Adsorption Of Acrolein Research Articles

Studies on transition metals (Rh, Ir, Co) doped silicon carbide nanotubes (SiCNT) for the detection and adsorption of acrolein: Insight from DFT approach

The remarkable ability for gas sensors to detect pollutants makes the development of sensors an interesting one. Employing the density functional theory at the DFT/ωB97XD/def2-SVP (d,p) level of computation, the potential for SiC (Nanotube) and Rh, Ir and Co doped models to effectively adsorbed acrolein is investigated. The electronic properties of the nanotubes show, the significance of doping as observed energy gap of doped surfaces was considerably reduced compared to the native SiCNT, while the sensitivity, and adsorption properties of the Rh, Ir, and Co doped systems are enhanced and confirms suitability for the adsorption of acrolein. Similarly, the doped systems showed strong intermolecular interaction owing to high values for perturbation energies with major contributions from the donor lone pair (LP) orbital – antibonding (π*) acceptor orbital. Also, the density of state (DOS) plot revealed the presence of antibonding MOs in the studied systems. From the topology analysis, the non-covalent nature of the interaction between the adsorbate and adsorbent is dominant for all systems which implies excellent adsorptive behavior. Furthermore, our estimates for adsorption energies reveal that SiCNT adsorbs acrolein more strongly than doped systems, with an Eads of −4.54 eV, while Ir@SiCNT exhibits less adsorption than other systems, with an Eads of −4.10 eV, markedly suggesting it as a potential acrolein sensing material, profoundly supported by the enthalpy change and free Gibbs energy thermodynamic properties results in conjunction Furthermore, our estimates for adsorption energies reveal that SiCNT adsorbs acrolein more strongly than doped systems, with an Eads of −4.54 eV, while Ir@SiCNT exhibits less adsorption than other systems, with an Eads of −4.10 eV, markedly suggesting it as a potential acrolein sensing material, profoundly supported by the enthalpy change and free Gibbs energy thermodynamic properties results in conjunction with the systems’ electrical conductivity (σ), charge transfer (Qt), Fermi level (EFL), recovery time, and sensor response mechanism of detection. SiCNT_AC from the ab initio molecular dyanamic simulation showed a stable configuration with an initial total energy of 794.730 and a decrease final energy of 794.048 which gave rise to an average and standard deviation of 793.748 ± 0.357 compared to other studied systems. Our findings demonstrate the efficacy of the studied metallic SiCNT materials to effectively adsorb acrolein gas molecules, which provides for sensitivity, repeatability, reproducibility of acrolein sensing experimental work.

DFT investigation for the adsorption of acrolein onto the surface of pristine and doped C70: NBO and QTAIM analyses

Density functional theory was used in the present study to compare the sensitivity and reactivity of pristine and doped fullerene C70 variants (including Al and Si) to the acrolein (AC) molecule. It was determined that the O-head of AC is responsible for its physisorption onto the C70. The adsorption's energy was close to −3.11 kcal/mol. During adsorption, the associated cluster's electrical conductivity remained nearly unaltered. Al and Si atoms that replace C atoms in fullerene increase their activity. Si had an estimated adsorption energy of −28.23 kcal/mol, whereas Al was expected to have a value of −48.95 kcal/mol. The LUMO-HOMO energy gap appears to impact the AC molecule significantly. The stability of LUMOs in Si-doped fullerene was dramatically reduced by AC adsorption, whereas its electrical conductivity was increased. Simultaneously, electrical signals linked to the existence of AC in the environment were created. The outcomes demonstrated the high reliability of Si-doped fullerene as a AC electronic sensor. Al-doped fullerene is an Ф-type candidate to be utilized as a AC sensor due to the significant effects of the AC on its Fermi level and functions. The stable site of the AC/Al-fullerene complex showed a maximum peak at 784 nm, following the results of the time-dependent density functional theory (TD-DFT).

