Formation Of CO Research Articles

CO‐tolerant heterogeneous ruthenium catalysts for efficient formic acid dehydrogenation

The development of improved and less costly catalysts for dehydrogenation of formic acid (HCOOH) is of general interest for renewable energy technologies involving hydrogen storage and release. Theoretical calculations reveal that ruthenium (Ru) nanoparticles supported on nitrogen‐doped carbon should be appropriate catalysts for such transformations. It is predicted that nitrogen doping significantly decreases the formation of CO, but at the same time increases CO tolerance of the catalysts. To prove these hypotheses heterogeneous ruthenium catalysts supported on porous nitrogen‐doped carbon (Rux/CN) with hierarchical structure were synthesized using carbon nitride (C3N4) as template and phenanthroline (Phen) as ligand. Experimental tests in HCOOH dehydrogenation revealed the optimal catalyst Ru7/CN exhibiting good thermal stability and a high turnover frequency (TOF > 1300 h‐1), which is more than one order of magnitude higher than that of the commercial Ru5/C catalyst.

CO-tolerant heterogeneous ruthenium catalysts for efficient formic acid dehydrogenation.

The development of improved and less costly catalysts for dehydrogenation of formic acid (HCOOH) is of general interest for renewable energy technologies involving hydrogen storage and release. Theoretical calculations reveal that ruthenium (Ru) nanoparticles supported on nitrogen-doped carbon should be appropriate catalysts for such transformations. It is predicted that nitrogen doping significantly decreases the formation of CO, but at the same time increases CO tolerance of the catalysts. To prove these hypotheses heterogeneous ruthenium catalysts supported on porous nitrogen-doped carbon (Rux/CN) with hierarchical structure were synthesized using carbon nitride (C3N4) as template and phenanthroline (Phen) as ligand. Experimental tests in HCOOH dehydrogenation revealed the optimal catalyst Ru7/CN exhibiting good thermal stability and a high turnover frequency (TOF > 1300 h-1), which is more than one order of magnitude higher than that of the commercial Ru5/C catalyst.

Study on the reaction mechanism and kinetics of limestone hydrogenation by micro fluidized bed: Effect of H2 concentration and natural limestone

Limestone decomposition is the first step in cement production, which produces a significant amount of CO2 and poses a significant challenge to achieve carbon neutrality. Hydrogenation of limestone can produce CO or CH4 instead of CO2, which can be considered as a new way of carbon capture, making it a promising method for carbon emission reduction. In this work, pure CaCO3 and several natural limestone samples were hydrolyzed under varying H2 concentration using a micro fluidized bed (MFB) reactor combined with online mass spectrometry to reveal the mechanism and kinetics of limestone hydrogenation.The main gases produced by hydrogenation at 1 atm are CO and CO2. The CO2 comes from the calcination of CaCO3. The CO comes from 2 steps: the first step is the in-situ hydrogenation of CaCO3 and the second step is the Reverse Water Gas Shift (RWGS) reaction. The activation energy (Ea) of CO2 formation in H2 atmosphere is lower than in Ar atmosphere. However, there is no obvious effect of different H2 concentrations on the Ea of CO2 formation. The Ea of CO in situ formation is 72.70 KJ/mol, 54.53 KJ/mol, 71.34 KJ/mol and 60.29 KJ/mol in 10%, 30%, 50% and 70% H2 atmosphere, respectively. The H2 concentration also has no significant effect on the in-situ CO evolution. However, the H2 concentration can affect the Ea of CO produced by RWGS. The Ea is 75.67 KJ/mol, 167.59 KJ/mol and 221.47 KJ/mol in 10%, 30% and 50% H2 atmosphere, and this reaction doesn't occur in 70% H2 atmosphere. Compared with the pure CaCO3, the hydrogenation of limestone can produce more CO and less CO2. In limestone, impurity elements are the main factor affecting the reaction kinetics. Transition metals can increase the rate of CO2 production, but have no apparent effect on CO. The CO2 yield of high impurity limestone is higher than that of limestone with low impurities. Transition metals can also reduce the Ea of CO2 formation and the RWGS reaction. In the 50% H2 atmosphere, the Ea of CO2 formation is 88.87 KJ/mol and the Ea of CO from RWGS is 137.60 KJ/mol. However, under the same conditions, the Ea of pure CaCO3 is 126.91 KJ/mol and 221.47 KJ/mol.

