Catalytic Conversion Of Carbon Dioxide Research Articles

Fast and sustainable CO2 conversion to propylene carbonate using fluoroalcohol-based bifunctional ionic liquids: Insights from experiments and theoretical simulations

We report on the metal-free and rapid catalytic conversion of carbon dioxide into cyclic carbonates under solventless conditions utilizing novel bifunctional fluoroalcohol-based ionic liquids (FBILs) as catalsyts. In the presence of 2.5 mol% 4-(1,1,1,3,3,3-hexafluoro-2-hydroxyisopropyl) phenyl trimethylammonium iodide (FBIL-1), under 0.1 MPa and 90 °C, excellent yield of propylene carbonate(>95%) was achieved in 1 h, which significantly shortens the reaction time, compared with the conventional catalysts. DFT calculations reveal that FBILs with fluorine-substituted hydroxyl groups exhibit stronger hydrogen bonding with epoxides compared to ILs lacking fluorine substitutions. The hydrogen bond length for ILF/PO is 1.658 Å, shorter than that for IL/PO (1.813 Å). This characteristic contributes to reducing the activation energy for the ring-opening reaction of epoxides. In the ILF/PO system, the reaction barrier is 88.72 kJ·mol−1, lower than the 101.46 kJ·mol−1 barrier for IL/PO, allowing the former to more rapidly facilitate the fixation of carbon dioxide into cyclic carbonates. Besides high catalytic efficiency, these FBILs have the characteristics of a facile synthesis route and easy post-reaction recovery.

CO2 utilization for methanol production: a review on the safety concerns and countermeasures.

The catalytic conversion of carbon dioxide is one of the important ways to achieve the goal of carbon neutralization, which can be further divided into electrocatalysis, thermal catalysis, and photocatalysis. Although photocatalysis and electrocatalysis have the advantages of mild reaction conditions and low energy consumption, the thermal catalytic conversion of CO2 has larger processing capacity, better reduction effect, and more complete industrial foundation, which is a promising technology in the future. During the development of new technology from laboratory to industrial application, ensuring the safety of production process is essential. In this work, safety optimization design of equipment, safety performance of catalysts, accident types, and their countermeasures in the industrial applications of CO2 to methanol are reviewed and discussed in depth. Based on that, future research demands for industrial process safety of CO2 to methanol were proposed, which provide guidance for the large-scale application of CO2 thermal catalytic conversion technology.

A single site catalyst supported in mesoporous UiO-66 for catalytic conversion of carbon dioxide to formate

The half-sandwich (tetrazolylpyridyl)iridium(iii) complex shows improved catalytic activity towards hydrogenation of carbon dioxide to formate when supported in a mesoporous m-UiO-66 MOF.

Review on the recent advances in catalytic conversion of carbon dioxide for synthesis of cyclic propylene carbonate

Generation of carbondioxide in the atmosphere has increased considerably over the past decades due to the increase of industrialization. This led to the increase in the global temperature which affects the eco-system. It is essential to reduce the emission of carbondioxide in the atmosphere for which different researchers are working on re-utilization of the generated carbondioxide either by converting to different products or by trapping them as carbonates. Propylene carbonate is one of the chemicals that are synthesized by using CO2 as a reactant. Propylene carbonate has many applications as an end product and acts as intermediate for synthesis of other useful chemicals. Fixation of CO2 into propylene oxide for the synthesis of propylene carbonate is still a challenging task due to the high thermodynamic stability of CO2. Propylene carbonate can be synthesized by reacting CO2 with different high energy materials using different catalyst. This review is focused on providing an idea about different types of catalyst reported for synthesis of cyclic propylene carbonate using propylene oxide and propylene glycol as the starting materials. This review also provides the mechanism for conversion of CO2 to propylene carbonate by different catalyst and at various working conditions.