Adsorption, thermal conversion, and catalytic hydrogenation of acrolein on Cu surfaces

The adsorption, thermal chemistry, and catalytic hydrogenation of acrolein on copper model surfaces was characterized by a combination of surface-science techniques, namely, reflection–absorption infrared spectroscopy (RAIRS) and temperature program desorption (TPD), quantum mechanics (DFT) calculations, and catalytic kinetic measurements using a so-called “high-pressure cell”. Adsorption of acrolein on the Cu surface was found to involve both the carbonyl oxygen atom and the CC bond. Thermal activation leads to early dissociation and dehydrogenation to produce acetylene and carbon monoxide below 160 K, and later to the production of ketene (220 K) and propene (260 K). Under vacuum hydrogenation with H2 is not possible, but upon predosing of the surface with atomic H all the possible hydrogenation products, namely, propanal, 1-propanol, and allyl alcohol, were detected in TPD experiments, at 162, 190, and 210 K, respectively. Finally, catalytic hydrogenation under atmospheric pressures is slow and only produces propanal, at turnover frequencies below 0.2 s−1.

Adsorption of acrolein and its hydrogenation products on Cu(111).

The adsorption of acrolein and its hydrogenation products propanal, 1-propanol, and 2-propenol on Cu(111) was studied by reflection absorption infrared spectroscopy (RAIRS) and temperature-programmed desorption (TPD). The experimental RAIR spectra were obtained by adsorbing multilayers of each molecule at 85 K and then annealing the surface up to 200 K to desorb the multilayer and produce the most stable monolayer structure on the surface. Each of the four molecules adsorbs weakly to the surface and desorbs at temperatures below 225 K. Compared to acrolein and propanal, the two alcohols, 2-propenol and 1-propanol, have notably higher desorption temperatures and broadened and redshifted O-H stretches that reveal strong hydrogen bonding in the multilayers. Upon annealing to 160 K, the OH stretches of both 2-propenol and 1-propanol disappear, indicating the hydrogen bonding in the multilayers is not present in the monolayers. For 2-propenol, the hydrogen bonding in the multilayer correlates with the observation of the CC stretch at 1647 cm-1, which is invisible for the monolayer. This suggests that the CC bond is parallel to the surface for monolayer coverages of 2-propenol. Similarly, for propanal, the CO stretch peak at 1735 cm-1 compared to those at 1671 and 1695 cm-1 is very weak at low coverages but becomes the most prominent peak for the multilayer, indicating a change in molecular orientation. For acrolein, the out-of-plane bending modes are more intense than the CO stretch at submonolayer coverages, indicating that the molecular plane is mainly parallel to the surface. In contrast, the opposite intensity trend was observed for multilayer acrolein, suggesting that the CO bonds are tilted away from the surface.

Structural, electronic, and energetic investigations of acrolein adsorption on B36 borophene nanosheet: a dispersion-corrected DFT insight.

The adsorption of acrolein (AC) onto the surface of B36 borophene nanosheet was studied using dispersion-corrected density functional theory (DFT). The structural and electronic properties were scrutinized by several quantum chemical parameters such as HOMO-LUMO gap, condensed Fukui function, molecular electrostatic potential (ESP), and the density of states (DOS). The non-covalent interactions (NCI) were explored by combined reduced density gradient (RDG-NCI) and energy decomposition analysis (EDA) techniques. It was found that the adsorption of acrolein on both convex and concave surfaces of borophene is mainly governed by van der Waals interactions. Our calculations showed that the adsorption energy is strengthened and favored when multiple acrolein molecules adsorb on the edge sides of borophene through their terminal carbonyl oxygen atom. Furthermore, the calculated HOMO-LUMO energy gaps were significantly reduced upon adsorption affecting, therefore, the electrical conductance of borophene. These results should be useful in designing acrolein sensors.

Theoretical Insights into Vinyl Derivatives Adsorption on a Cu(100) Surface

Here, we present a thorough theoretical study of the adsorption of acrolein (ACO), acrylonitrile (ACN), and acrylamide (ACA) on Cu(100) surface. For this purpose, we have used the density functional theory, imposing periodic boundary conditions to have a correct description of the electronic band structure of the metal and including dispersion forces through two different schemes: the D2 method of Grimme and the vdW-DF. We have found several adsorption geometries. In all of them, the vinyl group together with the amide (in ACA), ciano (in ACN), and carbonyl (in ACO) groups, is highly involved. The highest adsorption energy is found for acrylamide, followed by acrolein and the lowest for acrylonitrile (depending on the level of theory employed ∼1.2, 1.0, and 0.9 eV, respectively). We show that a strong coupling between the π electronic system (both occupied and virtual orbitals) and the electronic levels of the metal is mainly responsible of the chemisorption. As a consequence, electronic density is transferred from the surface to the molecule, whose carbon atoms acquire a partial sp3 hybridization. Lone-pair orbitals of the cyano, amide, and carbonyl groups also play a role in the interaction. The simulations and following analysis allow to disentangle the nature of the interaction, which can be explained on the basis of a simple chemical picture: donation from the occupied lone pair and π orbitals of the molecule to the surface and backdonation from the surface to the π* orbital of the molecule (π-backbonding).