Theoretical research of the NO and N2O reduction by char in oxy-fuel CFBC: Influence of H2O

Oxy-fuel CFBC has lower NOx emissions compared to air combustion, with the high H2O content affecting NO and N2O reduction. This study, using density functional theory and transition state theory, investigates the impact of H2O on the char model at the electronic level and its subsequent influence on NO and N2O reduction. Results reveal that H2O adsorbs onto the active site on char, forming hydroxyl groups and free H atoms. The unstable O atom in –OH group leads to benzene ring rearrangement in the char model, creating additional active sites. NO reduction follows two paths: producing CO(R1) or CO2(R2). For N2O reduction(R3), N2O reduction precedes benzene ring cracking, with CO2 production providing more active sites. In R1, CO formation limits reactive sites and increases activation energy, while R2 and R3 favor CO2 formation. Reaction pathways leading to CO2 formation show lower activation energies and higher pre-exponential factors for N2 release.

Tuning microenvironment of Bi2O3 nanosheets via Ce doping for promoting CO2 electrolysis to formate

The precise tuning of the electrocatalytic surface microenvironment for CO2 adsorption and conversion is essential for an efficient electrocatalytic CO2 reduction reaction (eCO2RR); however, it constitutes a challenging task. In this work, Ce-doped Bi2O3 nanosheets with enhanced Bi oxidation and abundant oxygen vacancies have been developed as an efficient electrocatalyst for the eCO2RR. The synthesized Ce/Bi2O3 nanosheet electrocatalyst achieves a Faraday efficiency above 90 % for formate production within a wide potential window from −0.8 to −1.1 V (versus RHE). The Ce dopant as an electron acceptor modifies the electronic structure of the Bi sites, enhancing the CO2 adsorption and promoting the formation of CO2•−. Moreover, Ce doping provides a local high pH and accelerates the proton-electron transfer process of *OCHO intermediates. This work provides new insights into the formation of a highly active reaction zone at the gas–liquid–solid interface for establishing a favorable microenvironment and further promoting an efficient eCO2RR.

GEOLOGICAL CONDITIONS OF FORMATION AND DISTRIBUTION OF GAS-GEOCHEMICAL FIELDS IN BOTTOM SEDIMENTS OF THE LAPTEV-SIBERIAN SEA ZONE OF THE EAST ARCTIC SHELF

Gas composition of bottom sediments of the Laptev-Siberian Sea geostructural zone (LSZ) was determined to include: helium and hydrogen in concentrations of 0.0028–0.2092 and 0.0012–0.8727 cm3/kg, hydrogen sulfide – 0.0006–0.0072, carbon monoxide – 0.0016–0.0577, carbon dioxide – 0.1482–21.1602, methane – 0.0017–8.3047 and its homologues (in total) – 0.00001–0.0355 cm3/kg. It was found that the values of average concentrations of gases in bottom sediments increase with the depth of their occurrence and exceed the anomaly criteria identified for the East Arctic shelf by 2.6–27.7 times, including: CO2, CO and H2S – by 2.6, 3.0 and 3.4 times, ΣC2–C5 and He – by 9.3 and 10.8 times, CH4 – by 27.7 times; this actually indicates a high degree of gas saturation of bottom sediments of the region. The formation of CO2, CO, H2S, H2, CH4 and ΣC2–C5 anomalies in sediments of the upper and the base of the middle sampling horizon is determined by relatively high contents of sapropelic and humic organic matter and gas influx from the lower horizon. Distribution of anomalies with maximum concentrations of natural gases and He in sediments of the lower horizon, with minimum contents of Corg, is associated with zones of faults, large dislocations, tectono-magmatic and seismic activity, which are the main routes of diffusion-migration of gas transfer to bottom sediments. Formation of concentrations of gases and their anomalies in sediments of the LSZ follows the rules of additivity, i.e. successive accumulation of migratory natural gases of different genesis with prevalence of gas phase and isotopic indicators of more gas-saturated parental source, epigenetic and syngenetic to sediments. It was found that maximum values of average gas saturation with CH4, ΣС2–С5, He and H2 in LSZ are typical for bottom sediments of the flanks of troughs, CO and CO2 – for the arch parts of uplifts. In sediments of monoclinal folds (structural terraces), minimal values of average gas saturation are observed, with the exception of the South Anyui Fault Zone. In general, gas saturation of LSZ sediments is determined by the complex impact of geological factors, with the major ones being: gas content of rock complexes and gas saturation of underlying sediments, fault and fold tectonics, a high degree of tectono-magmatic and seismic activity, a geostructural position, coal content, oil and gas content, as well as the depth of occurrence, organic saturation and material composition of OM in bottom sediments. The influence of the latter predetermined the formation and distribution of five geochemical fields of CH4, three of CO, ΣС2–С5, He and one of CO2, and one of H2 in LSZ.