Design of bifunctional 1D nanostructures for the catalytic conversion of carbon dioxide into cyclic carbonates

One dimensional silica-based nanotubes represent an innovative and promising morphology in the context of heterogeneous catalysis. Here these nanostructures were prepared for the first time as bifunctional materials, with hafnium or tin atoms inserted as single sites in the silica structure and imidazolium moieties anchored at the surface. The low dimensional solids thus present both acid sites owing to the presence of metal cations in tetrahedral coordination (co-catalyst) and nucleophilic species coming from the counterion of the imidazolium moieties (catalyst). The design of the catalysts consisted of two main steps. The Hf- or Sn-doped silica solids were initially prepared using a straightforward sol-gel method including a pH adjustment step allowing a quantitative insertion of the metal cations in the silica framework. These materials were post-functionalized with imidazolium moieties. The solids were extensively characterized thus confirming the presence of well-defined and open tubular structure, high specific surface area, successful insertion of Hf and Sn in the silica framework, and a correct functionalization with imidazolium salts. The different catalysts were tested in the valorization of CO2 with styrene oxide to give the corresponding cyclic carbonate. The bifunctional solids were stable and recyclable. The versatility of the best catalyst, represented by the Hf-based material, was confirmed using different epoxides. Finally, by tuning the reaction conditions or changing the imidazolium salt, a further boost of the catalytic performances was achieved.

Uncovering the role of yttrium in a cerium-based binary oxide in the catalytic conversion of carbon dioxide and methanol to dimethyl carbonate

Cerium(IV) oxide (CeO2)-based materials are effective catalysts for the synthesis of dimethyl carbonate (DMC) from carbon dioxide (CO2) and methanol (CH3OH). Herein, 5% Y–CeO2 was synthesized by the co-precipitation method. It forms a solid solution structure, which leads to the highest concentration of oxygen vacancies. The Y–VO–Ce active site created by Y3+ doping enhances the adsorption and activation of CO2 based on moderately passivating CH3OH adsorption. Consequently, 5% Y–CeO2 exhibited the highest CH3OH conversion rate of 0.8% and a DMC yield of 15 mmol⋅(g cat)−1, which is 1.4 times of pure CeO2 (reacting in a stainless-steel autoclave at 140 °C with a stirring speed of 1000 r⋅min−1 and an initial pressure of 3.0 MPa for 2 h). An adsorption test and in situ diffuse reflectance infrared Fourier transform spectroscopy showed that 5% Y–CeO2 could effectively inhibit the formation of triple-bonded methoxy species, and promote the formation of bidentate carbonate and bridged methoxy intermediates, which is conducive to the improvement of reaction activity.

Conversion of CO2 Hydrogenation to Methanol over K/Ni Promoted MoS2/MgO Catalyst

The chemical transformation of carbon dioxide (CO2) not only reduces the amount of carbon dioxide emitted into the Earth’s atmosphere by humans, but also produces carbon compounds that can be used as precursors for chemical and fuel production. Herein, a selective catalytic conversion of carbon dioxide to methanol is achieved by a bifunctional molybdenum disulfide catalyst (MoS2) with magnesium oxide and nickel and potassium promoters. Molybdenum disulfide prepared by the supercritical ethanol method has a large specific surface area and presents good catalytic performance with high methanol selectivity when loaded with potassium (K) and nickel (Ni) promoters. In addition, the catalysts were evaluated and it was founded that the addition of the K-promoter improved methanol selectivity. This research provides a new strategy for improved product selectivity and space–time yield (STY) of methanol in CO2 hydrogenation.

Integration of lanthanide-imidazole containing polymer with metal-organic frameworks for efficient cycloaddition of CO2 with epoxides

The heterogeneous catalytic conversion of carbon dioxide (CO2) conversion is an appealing yet highly challenging task. Introducing target-specific active sites into solid catalysts provides an alternative but promising way for boosting the chemical fixation of CO2. Here, we designed a lanthanide (III) complex with 1-vinyl imidazole (Vim) and immobilized it with DUT-5 by a combination of coordination and in situ polymerization. The resultant La-Vim/DUT-5 with high porosity and multiple active sites achieves a catalytic yield of 94% for CO2 cycloaddition of epichlorohydrin, much superior to that of each component. More importantly, such catalytic activities can be well maintained using simulated flue gas as C1 source under both dry and humid conditions. This work opens up a novel and general avenue to tailor the chemical functionality of MOFs for capturing and converting CO2 under actual conditions.