Nanofilter platform based on functionalized carbon nanotubes for adsorption and elimination of Acrolein, a toxicant in cigarette smoke

This paper discusses the use of carboxylated single-walled carbon nanotube as a general nanofilter platform for the removal of acrolein carcinogen from cigarette smoke. The analyses carried out in the detailed study of the electronic and structural effects of the adsorption of acrolein onto COOH loaded on single-walled carbon nanotube under the density functional theory framework. The results of Bader theory of atoms in molecules, natural bond orbital, molecular potential electron surface and density of state confirm the potential application of the suggested nanofilter platform.

The Interaction of Acrolein with Pristine and N-doped TiO2 Anatase Nanoparticles: A DFT Study.

Density functional theory calculations were carried out in order to study the effects of the adsorption of acrolein molecule on the structural and electronic properties of TiO2 anatase nanoparticles. The ability of pristine and N-doped TiO2 anatase nanoparticles to recognize toxic acrolein (C3H4O) molecule was surveyed in detail. It was concluded that acrolein molecule chemisorbs on the N-doped anatase nanoparticles with large adsorption energy and small distance with respect to the nanoparticle. The results indicate that the adsorption of acrolein on the N-doped TiO2 is energetically more favorable than the adsorption on the pristine one, suggesting that the N doping can energetically facilitate the adsorption of acrolein on the N-doped nanoparticle. It means that the N-doped TiO2 nanoparticle can react with acrolein molecule more efficiently. The interaction between acrolein molecule and N-doped TiO2 can induce substantial variations in the HOMO/LUMO molecular orbitals of the nanoparticle, changing its electrical conductivity which is helpful for developing novel sensor devices for the removal of harmful acrolein molecule. The large overlaps in the projected density of states spectra reveal the formation of chemical bond between two interacting atoms. Charge analysis based on Mulliken charges indicates that charge is transferred from the acrolein molecule to the TiO2 nanoparticle.

Adsorption of acrolein, propanal, and allyl alcohol on Pd(111): a combined infrared reflection-absorption spectroscopy and temperature programmed desorption study.

Atomistic-level understanding of the interaction of α,β-unsaturated aldehydes and their derivatives with late transition metals is of fundamental importance for the rational design of new catalytic materials with the desired selectivity towards C[double bond, length as m-dash]C vs. C[double bond, length as m-dash]O bond partial hydrogenation. In this study, we investigate the interaction of acrolein, and its partial hydrogenation products propanal and allyl alcohol, with Pd(111) as a prototypical system. A combination of infrared reflection-absorption spectroscopy (IRAS) and temperature programmed desorption (TPD) experiments was applied under well-defined ultrahigh vacuum (UHV) conditions to obtain detailed information on the adsorption geometries of acrolein, propanal, and allyl alcohol as a function of coverage. We compare the IR spectra obtained for multilayer coverages, reflecting the molecular structure of unperturbed molecules, with the spectra acquired for sub-monolayer coverages, at which the chemical bonds of the molecules are strongly distorted. Coverage-dependent IR spectra of acrolein on Pd(111) point to the strong changes in the adsorption geometry with increasing acrolein coverage. Acrolein adsorbs with the C[double bond, length as m-dash]C and C[double bond, length as m-dash]O bonds lying parallel to the surface in the low coverage regime and changes its geometry to a more upright orientation with increasing coverage. TPD studies indicate decomposition of the species adsorbed in the sub-monolayer regime upon heating. Similar strong coverage dependence of the IR spectra were found for propanal and allyl alcohol. For all investigated molecules a detailed assignment of vibrational bands is reported.

