145533-44-4Relevant academic research and scientific papers
Hydrotalcite anchored ruthenium catalyst for CO2 hydrogenation reaction
Srivastava, Vivek
, p. 853 - 863 (2018)
We developed a series of new organic-inorganic hybrid hydrotalcite functionalized Ru catalytic systems. All the developed materials have been studied by FTIR, N2 physisorption, ICP-OES, XPS, NMR (1H, 13C, 29Si) and TEM analysis were performed to know the physiochemical behavior and structural morphology of functionalized hydrotalcite materials. XPS results strongly suggest that it involves the formation of N-Ru coordination bonds. We applied these well analyzed materials for CO2 hydrogenation reaction as catalyst (with and without ionic liquid medium). We found that Ru metal containing functionalized hydrotalcite materials were highly active and stable (in terms of catalyst leaching and recycling). The heterogeneous catalyst can be easily recovered and reused 8 times without significant loss of catalytic activity and selectivity, which is a better green alternative for practical applications.
Heterogeneous Silica Tethered Ruthenium Catalysts for Carbon Sequestration Reaction
Upadhyay, Praveenkumar Ramprakash,Srivastava, Vivek
, p. 1478 - 1486 (2016)
Abstract: A series of silica-tethered Ru complexes were easily prepared and further analyzed by sophisticated analytical techniques such as FTIR, N2 physisorption, ICP-OES and XPS analysis. After proper characterization of catalyst structure, we exploited them to synthesize formic acid followed by CO2 hydrogenation reaction. To determine the exact amount of reaction product (formic acid) in the reaction mixture we performed the 1H NMR analysis, using dioxane as an internal slandered. No degradation of dioxane as well as the side product formation was recorded in this study. Reported catalytic systems were found active and stable in terms of formic acid formation and catalyst recycling experiment up to nine consecutive runs. Graphical Abstract: [Figure not available: see fulltext.]
Silica Tethered Ruthenium Catalyst for the Hydrogenation of CO2 Gas
Upadhyay, Praveenkumar R.,Srivastava, Vivek
, p. 380 - 387 (2016)
Background: In recent years CO2 utilization and conversion of CO2 into the value added chemicals have attracted great attention of leading research groups. However, CO2 is widely accepted as reagent for the synthesis of carbonates and other important chemicals such as methanol, aspirin, formic acid etc, but CO2 reduction is still a major challenge for the scientific community as they are extremely thermodynamically stable. In this report, we are offering the synthesis of silica-tethered ruthenium catalyst (SRUC) for the hydrogenation of CO2 to formic acid. pageu65533? Methods: The SIRUC catalytic system was synthesized by a multistep grafting process using iminophophine ligand tethered to mesoporus SBA-15 inorganic support. After activating the SRUC catalyst with hydrogen gas, it was applied as hydrogenating catalyst for CO2 gas. It is worth noted that, SBA-15 was synthesized as per reported protocol and the important IV- type isotherm was recorded while performing N2 physisorption analysis.pageu65533? Results: The catalytic efficiency of silica-tethered Ru catalysts was screened for the hydrogenation of CO2 to formic acid. The hydrogenation reaction was carried out in 100 mL autoclave with triethyl amine (NEt3 ) and water under the pressure of CO2 and hydrogen gas (40 bar, CO2 : H2 =1:1) at 75° C. The formation of formic acid (or formate) was calculated through 1H NMR. As per the experimental data, it was clearly observed that catalyst system only works effectively with phosphine ligands and offered the formic acid with significant TON/TOF value opposite to SRUC-4A catalytic system. Higher catalytic activity in terms of TON/TOF value was obtained with SRUC-1A material carries the bidentate phosphine ligand at 100° C.? Conclusion: In this manuscript, we reported a new protocol to synthesize mesoporous silica-tethered Ru complexes (SRUC 1A-4A). Among these, materials, SRUC 1A was found and effective heterogeneous catalyst for the selective CO2 hydrogenation reaction to obtain formic acid under normal reaction condition. In terms of catalyst recycling, this catalytic system was found highly active in catalyst recycling test up to 6 cycles without any significant loss of TON value of formic acid. In parallel, we also performed the filtration experiment and the obtained results were found in good agreement with recycling test results.
Rhodium Iminophosphine Complexes as Efficacious Oxygen Carriers. Crystal Structure of a Representative Dioxygen Adduct
Ghilardi, Carlo A.,Midollini, Stefano,Moneti, Simonetta,Orlandini, Annabella,Scapacci, Giancarlo
, p. 3371 - 3376 (2007/10/02)
The synthesis, characterization and reactivity of some square-planar rhodium(I) complexes with new bidentate ligands o-Ph2PC6H4CH=NR (R = Et, Prn, Pri or But) having NP donor atoms have been investigated.Depending on the steric crowding of the ligands the complexes can reversibly form dioxygen adducts, in organic solvent solutions at room temperature.The oxygenation-deoxygenation cycles, which have been monitored by 31P NMR spectroscopy, can be repeated several times with minor loss in the starting material.A reversible adduct is similarly obtained by reaction with CO.The reaction of the dioxygen adduct with SO2 allows the formation of a sulfate derivative.The molecular structure of the dioxygen complex i)2(O2)>BPh4 has been determined by a single-crystal diffraction study: triclinic, space group P, a = 17.450(7), b = 16.518(7), c = 9.624(5) Angstroem, α = 92.79(6), β = 92.52(7), γ = 92.69(7) deg, Z = 2, R = 0.057.The co-ordination of the metal may be alternatively described as distorted trigonal bipyrimidal or distorted octahedral, according to whether the dioxygen molecule is treated as occupying one or two equatorial sites respectively.The two oxgen atoms, which are equidistant from the metal, are 1.436(9) Angstroem apart.