Mechanistic study on the formation of the alkyl acrylates from CO2, ethylene and alkyl iodides over nickel-based catalyst.

The catalytic conversion of carbon dioxide (CO2) and olefins into acrylates has been a long standing target, because society attempts to synthesize commodity chemicals in a more economical and sustainable fashion. In this work, two alkylation reaction pathways were investigated to explore the role of methylene linkage (-CH2-) on the formation of alkyl acrylate from coupling of CO2 and ethylene, catalyzed by a nickel catalyst in the presence of different alkyl iodides. The energy barrier of Ni-O bond cleavage decreases with increasing methylene linkage of alkyl iodides, which may be due to NPA charge transfer of alkyl iodides. Meanwhile, the O1 (ester sp3 O atom) attack route leading to the formation of alkyl acrylate competes with the O2 (carboxylic sp2 O atom) attack route in terms of energy barriers. Further studies on the fluoro-substituted alkyl acrylates show that neither CF3I nor CF3CH2I is effective in releasing trifluoroalkyl acrylates from the nickellacycle, which explains why only negligible amounts of the desired product were detected in the experiment. In addition, we investigated the non-productive pathways leading to byproducts, such as propionic acid, propionates and ion pair complexes, etc. By comparing the results obtained with CH3I, the use of C2H5I as an electrophilic reagent may stabilize the non-productive intermediates. The methylene linkage has little effect on the main productive pathway. However, it has a significant influence on the side reactions, which is detrimental to the formation of alkyl acrylate in competing with the main productive pathway.

Two novel metal-organic frameworks functionalised with pentamethylcyclopentadienyl iridium(III) chloride for catalytic conversion of carbon dioxide to formate.

Hydrogenation of CO2 to formate is a vital reaction, because formate is an excellent hydrogen carrier, which yields blue hydrogen. Blue hydrogen is comparatively cheaper and attractive as the world envisions the hydrogen economy. In this work, two isostructural lanthanide-based MOFs (JMS-6 and JMS-7 [Ln(bpdc)3/2(dmf)2(H2O)2]n) were prepared and used as support materials for molecular catalysts. The bipyridyl MOF backbone were functionalised using pentamethylcyclopentadienyl iridium(III) chloride to give Ir(III)@JMS-6a and Ir(III)@JMS-7a. XPS of the functionalised MOFs show downfield shifts in the N 1s binding energy indicating successful grafting of the complex to the MOF. Hydrogenation experiments in the presence of an organic base showed that the functionalised MOFs were active towards converting CO2 to formate. Ir(III)@JMS-6a and Ir(III)@JMS-7a exhibited the highest turnover numbers of 813 and 621 respectively. ICP-OES indicated insignificant leaching during catalysis. TEM images and XPS data of the recovered catalyst ruled out the presence of Ir(0), confirming that the activity observed was attributed to the molecular Iridium(III) centres.

Effective tri-metallic TiO2 supported catalyst for hydrocarbon production from carbon dioxide

The current socio-economic issues with concerns on environmental quality and global warming are attributed to high concentrations of atmospheric carbon dioxide due to extensive usage of fossil fuels. Thus, over the last two decades, comprehensive work has been reported on carbon capture and storage and catalytic conversion of carbon dioxide to hydrocarbons. Among these, the reactions with hydrocarbons to form value-added products have been in focus. In this work, an attempt was made to identify the feasibility of the reaction: carbon dioxide and steam to form hydrocarbons of fuel value. After reviewing the literature on the development of various catalysts and their mechanism, a multi-metallic catalyst supported by TiO2 Nano-needles was explored. The reaction mechanism is expected to proceed with activated CO2 complex and hydroxyl groups over the metal oxide catalyst. Current reported work on CO2 and Hydrogen proceeds with activated CO2 and protons over the catalyst. The characterization techniques mainly XPS, XRD, TGA, FESEM-EDAX, FTIR, and NMR were used to analyze the catalyst activity and to confirm the products formed. The reaction is found to yield methanol and oxygen only. However, the conversion is found to be 0.4% - 3.8% in the temperature range 350°C to 550°C. The reaction of CO2 with hydroxyl groups from water vapor can be effective as an alternative to the reaction with protons from hydrogen.