Preparation of Bi2WO6/MXene(Ti3C2Tx) Composite Material and Its Photothermal Catalytic Reduction of CO2 in Air

In response to growing concerns about the greenhouse effect, the direct conversion of atmospheric CO2 has become a pivotal research focus. This research utilizes hydrothermal synthesis to develop Bi2WO6/MXene(Ti3C2Tx), which efficiently reduces CO2 directly at the gas–solid interface through photothermal synergy, without requiring additional sacrificial agents or alkaline absorption solutions. The results indicate that the CO formation rate is about 216.9 μmol·g−1h−1. Notably, this system demonstrates exceptional selectivity for reducing CO2 to CO. The outstanding photothermal catalytic efficiency is attributed to the introduction of MXene, which serves as an efficient and economical co-catalyst. The integration of MXene improves the composite material’s specific surface area and pore structure, enhances its CO2 adsorption capacity, and results in the Bi2WO6/MXene hybrid having a shorter charge transfer distance and a larger interface contact area. This ensures superior charge transfer capabilities, ultimately leading to a significant enhancement in the catalytic efficiency of the composite. This study presents a straightforward and highly selective method for capturing and converting atmospheric CO2, offering fresh insights for developing efficient photothermal catalytic materials.

All-in-One CO2 Capture and Transformation: Lessons from Formylmethanofuran Dehydrogenases.

ConspectusCarbon-one-unit (C1) feedstocks are generally used in the chemical synthesis of organic molecules, such as solvents, drugs, polymers, and fuels. Contrary to the dangerous and polluting carbon monoxide mostly coming from fossil fuels, formate and formamide are attractive alternative feedstocks for chemical synthesis. As these are currently mainly obtained from the oil industry, novel synthetic routes have been developed based on the transformation of the greenhouse gas CO2. Such developments are motivated by the urgent need for carbon chemical recycling, leading to a sustainable future. The inert nature of CO2 represents a challenge for chemists to activate and specifically convert the molecule through an affordable and efficient process. The chemical transformation could be inspired by biological CO2 activation, in which highly specialized enzymes perform atmospheric CO2 fixation through relatively abundant metal catalysts. In this Account, we describe and discuss the potential of one of the most efficient biological CO2-converting systems: the formylmethanofuran dehydrogenase (abbreviated as FMD).FMDs are multienzymatic complexes found in archaea that capture CO2 as a formyl group branched on the amine moiety of the methanofuran (MFR) cofactor. This overall reaction leading to formyl-MFR production does not require ATP hydrolysis as compared to the CO2-fixing microbes relying on the reductive Wood-Ljungdahl pathway, highlighting a different operative mode that saves cellular energy. FMD reaction represents the entry point in hydrogenotrophic methanogenesis (H2 and CO2 dependent or formate dependent) and operates in reverse in other methanogenic pathways and microbial metabolisms. Therefore, FMD is a key enzyme in the planetary carbon cycle. After decades of investigations, recent studies have provided a description of the FMD structure, reaction mechanism, and potential for the electroreduction of CO2, to which our laboratory has been actively contributing.FMD is an "all-in-one" enzyme catalyzing a redox-active transformation coupled to a redox-neutral transformation at two very different metal cofactors where new C-H and C-N bonds are made. First, the principle of the overall reaction consisting of an exergonic CO2 reduction coupled with an endergonic formate condensation on MFR is resumed. Then, this Account exposes the molecular details of the active sites and provides an overview of each catalytic mechanism. It also describes the natural versatility of electron-delivery modules fueling CO2 reduction and extends it to the possibilities of using artificial systems such as electrodes.A perspective concludes on how the mechanistic of FMD could be applied to produce CO2-based chemical intermediates to synthesize organic molecules. Indeed, through its biochemical properties, the enzyme opens opportunities for CO2 electroreduction to generate molecules such as formate and formamide derivatives, which are all intermediates for synthesizing organic compounds. Transferring the chemical knowledge acquired from these biological systems would provide coherent models that can lead to further development in the field of synthetic biology and bio-inspired synthetic chemistry to perform large-scale CO2 conversion into building blocks for chemical synthesis.