Acrolein Adsorption on Graphyne Nanotube: A Density Functional Theory Study

We have used density functional theory to investigate the possibility of using graphyne nanotubes for acrolein detection. Adsorption of acrolein on the armchair and zigzag nanotubes based on α-graphyne was studied. The results show that acrolein is physisorbed on graphyne nanotubes with large adsorption distance, small adsorption energy, and small charge transfer. Calculations of the electronic band structures and density of states indicate that acrolein adsorption has a considerable effect on the electronic properties of graphyne nanotubes. These nanotubes with metallic and semiconducting properties become n-type semiconductors with acrolein adsorption due to the charge transfer from molecule to graphyne nanotubes. Our results suggest the graphyne nanotubes as promising sensors for detection of acrolein.

Density functional study of acrolein adsorption on Pt (111)

The electronic structure and bonding of acrolein (propenal) adsorption on Pt (111) were studied by density functional calculations (DFT). We optimized different adsorption configurations on the surface using the VASP code. The energetic study indicates that acrolein trans isomers are less stable on the Pt surface than cis configurations, which have a similar stability in all cases. We found that the inclusion of Van der Waals (vdW) corrections does not change the obtained adsorption geometries or preferential sites relative energies. We also analyzed the evolution of the chemical bonding changes in the adsorbate and the metal surface by crystal orbital overlap population (COOP) and overlap population (OP) analysis of selected bonds. Except for the η1 configuration, the adsorption of acrolein on the surface is mainly due to the formation of C–Pt bonds. We also found that the acrolein C pz orbital, perpendicular to the surface, play an important role in the adsorption, as well as Pt pz and dz2 orbitals, whose lobes are well oriented to overlap with the adsorbate orbitals.

The adsorption of acrolein on a Pt (1 1 1): A study of chemical bonding and electronic structure

The adsorption of acrolein on a Pt (111) surface was studied using ab-initio and semiempirical calculations. Geometry optimization and densities of states (DOS) curves were carried out using the Vienna Ab-initio Simulation Package (VASP) code. We started our study with the preferential geometries corresponding to the different acrolein/Pt (111) adsorption modes previously reported. Then, we examined the evolution of the chemical bonding in these geometries, using the crystal orbital overlap population (COOP) and overlap population (OP) analysis of selected pairs of atoms. We analyzed the acrolein intramolecular bonds, Pt (111) superficial bonds and new moleculesurface formed bonds after adsorption. We found that PtPt bonds interacting with the molecule and acrolein CO and CC bonds are weakened after adsorption; this last bond is significantly linked to the surface. The obtained CPt and OPt OP values suggest that the most stable adsorption modes are η3-cis and η4-trans, while the η1-trans is the less favored configuration. We also found that C pz orbital and Pt pz and dz2 orbitals participate strongly in the adsorption process.

Dehydration of glycerol on H-MFI zeolite investigated by FT-IR

Dehydration of adsorbed glycerol on H-MFI zeolite was investigated by FT-IR. Dehydration of glycerol was confirmed to occur at 353 K. A comparison of the adsorption of acrolein on amorphous silica and on H-MFI suggests that the product on H-MFI upon dehydration of glycerol was acrolein. Although two reaction pathways in which the OH groups on C1 and C2 of glycerol dehydrate were suggested in the acid-catalyzed dehydration of glycerol, the pathway in which the OH groups on C2 dehydrate was found to proceed selectively on H-MFI.

Adsorption of acrolein on single-crystal surfaces of silver: Density functional studies

Silver selectively catalyzes the hydrogenation of the C O group of α, β-unsaturated aldehydes, indicating preferential adsorption-induced activation of this bond compared to the adjacent C C bond. Using a density functional method and periodic slab models, we studied the propensity of the flat Ag(1 1 0) and the stepped Ag(2 2 1) surfaces to activate the C O bond of adsorbed acrolein. Our calculations show acrolein to interact only weakly with all adsorption sites under study (by at most 35 kJ mol −1), resulting in very limited bond activation. Therefore, we conclude that other active sites on silver catalysts participate in the experimentally observed selective hydrogenation.

Coverage Dependent Adsorption of Acrolein on Pt(111) from a Combination of First Principle Theory and HREELS Study

A combination of GGA total-energy calculations and vibrational spectra simulations with HREELS experiments is reported to obtain new insights in the stable adsorption modes of the acrolein molecule on the Pt(111) surface. The simulations of the EELS spectra have allowed us to interpret the evolution of the experimental spectra, as a function of gas exposure. A strongly bound and coverage dependent chemisorption structure is shown. The 1 L spectrum has been assigned to a low coverage η3-cis and η4-trans mixed phase, with the molecule lying flat on the surface and interacting by both CC and CO bonds. The modified spectrum for an exposure of 2 L is associated with a change in the molecule adsorption structure toward a high coverage η2-cis and η2-trans form on the surface in complete agreement with the DFT total energy results.