Research status, challenges and future prospects of renewable synthetic fuel catalysts for CO2 photocatalytic reduction conversion.

In recent years, with global climate change, the utilization of carbon dioxide as a resource has become an important goal of human society to achieve carbon peaking and carbon neutrality. Among them, the catalytic conversion of carbon dioxide to generate renewable fuels has received great attention. As one of these methods, photocatalysis has its unique properties and mechanism, which can only rely on sunlight without inputting other energy. It is an emerging discipline with great development prospects. The core of photocatalysis lies in the development of photocatalysts with high activity, high selectivity, low cost, and high durability. This review first introduces the background and mechanism of photocatalysis, then introduces various types of photocatalysts based on different substrates, and analyzes the methods and mechanisms to improve the activity and selectivity of photocatalysts. Finally, combining the plasmon effect with photocatalysis, the review analyzes the promoting effect of the plasmon effect on the photocatalytic carbon dioxide synthesis of renewable fuels, which provides a new idea for it.

Structure Sensitivity of CO2 Conversion over Nickel Metal Nanoparticles Explained by Micro-Kinetics Simulations.

Nickel metal nanoparticles are intensively researched for the catalytic conversion of carbon dioxide. They are commercially explored in the so-called power-to-methane application in which renewably resourced H2 reacts with CO2 to produce CH4, which is better known as the Sabatier reaction. Previous work has shown that this reaction is structure-sensitive. For instance, Ni/SiO2 catalysts reveal a maximum performance when nickel metal nanoparticles of ∼2-3 nm are used. Particularly important to a better understanding of the structure sensitivity of the Sabatier reaction over nickel-based catalysts is to understand all relevant elementary reaction steps over various nickel metal facets because this will tell as to which type of nickel facets and which elementary reaction steps are crucial for designing an efficient nickel-based methanation catalyst. In this work, we have determined by density functional theory (DFT) calculations and micro-kinetics modeling (MKM) simulations that the two terrace facets Ni(111) and Ni(100) and the stepped facet Ni(211) barely show any activity in CO2 methanation. The stepped facet Ni(110) turned out to be the most effective in CO2 methanation. Herein, it was found that the dominant kinetic route corresponds to a combination of the carbide and formate reaction pathways. It was found that the dissociation of H2CO* toward CH2* and O* is the most critical elementary reaction step on this Ni(110) facet. The calculated activity of a range of Wulff-constructed nickel metal nanoparticles, accounting for varying ratios of the different facets and undercoordinated atoms exposed, reveals the same trend of activity-versus-nanoparticle size, as was observed in previous experimental work from our research group, thereby providing an explanation for the structure-sensitive nature of the Sabatier reaction.

Sandwich-structured nickel/kaolinite catalyst with boosted stability for dry reforming of methane with carbon dioxide

Dry reforming of methane (DRM), catalytic conversion of carbon dioxide and methane into syngas, is an appealing process that converts two greenhouse gases into a versatile chemical feedstock. Design of efficient catalysts with high activity and stability is the key to perform the reaction. Unfortunately, the high reaction temperature of DRM often causes sintering and aggregation of the active metal particles in the catalysts (particularly Ni-based catalysts) and the consequent formation of deposited carbon results in rapid deactivation of the catalysts. One way to address this issue is to design confined catalysts. In this study, an “intercalation-etching” strategy to delaminate raw kaolinite into pitting-rich nanosheets was developed and a sandwich-structured Ni/kaolinite catalyst was fabricated by assembling Ni nanoparticles with the nanosheets. In contrast with Ni catalysts supported on raw kaolinite or acid-activated kaolinite, the sandwich-structured Ni/kaolinite catalyst remained highly steady with time on stream because of its confinement and isolation effect. Furthermore, the carbon deposits generated in the sandwich-structured catalyst were filamentous carbon, which was beneficial to the catalytic activity and stability. On the contrary, the carbon deposits generated in the reference catalysts were coated carbon, which caused the deactivation of the catalysts.