Ce-modified Cu nanoparticles with N-doped carbon encapsulation for efficient H2 production from aqueous phase reforming of methanol at low temperatures

Aqueous-phase reforming of methanol (APRM) for both hydrogen (H2) production and high pressure storage shows promising potential in mobile/distributed fuel cell stations or vehicles. Currently, achieving efficient H2 production with low CO selectivity (S-CO) at lower temperatures remains a challenge for its application in these fields (rapid start and running in cycles). Herein, the catalyst of Ce-modified Cu nanoparticles with N-doped carbon encapsulation (Cu-CeO2@PVP catalyst) is developed to give excellent H2 production rate at low temperatures ranging from 110 °C to 180 °C, ensuring excellent hydrothermal stability. The H2 production rate of 32.56 μmol·gcat-1·s−1 at 180 °C is 6.1 times to 10.2 times higher than those of commercial catalysts, which demonstrates its superior performance. The combined effect of Cu+/Cu0 and CeO2 promotes the H2 production from CH3OH/H2O. It also suppresses the CO formation by enhancing the H2O dissociation, CO conversion and HCOOH decomposition in APRM. The stable high purified H2 flow from the integrated slurry bed APRM device can start immediately the fuel cell vehicle without any delay.

Proposed Importance of HOCO Chemistry: Inefficient Formation of CO2 from CO and OH Reactions on Ice Dust

With the advent of JWST ice observations, dedicated studies on the formation reactions of detected molecules are becoming increasingly important. One of the most interesting molecules in interstellar ice is CO2. Despite its simplicity, the main formation reaction considered, CO + OH → CO2 + H through the energetic HOCO* intermediate on ice dust, is subject to uncertainty because it directly competes with the stabilization of HOCO as a final product, which is formed through energy dissipation of HOCO* to the water ice. When energy dissipation to the surface is effective during the reaction, HOCO can be a dominant product. In this study, we experimentally demonstrate that the major product of the reaction is indeed not CO2, but rather the highly reactive radical HOCO. The HOCO radical can later evolve into CO2 through H-abstraction reactions, but these reactions compete with additional reactions, leading to the formation of carboxylic acids (R-COOH). Our results highlight the importance of HOCO chemistry and encourage further exploration of the chemistry of this radical.

Carbon Dot Micelles Synthesized from Leek Seeds in Applications for Cobalt (II) Sensing, Metal Ion Removal, and Cancer Therapy.

