From carbon dioxide to methane: homogeneous reduction of carbon dioxide with hydrosilanes catalyzed by zirconium-borane complexes

A mixture of a zirconium benzyl phenoxide complex and tris(pentafluorophenyl)borane is reported that catalyzes the hydrosilation reaction of carbon dioxide to generate methane via a bis(silyl)acetal intermediate.     

Electrochemical conversion of carbon dioxide catalysed by benzil

It has been shown it is possible to reduce carbon dioxide electrochemically using benzil as a homogeneous electron transfer agent. It was found that oxalic acid is the basic product formed during the electrochemical reduction of carbon dioxide. __________ Translated from Teoreticheskaya i éksperimental’naya Khimiya, Vol. 42, No. 1, pp. 29–32, January–February, 2006.     

Application of photo catalysis for mitigation of carbon dioxide

Photo catalytic reduction of carbon dioxide by water or artificial photosynthesis to yield hydrocarbons (methane and methanol, etc., termed “solar fuels”) is being studied extensively, with the twin objectives of developing an effective means of limiting atmospheric CO₂ levels and evolving a sustainable alternative route for production of fuels and chemicals. This short review covers the origin and thermodynamic and kinetic features of the process, the basic photocatalytic principles involved, the rationale behind the choice of different catalysts and their performance, the effect of process conditions, the effect of the structural and photophysical properties of the different catalysts on their performance, mechanistic pathways, surface transformations, challenges involved in the practical application of the process, and future directions for research.     

Plasma activated catalysis for carbon dioxide dissociation: A review

In this paper, we have discussed the perspectives on plasma activated catalysis specifically for carbon dioxide dissociation. An insight has been provided on various types of plasma set-ups used for carbon dioxide dissociation, along with the role of plasma chemistry and reactor design considerations in such chemical processes. Effectiveness of various types of plasma for carbon dioxide dissociation have been reviewed in detail.     

Advances in photothermal conversion of carbon dioxide to solar fuels

Converting carbon dioxide(CO₂) into useful fuels or chemical feedstocks is important for achieving peak carbon emission and carbon neutrality.Recently,photothermal catalysis has been extensively studied and applied due to its advantages over traditional heat-driven catalysis.In this review,we focus on photothermal catalysis of thermodynamically uphill reactions that convert CO₂ into value-added products.We first introduce the fundamentals of photothermal catalysis for CO     

Molecular simulation of the homogeneous crystal nucleation of carbon dioxide

We report on a molecular simulation study of the homogeneous nucleation of CO2 in the supercooled liquid at low pressure (P = 5 MPa) and for degrees of supercooling ranging from 32% to 60%. In all cases, regardless of the degree of supercooling, the structure of the crystal nuclei is that of the Pa3 phase, the thermodynamically stable phase. For the more moderate degree of supercooling of 32%, the nucleation is an activated process and requires a method to sample states of high free energy. In this work, we apply a series of bias potentials, which promote the ordering of the centers of mass of the molecules and allow us to gradually grow crystal nuclei. The reliability of the results so obtained is assessed by studying the evolution of the nuclei in the absence of any bias potential, and by determining their probability of growth. We estimate that the size of the critical nucleus, for which the probability of growth is 0.5, is approximately 240 molecules. Throughout the nucleation process, the crystal nuclei clearly exhibit a Pa3 structure, in apparent contradiction with Ostwald's rule of stages. The other polymorphs have a much larger free energy. This makes their formation highly unlikely and accounts for the fact that the nucleation of CO2 proceeds directly in the stable Pa3 structure.     

In situ formation of ruthenium catalysts for the homogeneous hydrogenation of carbon dioxide

A total of 44 different phosphines were tested, in combination with [RuCl(2)(C(6)H(6))](2) and three other Ru(II) precursors, for their ability to form active catalysts for the hydrogenation of CO(2) to formic acid. Half (22) of the ligands formed catalysts of significant activity, and only 6 resulted in very high rates of production of formic acid. These were PMe(3), PPhMe(2), dppm, dppe, and cis- and trans-Ph(2)PCH=CHPPh(2). The in situ catalysts prepared from [RuCl(2)(C(6)H(6))](2) and any of these 6 phosphine ligands were found to be at least as efficient as the isolated catalyst RuCl(O(2)CMe)(PMe(3))(4). There was no correlation between the basicity of monophosphines (PR(3)) and the activity of the catalysts formed from them. However, weakly basic diphosphines formed highly active catalysts only if their bite angles were small, while more strongly basic diphosphines had the opposite trend. In situ (31)P NMR spectroscopy showed that trans-Ru(H)(2)(dppm)(2), trans-RuCl(2)(dppm)(2), trans-RuHCl(dppm)(2), cis-Ru(H)(O(2)CH)(dppm)(2), and cis-Ru(O(2)CH)(2)(dppm)(2) are produced as the major metal-containing species in reactions of dppm with [RuCl(2)(C(6)H(6))](2) under catalytic conditions at 50 degrees C.     