Challenges and Prospects in the Catalytic Conversion of Carbon Dioxide to Formaldehyde

AbstractFormaldehyde (HCHO) is a crucial C1 building block for daily‐life commodities in a wide range of industrial processes. Industrial production of HCHO today is based on energy‐ and cost‐intensive gas‐phase catalytic oxidation of methanol, which calls for exploring other and more sustainable ways of carrying out this process. Utilization of carbon dioxide (CO2) as precursor presents a promising strategy to simultaneously mitigate the carbon footprint and alleviate environmental issues. This Minireview summarizes recent progress in CO2‐to‐HCHO conversion using hydrogenation, hydroboration/hydrosilylation as well as photochemical, electrochemical, photoelectrochemical, and enzymatic approaches. The active species, reaction intermediates, and mechanistic pathways are discussed to deepen the understanding of HCHO selectivity issues. Finally, shortcomings and prospects of the various strategies for sustainable reduction of CO2 to HCHO are discussed.

Challenges and Prospects in the Catalytic Conversion of Carbon Dioxide to Formaldehyde.

Formaldehyde (HCHO) is a crucial C1 building block for daily-life commodities in a wide range of industrial processes. Industrial production of HCHO today is based on energy- and cost-intensive gas-phase catalytic oxidation of methanol, which calls for exploring other and more sustainable ways of carrying out this process. Utilization of carbon dioxide (CO2 ) as precursor presents a promising strategy to simultaneously mitigate the carbon footprint and alleviate environmental issues. This Minireview summarizes recent progress in CO2 -to-HCHO conversion using hydrogenation, hydroboration/hydrosilylation as well as photochemical, electrochemical, photoelectrochemical, and enzymatic approaches. The active species, reaction intermediates, and mechanistic pathways are discussed to deepen the understanding of HCHO selectivity issues. Finally, shortcomings and prospects of the various strategies for sustainable reduction of CO2 to HCHO are discussed.

The Divergent Reactivity of Lactones Derived from Butadiene and Carbon Dioxide in Macromolecular Synthesis.

The catalytic conversion of carbon dioxide and 1,3-butadiene into unsaturated lactone monomers provides an efficient route for converting sustainable carbon feedstocks into novel macromolecules. The chemical reactivity of this monomer is reviewed in order to highlight the many viable mechanistic pathways. Polymerization strategies, monomer alterations, and post-polymerization modifications are covered. The polymerization methods include radical, coordination, conjugate addition, ring-opening, olefin metathesis, and thiol-ene chemistries. Materials derived from these processes possess a wide range of function including responsiveness, degradability, adhesion, recyclability, and self-assembly. These aspects along with the advances in polymer chemistry that make them possible are discussed, along with a perspective on the future directions of the field.

Hydrogen reactivity factor and effects of oxygen on methane conversion rate by chemical equilibrium calculation

To solve the global warming problem, it is necessary to minimize the use of fossil fuels such as coal and natural gas. As a power-to-gas technology, CO2 methanation has been focused on, which can produce the synthetic methane through the catalytic conversion of carbon dioxide and hydrogen, called methanation. However, it is better not to use catalysts, because the catalyst could be damaged due to the thermal degradation due to the exothermic reaction. In the present study, we have investigated the characteristics of the methanation reaction based on the chemical equilibrium calculations, NASA-CEA. We changed the reaction temperature, the ambient pressure and the ratio of carbon dioxide and hydrogen. Six various pressures of 1, 2, 5, 10, 15, 20 atm were applied, with the temperature range of 500 to 1500 K. The methane conversion rate is defined by the deficient reactant of carbon dioxide or hydrogen. Especially, a new parameter of the hydrogen reactivity factor (H.R.F.) is proposed to characterize the initial components in the mixture with the methane conversion rate. To promote the methanation reaction, we have tested to add oxygen as the secondary oxidizer. Results show that, in the case of no oxygen, the methane conversion rate is almost 100% for the excess of hydrogen (H.R.F. < 1). As more carbon dioxide is supplied at (H.R.F. > 1), the methane conversion rate is decreased. The methane conversion rate is reduced at higher reaction temperature or lower ambient pressure, which can be explained by the so-called Le Chatelier's principle. However, the methane conversion rate is enlarged by adding oxygen. This is the case when carbon dioxide is the excess species, and coking is observed with production of graphite through the pyrolysis of methane. Since the mass fraction of graphite is smaller when oxygen is added, oxygen can improve the methane conversion rate due to less coking. For developing the non-catalytic system, the methanation reactor with circulation (MeRCi) has been proposed, where the reactants in the flow are circulated to ensure the enough residence time and utilize the exothermic heat of the methanation reaction.