Popular photoluminescent (PL) nanomaterials, such as carbon dots, have attracted substantial attention from scientists due to their photophysical properties, biocompatibility, low cost, and diverse applicability. Carbon dots have been used in sensors, cell imaging, and cancer therapy. Leek seeds with anticancer, antimicrobial, and antioxidant functions serve as traditional Chinese medicine. However, leek seeds have not been studied as a precursor of carbon dots. In this study, leek seeds underwent a supercritical fluid extraction process. Leek seed extract was obtained and then carbonized using a dry heating method, followed by hydrolysis to form carbon dot micelles (CD-micelles). CD-micelles exhibited analyte-induced PL quenching against Co2+ through the static quenching mechanism, with the formation of self-assembled Co2+-CD-micelle sphere particles. In addition, CD-micelles extracted metal ion through liquid-liquid extraction, with removal efficiencies of >90% for Pb2+, Al3+, Fe3+, Cr3+, Pd2+, and Au3+. Moreover, CD-micelles exhibited ABTS•+ radical scavenging ability and cytotoxicity for cisplatin-resistant lung cancer cells. CD-micelles killed cisplatin-resistant small-cell lung cancer cells in a dose-dependent manner with a cancer cell survival rate down to 12.8 ± 4.2%, with a similar treatment function to that of cisplatin. Consequently, CD-micelles functionalized as novel antioxidants show great potential as anticancer nanodrugs in cancer treatment.

Constructing Ag/Cu2O Interface for Efficient Neutral CO2 Electroreduction to C2H4

AbstractNeutral CO2 electroreduction to multi‐carbons (C2+) offers a promising pathway to reduce the CO2 and energy losses originating from the carbonate formation. However, the sluggish kinetics of C−C coupling brings a significant challenge of achieving high selectivity of a single product (such as ethylene), especially at industrial‐relevant current densities (>300 mA cm−2). Here, we reported an optimized Ag‐Cu2O interfacial catalyst that exhibited C2+ Faradaic efficiency (FE) of 73.6 % at 650 mA cm−2 in a flow cell. Remarkably, it obtained FEC2H4 of 66.0 % with a partial current density of 429.1 mA cm−2, making it stand out among the reported Cu‐based electrocatalysts. In situ Raman spectra uncovered that the Ag/Cu2O interfaces enabled a high coverage of *CO around the partially reduced Cu+/Cu0 active sites. Furthermore, theoretical calculations demonstrated the enhanced CO formation and C−C coupling at the Ag/Cu2O interface. This work reported an unprecedented neutral CO2 electroreduction to C2H4 performance and provided an in‐depth comprehension of the role of the bimetallic interface.

Scattering of CO from Vacant-MoSe2 with O Adsorbates: Is CO2 Formed?

Using ab initio molecular dynamics (AIMD) simulations, based on density functional theory that also accounts for van der Waals interactions, we study the oxidation of gas-phase CO on MoSe2 with a Se vacancy and oxygen coverage of 0.125 ML. In the equilibrium configuration, one of the O atoms is adsorbed on the vacancy and the other one atop one Se atom. Recombination of the CO molecule with the second of these O atoms to form CO2 is a highly exothermic reaction, with an energy gain of around 3 eV. The likeliness of the CO oxidation reaction on this surface is next examined by calculating hundreds of AIMD trajectories for incidence energies that suffice to overcome the energy barriers in the entrance channel of the CO oxidative recombination. In spite of this, no CO2 formation event is obtained. In most of the calculated trajectories, the incoming CO molecule is directly reflected, and in some cases, mainly at low energies, the molecules remain trapped at the surface but without reacting. As an important conclusion, our AIMD simulations show that the recombination of CO molecules with adsorbed O atoms is a very unlikely reaction in this system, despite its large exothermicity.

Silver Electrodes Are Highly Selective for CO in CO2 Electroreduction due to Interplay between Voltage Dependent Kinetics and Thermodynamics.

Electrochemical reduction is a promising way to make use of CO2 as feedstock for generating renewable fuel and valuable chemicals. Several metals can be used as the electrocatalyst to generate CO and formic acid, but hydrogen formation is an unwanted side reaction that can even be dominant. The lack of selectivity is, in general, a significant problem, but silver-based electrocatalysts have been shown to be highly selective, with faradaic efficiency of CO production exceeding 90%, when the applied voltage is below -1 V vs RHE. In this voltage range, only a small amount of hydrogen and formate is formed. We present calculations of the activation free energy for the various elementary steps as a function of applied voltage at the three low index facets, Ag(111), Ag(100) and Ag(110), as well as experimental measurements on polycrystalline electrodes, to identify the reason for this high selectivity. The formation of formic acid is suppressed, even though it is thermodynamically favored, because of the low coverage of adsorbed hydrogen and kinetic hindrance to the formation of the HCOO* intermediate, while *COOH, a key intermediate in CO formation, is thermodynamically unstable until the applied voltage reaches -1 V vs RHE, at which point the kinetics for its formation are more favorable than for hydrogen. The calculated results are consistent with experimental measurements carried out for acidic conditions and provide an atomic scale insight into the high CO selectivity of silver-based electrocatalysts.

