Achieved by introducing defect sites, enhances both the catalytic activity and stability of catalysts. This is crucial for advancing key applications in energy conversion and environmental protection. Here, we introduce a novel Pt-Cu@CeO 2 /MWCNTs electrocatalyst prepared by dual modulation of the oxygen vacancy anchoring point and the center of the alloying d-band. This catalyst significantly boosts the rate of methanol oxidation. The Pt-Cu@CeO 2 /MWCNTs catalyst demonstrates a mass activity 3.7 times higher than that of commercial Pt/C, along with exceptional durability. The electron transfer between the PtCu alloy and the oxygen vacancies effectively modulates the d-band center of Pt, leading to a "volcano" relationship between the catalyst's mass activity and the d-band center. This study advances the development of methanol electrooxidation catalysts by introducing a novel "double enhancement effect" model. [ABSTRACT FROM AUTHOR]

• This review focused on thermocatalytic hydrogenation of CO 2 to methanol over heterogeneous catalysts, including Cu-based and indium oxide-based catalysts. • The mechanism of methanol synthesis over the Cu-based catalysts were discussed, especially for the elementary reactions for the formate and carboxylic mechanisms. • The prospects for the commercialization of the process of CO 2 hydrogenation to produce methanol were also presented. Carbon dioxide utilization is considered among priority tasks for sustainability. One of the hot topics is the process of CO 2 hydrogenation to produce methanol. Both thermocatalytic and electrocatalytic methods, as well as photocatalytic conversion have been proposed. In this review, we provide a survey of recent literature on thermocatalytic hydrogenation of CO 2 to methanol over heterogeneous catalysts. The main focus was made on the influence of the catalyst compositions, nature of the supports and process conditions on the selectivity and productivity of the process. [Display omitted] [ABSTRACT FROM AUTHOR]

Glycerol, a highly functionalised polyol, can be used as a platform molecule to produce a variety of high-value chemicals. As glycerol production is projected to increase over the coming years, it's critically important that technology and infrastructure are developed to make use of the inevitable surplus. The catalytic production of 'green' mono alcohols from glycerol, in the absence of H2, is an emerging area of research that, in recent years, has generated significant industrial interest. Herein, we provide an update on recent advances in this field and discuss challenges which need to be overcome if this approach is to be considered viable industrially. The economic significance of using crude glycerol as a feedstock for glycerol valorisation strategies is also addressed and suggestions for improving the impact of research conducted in this field are proposed. [ABSTRACT FROM AUTHOR]

Methane is one of the promising alternatives to non-renewable petroleum resources since it can be transformed into added-value hydrocarbon feedstocks through suitable reactions. The conversion of methane to methanol with a higher chemical value has recently attracted much attention. The selective oxidation of methane to methanol is often considered a "holy grail" reaction in catalysis. However, methanol production through the thermal catalytic process is thermodynamically and economically unfavorable due to its high energy consumption, low catalyst stability, and complex reactor maintenance. Photocatalytic technology offers great potential to carry out unfavorable reactions under mild conditions. Many in-depth studies have been carried out on the photocatalytic conversion of methane to methanol. This review will comprehensively provide recent progress in the photocatalytic oxidation of methane to methanol based on materials and engineering perspectives. Several aspects are considered, such as the type of semiconductor-based photocatalyst (tungsten, titania, zinc, etc.), structure modification of photocatalyst (doping, heterojunction, surface modification, crystal facet re-arrangement, and electron scavenger), factors affecting the reaction process (physiochemical characteristic of photocatalyst, operational condition, and reactor configuration), and briefly proposed reaction mechanism. Analysis of existing challenges and recommendations for the future development of photocatalytic technology for methane to methanol conversion is also highlighted. [ABSTRACT FROM AUTHOR]

Herein, we report a two‐step strategy for the preparation of vertex‐type‐selectively reinforced PtCu@PtCuNi double‐layered nanoframes (DNFs). In the first step, PtCuNi heterogeneous nanocrystals (HNCs) were synthesized by a facile one‐pot solvent method. The PtCuNi HNC is composed of a Cu‐enriched concave rhombic dodecahedral core, a double‐layered nanoframe consisting of an inner vertex‐selectively‐reinforced rhombic dodecahedral PtCu nanoframe and an outer concave rhombic dodecahedral PtCuNi nanoframe, and a Ni‐enriched shell. In the second step, PtCu@PtCuNi DNFs were prepared by selectively removing the leachable components via acid treatment. Strikingly, the inner rhombic dodecahedral nanoframe contained six nanopods sticking out from its ⟨100⟩ vertices rather than ⟨111⟩ ones, and the outer concave rhombic dodecahedral nanoframe is formed by interconnecting the adjacent vertices of the inner nanoframe. The electrocatalytic test for methanol oxidation reaction showed that the as‐prepared PtCu@PtCuNi DNFs exhibited enhanced electrocatalytic activity and improved stability compared to the commercial Pt/C catalyst. [ABSTRACT FROM AUTHOR]