Characterisation of the structure of adsorbates: An in situ DRIFTS-study of the partial oxidation of unsaturated aldehydes on Mo/V oxide catalysts

Mo/V oxides are interesting catalyst materials for the selective partial oxidation of unsaturated aldehydes (acrolein and methacrolein) to the corresponding carboxylic acids. Two catalyst systems — a mixed oxide and a heteropolyacid salt — were investigated by in situ DRIFT-spectroscopy. Using a novel DRIFTS cell, in which both the catalyst powder and the reference (KBr) were in the same reaction chamber, we are able to detect different adsorbates of (meth)acrolein and (meth)acrylic acid under reaction gases. The investigations showed that in the case of the adsorption of acrolein and methacrolein a significant difference in the structure of corresponding adsorbates could not be proved. This indicates that the reaction mechanism of the selective partial oxidation should be the same for both aldehydes. With these kind of investigations we gain access to a deeper insight into the reaction mechanism.

In-Situ Nonlinear Optical Studies of Photopolymerization of Gas Phase Acrolein onto Metallic Substrates

The kinetics of the photopolymerization of gas phase acrolein onto gold surfaces were studied by monitoring the surface reaction dynamics and the gas phase kinetics in-situ and in real time. A technique based on surface second harmonic generation (SSHG), a second-order nonlinear optical process, was developed to monitor the surface second-order nonlinear susceptibility, which was related to the fraction of unreacted monomer coverage on the surface during ultraviolet (UV) irradiation. The adsorption of acrolein onto the gold surface was also monitored using SSHG. It was found that the second harmonic signal at the surface decreased as a result of adsorption of acrolein and that the adsorption was an irreversible process. Upon UV irradiation, the second harmonic signal was found to decrease immediately as a result of the decrease in the surface monomer coverage, while an induction period was observed in the gas phase by vapor pressure measurements. The surface reaction rate was found to be first-order in surface monomer concentration, one-half-order in light intensity, and independent of the gas pressure in the range of partial pressure studied (61-152 Torr). The results suggested that polymerization took place initially at the surface-adsorbed layer. The existence of a metal surface may enhance the formation of free radicals on the surface-adsorbed layer and result in the selective photopolymerization on the metal surface. After the formation of a polymer layer on the gold surface, the photopolymerization was found to take place mainly in the gas phase. The apparent rate of the gas phase polymerization was found to be first-order in the gas pressure and one-half-order in light intensity.

Surface reactions of acrolein and propionaldehyde on cuprous oxide(100): nonselective oxidation and enolate-mediated side reactions to C3 products

The adsorption of acrolein and propionaldehyde on the polar, Cu + -terminated Cu 2 O(100) surface was investigated using X-ray photoelectron spectroscopy (XPS) and thermal desorption spectroscopy (TDS). The major reaction products observed for both aldehydes were nonselective oxidation products (CO, CO 2 , and H 2 O). Propene and acrolein were also detected as minor reaction products during propionaldehyde thermal desorption. Additionally, propene and propionaldehyde were detected as minor products during the reaction of acrolein with preadsorbed hydrogen. The coincident desorption of the propionaldehyde, acrolein, and propene from either acrolein and preadsorbed hydrogen or propionaldehyde adsorption suggests that a common surface intermediate is involved in these minor side reactions

V2O5/TiO2 oxidation catalysts, IV. Adsorption of acrolein on sodium-containing systems

Adsorption of acrolein on vanadia/titania catalysts fits a polymerization kinetics if Na−V compounds are not present or the vanadium content is lower than that corresponding to formation of a monolayer of vanadia on the titania support.

Catalytic oxidation of acrolein to acrylic acid over a molybdenum-vanadium catalyst

By the method of gas chromatography it has been found that the adsorption of acrolein takes place without dissociation whereas acrylic acid is adsorbed dissociatively. The adsorption of water vapor proceeds also dissociatively and results in increasing the number of the Bronsted acid centers. The presence of water vapor has a positive effect on the desorption rate of acrylic acid and a negative effect on the reoxidation rate of the catalyst.