A versatile metal-organic framework for carbon dioxide capture and cooperative catalysis

A multi-functional MOF was constructed from Cu paddlewheel motifs and a judiciously designed novel ligand bearing carboxylate, pyridine, and amide groups. exhibits selective adsorption of CO(2) over CH(4) and excellent catalytic activity in a tandem one-pot deacetalization-Knoevenagel condensation reaction as a cooperative catalyst.     

Cascade catalysis for the homogeneous hydrogenation of CO2 to methanol

This communication demonstrates the homogeneous hydrogenation of CO(2) to CH(3)OH via cascade catalysis. Three different homogeneous catalysts, (PMe(3))(4)Ru(Cl)(OAc), Sc(OTf)(3), and (PNN)Ru(CO)(H), operate in sequence to promote this transformation.     

Bifunctional coordination polymers as efficient catalysts for carbon dioxide conversion

The multidentate ligand H₂ L upon complexation with Zn (II) and Cd (II) provide a one‐dimensional polymeric networks. These coordination polymers (CPs) CP‐1 and CP‐2 containing Zn (II) and Cd (II) metals respectively are well characterized. The single crystal structural analysis confirms the formation of one‐dimensional coordination polymer with zigzag fashion in CP‐1 and ladder chain CP‐2 . Both the CPs are applied as catalysts to synthesize various cyclic carbonates from epoxides and carbon dioxide. The catalysts are giving better conversion under solvent‐free and additive‐free condition using 10 bar CO₂ and 100 °C as optimized pressure and temperature. The detailed kinetic experiments suggesting the first order kinetics, the energy of activation (Ea) is calculated for this catalytic conversion.     

Metallodendritic materials for heterogenized homogeneous catalysis

Design of supports containing a hyperbranched backbone and active transition metal centers at the periphery is described. Such nanoarchitectures can be easily assembled from 3,5-dihydroxybenzyl alcohol and dimethylsilylamine using a divergent synthetic methodology. Following a controlled reaction pathway, construction of dendrimers of up to generation 5 is achieved, while a simple mix of reagents in one-pot or with sequential additions yields analogous hyperbranched polymers. Subsequent functionalization at the periphery with phosphine followed by Rh(I) centers yields the desired metallodendritic materials. The efficiency of the latter in catalytic hydrogenation of decene under varied conditions is surveyed.     

Methane conversion with carbon dioxide on nickel aluminides

The catalytic activity of several samples based on nickel aluminides in methane conversion with carbon dioxide was studied. Nickel aluminides were prepared by the method of self-propagating high-temperature synthesis. The Ni₃Al system containing the nickel metal phase exhibited high activity at temperatures above 1073 K. The systems based on Ni₂Al₃ and NiAl only containing intermetallic compound phases were inactive.     

Permeation of carbon dioxide through homogeneous and asymmetric polysulfone membranes

To confirm the validity of the working assumption that a thin dense skin layer in an asymmetric membrane can be essentially replaced by a thick homogeneous dense membrane, both homogeneous and asymmetric polysulfone membranes were prepared by solvent casting, and the permeation behavior of carbon dioxide through these two types of membranes was investigated. The pressure dependence of the mean permeability coefficient through an asymmetric polysulfone membrane is apparently very similar to that through a homogeneous dense membrane, following the dual mode mobility model driven by gradients of chemical potential. The dense skin layer in the asymmetric membrane can be simulated approximately by a homogeneous dense membrane from the point of view of gas sorption and diffusion.     

A perspective on the electrocatalytic conversion of carbon dioxide to methanol with metallomacrocyclic catalysts

Electrocatalytic carb on dioxide reducti on(CO₂R)presents a promising route to establish zero-e mission carb on cycle and store in termittent ren ewable energy into chemical fuels for steady energy supply.Methanol is an ideal energy carrier as alternative fuels and one of the most important commodity chemicals.Nevertheless,methanol is currently mainly produced from fossil-based syngas,the production of which yields tremendous carb on emission globally.Direct CO₂R towards metha nol poses great potential to shift the paradigm of methanol production.In this perspective,we focus our discussions on producing methanol from electrochemical CO₂R,using metallomacrocyclic molecules as the model catalysts.We discuss the motivation of having methanol as the sole CO₂R product,the documented application of metallomacrocyclic catalysts for CO₂R,and recent advance in catalyzing CO₂ to methanol with cobalt phthalocyanine-based catalysts.We attempt to understand the key factors in determining the activity,selectivity,and stability of electrocatalytic CO₂-to-methanol conversion,and to draw mechanistic insights from existing observations.Finally,we identify the challenges hindering methanol electrosynthesis directly from CO₂ and some intriguing directions worthy of further investigation and exploration.     

无金属参与的CO_2催化转化的研究进展

CO2既是导致全球变暖的主要温室气体,又是来源丰富廉价易得的可再生C1资源,因此CO2的资源化利用是绿色化学的重要研究方向之一.本文作者分别从无金属参与的CO2催化转化制备五元环状碳酸酯、噁唑啉酮以及CO2还原等几个方面对其催化转化进行综述,并对CO2有机催化转化进行了展望.