Engineering Co Single Atoms in Ultrathin BiOCl Nanosheets for Boosted CO2 Photoreduction

AbstractDespite the development of a range of photocatalysts for CO2 reduction, the practical applications are significantly limited by low conversion efficiencies and their reliance on sacrificial agents, which are rooted in thermodynamic and kinetic challenges related to CO2 conversion. Here, the engineering of Co single atoms in ultrathin single‐crystal BiOCl nanosheets for boosted photocatalytic CO2 reduction is reported. The engineering of Co atoms modulates the distribution of photogenerated charges at the catalyst surface, controlling key surface reaction dynamics and suppressing surface electron‐hole recombination. This modulation also improves light absorption and enhances CO2 adsorption and activation, leading to more efficient surface reactions. Notably, CO2 is stably adsorbed onto the (001) face of BiOCl through a Bi‐O‐C(= O)‐Co‐O coordination unit, which lowers the activation energy for CO2 reduction and reduces the formation energy of COOH− intermediates. As a result, the BiOCl photocatalysts achieve a CO formation rate of 183.9 µmol g−1 h−1, when irradiated with a 300 W Xe lamp without cocatalysts or sacrificial agents. It represents an ≈13‐fold increase compared to that of pristine BiOCl, and surpasses most reported Bi‐based photocatalysts to date. Current work provides valuable insights into engineering of single atoms for developing advanced CO2‐reduction photocatalysts.

Deciphering the reaction network for the acetoxylation of propylene to allyl acetate on PdCu catalysts combined DFT with kMC analysis

The acetoxylation of propylene to allyl acetate on PdCu catalysts is a critical step in the Lyondell method for BDO production. By combining Density Functional Theory and kinetic Monte Carlo simulations, the reaction network and the formation pathways of allyl acetate and CO2 were systematically studied. Propylene and acetic acid were both activated by oxygen-assisted dehydrogenation to obtain CH3COO* and CH2CHCH2*, which would participate in the C-O coupling reaction to form allyl acetate, with the apparent activation energy of 0.64 eV. Besides, the dominant paths for the formation of CO2 from the complete oxidation of propylene and acetic acid were identified with the apparent activation energy of 1.80 eV. As the temperature rises, the TOF of allyl acetate and CO2 formation increase gradually, while the molar fraction of allyl acetate in the products decreases, indicating that temperature exerts a greater influence on the formation of CO2 than allyl acetate.

Analysis of thermoacoustic instability and emission behaviors of lean premixed biogas/ammonia flame

Ammonia and biogas are promising renewable fuels that can reduce carbon emissions. This paper studies thermoacoustic instability and emission behaviors of biogas/ammonia co-firing swirl flame. The effects of CO2 proportion in biogas (), ammonia proportion () and equivalence ratio (Φ) on combustion characteristics were considered. A chemical reactor network (CRN) was established to advance comprehension regarding NO emission. The results show that high Φ and are more conducive to simultaneously suppressing thermoacoustic instability and NO emissions. Lower flame appears to have intense thermoacoustic instability when Φ near 0.90, and the instability intensity is significantly weakened when exceeds 20%. The CO2 in the mixture inhibits NO formation but promotes CO formation. The CRN results show that CO2 in biogas reduces NO emissions by inhibiting the HNO pathway and promoting the NHi pathway. This study furnishes a foundation for advancing clean and efficient low-carbon combustion systems.