Advanced Materials and Technologies toward Carbon Neutrality

ConspectusGlobal climate change caused by the excessive emission of greenhouse gases has become one of the greatest threats to human survival in the 21st century. Carbon dioxide is the main greenhouse gas on earth and has brought about serious environmental problems nowadays. On the basis of the current situation, it is urgent to reach the peak of carbon dioxide emission and then achieve carbon neutrality via policy support and engineering strategies within advanced materials and technologies. Carbon neutrality requires an appropriate balance between the emission and reduction of carbon dioxide. The emission of carbon dioxide mainly comes from modern industries, and the reduction requires several steps, including capture, conversion, and application. On one hand, it can reduce carbon dioxide emission by promoting the transformation of industrial structure. On the other hand, it is necessary to remove high-level carbon dioxide existing in the atmosphere by physical and chemical methods such as adsorption capture and catalytic conversion.This Account showcases our recent progress on carbon neutrality for the reduction of carbon dioxide through capture and conversion methods within advanced materials and technologies. We mainly focus on the right side of the carbon scale and have made some advances such as moisture-swing chemisorption for carbon dioxide capture, the reduction of oxygen-containing carbon dioxide, and the photothermal catalytic conversion of carbon dioxide. Different from previous studies, our work is about developing materials and techniques for practical applications. First, we have made attempts to develop cheap sorbents with high stability and a high adsorption capacity. Second, we have reported a moisture-swing technique with the capability of directly capturing carbon dioxide from the atmosphere by relying on the humidity variation with low energy consumption. This technique is promising for realizing real-time carbon dioxide capture and utilization, which avoids high-cost storage and transport processes. Third, our work on carbon dioxide utilization focuses on efficient conversion under practical conditions. For instance, we have developed perovskite catalysts for converting carbon dioxide to carbon monoxide in an oxygen-containing environment. Furthermore, core–shell catalysts have been reported for carbon dioxide conversion with a high selectivity of 83% driven by solar energy. In addition, practical applications of captured carbon dioxide have been explored with respect to carbon dioxide-assisted graphene exfoliation, keeping fruit fresh, and crop growth promotion with carbon dioxide gas fertilizer. A future perspective on the challenges and opportunities for carbon neutrality has been provided on the basis of our experimental studies and theoretical predictions. It is expected that this Account will promote tremendous effort in the development of advanced materials and engineering technologies toward the realization of carbon neutrality by the middle of this century.

Current status of research on the synthesis of hydrogen, hydrocarbons and conversion of carbon dioxide in the framework of reducing anthropogenic pressure on the environment and switching to environmentally friendly energy sources

The world’s energy sector faces two major challenges: one is the rapid rise in the price of oil products, and the other is the increase in the amount of carbon dioxide emitted by industry into the atmosphere, leading to global warming. Developments in alternative energy sources, such as solar and hydrogen energy, are becoming increasingly relevant. In this regard, there has been a lot of interest in converting CO2 into useful products. Hydrogenation of carbon dioxide into useful energy resources and chemicals is becoming increasingly important as it is seen as a promising way to reclaim harmful CO2 as a by-product. The article considers modern technologies of hydrogen production and industrial conversion of carbon dioxide into useful products, and also describes the author’s natural method of catalytic conversion of carbon dioxide into useful green energy resources – hydrogen and hydrocarbons.