Conversion of C4F8 via plasma catalysis over Al2O3/Zr/SO4-2 catalyst: Effects of H2O(g)

Reducing the emission of octafluorocyclobutane (C4F8) which has a high global warming potential (GWP) of 10,300 is essential. This study investigated the effectiveness of C4F8 removal achieved with plasma catalysis system. Effects of Ar content in the gas stream and inlet C4F8 concentration on C4F8 conversion efficiency were evaluated with two types of catalysts including Al2O3 (A) and Al2O3 /ZrO2/SO42-(AZS). Results demonstrated a linear correlation between Ar content with C4F8 conversion, and energy efficiency (EE). Lissajous figure analysis coupled with BOLSIG + simulations revealed that the AZS catalyst applied increased the mean electron energy (MEE) to 2.68 eV and modified the electron energy distribution function (EEDF), likely contributing to its superior performance. At a C4F8 concentration of 400 ppm, the AZS catalyst coupled with plasma achieved 80 % conversion with an EE of 1.85 g/kWh. Interestingly, at an optimal inlet C4F8 concentration of 5,000 ppm, the highest EE (11 g/kWh) was obtained with a C4F8 conversion efficiency of 18 %. The addition of H2O(g) as a reactant resulted in complete C4F8 conversion when AZS catalyst was applied. The optimal plasma-catalytic conditions determined through C4F8 conversion, EE and CO2 equivalent (CO2e) assessments, yielded a CO2e emission (CO2e) to CO2 reduction (CO2r) ratio of 1:9.09. Product analysis revealed the formation of CO2, CO, and HF during C4F8 conversion with AZS catalyst in the presence of H2O(g). The system was operated at 12 kV for the gas stream containing 50 % Ar and N2 as carrier gas at a flow rate of 100 mL/min. These findings highlight the potential of plasma catalysis for the effective abatement of C4F8, offering a promising strategy for mitigating its environmental impact.

Mild-Condition Photocatalytic Reforming of Methanol-Water by a Hierarchical, Asymmetry Carbon Nitride.

As a reproducible intermediate for hydrogen (H2) and carbon cycling, methanol mixed with water (H2O) in a ratio of 1 : 1 can multiply the outcome of green H2 generation via Photocatalytic reforming of methanol-H2O (PRMW). Hitherto, low-energy and mild-condition PRMW remains a serious challenge. Here, the amino acid-derived carbon nitrides (ACN) were synthesized supramolecular precursor strategy for PRMW and achieved excellent performance (H2, 35.6 mmol h-1 g-1; CO2, 11.5 mmol h-1 g-1) under sunlight at 35 °C. It was revealed that the surface-terminating carboxyl groups (-COOH) promote the dark dehydrogenation of methanol on MetCNx to form methoxy (*OCH3) and methylol (*CH2OH) simultaneously, with the hydroxyl (*OH) generated by photostimulated H2O oxidation promotes the C-H activation of formaldehyde, then leads the whole reaction into the formation of CO2 and three H2. The extended light absorption, enhanced charge separation and transport, and efficient surface reaction improve photocatalytic efficiency.

An Atomic-scale Explanation For The High Selectivity Towards Carbon Dioxide Reduction Observed On Liquid Metal Catalysts.

The low-temperature liquid metals Ga-In and Ga-Snhave previously showcased >95% selectivity towards the electrochemical reduction of CO2to formate, occuring only when the alloys are melted, not solid.Here, density functional theory molecular dynamics and metadynamics simulations reveal that CO2does not directly adsorb to the Ga-alloy surface, but instead is reduced indirectly by reaction with an adsorbed hydrogen. The reaction barrier is vastly more favourable when this process occurs at In or Sn sites (average: 0.26 eV), than when it occurs on Ga (average: 0.47 eV). However, there is no difference in barrier between solid and liquid surfaces. Instead, we find that Hadsis mobile only on the liquid surface, travelling due to the motion of the liquid beneath. This process drives Hadsto In/Sn sites, allowing low-barrier CO2reduction to occur only on the liquid. Therefore, the dynamic motion of liquid metal catalysts can underpin their unique reactivity. The result has far reaching implications for any protonation reaction conducted with a liquid metal catalyst.