Hydrogenation Of Cinnamaldehyde Research Articles

Highly dispersed Pd nanoparticles confined in ZSM-5 zeolite crystals for selective hydrogenation of cinnamaldehyde

Selective hydrogenation of α,β-unsaturated aldehyde catalyzed by supported Pd nanoparticles (NPs) is challenging, especially under harsh reaction conditions. Here, we report a facile method to prepare a catalyst composed of highly dispersed Pd NPs (∼2.6 nm) confined in zeolite ZSM-5 crystals. When used in the hydrogenation of cinnamaldehyde, the prepared catalyst ([email protected]) exhibited excellent performance for the selective production of hydrocinnamaldehyde (HCAL) due to the confinement effect. Compared with the traditional supported Pd catalyst prepared by impregnation, [email protected] showed a 2.5-fold enhancement in the HCAL selectivity (73% vs. 30%). Liquid adsorption combined with infrared spectroscopy characterization revealed that compared with the traditional catalyst, [email protected] adsorbed much less reactant as well as product molecules and desorbed the generated HCAL quickly, thereby suppressing the formation of by-products and leading to high selectivity of HCAL.

Pt-Modified MoO3 catalyst for the electrochemically selective CO hydrogenation of cinnamaldehyde.

The electrocatalytic selective hydrogenation of biomass-derived molecules is an important approach for synthesizing value-added chemicals. Herein, we synthesized carbon-supported platinum-modified molybdenum oxide nanoparticles (Pt-MoO3/C) to efficiently catalyze cinnamaldehyde (CAL) to cinnamyl alcohol. DFT results unveiled that the modified Pt regulated the surface electronic structure, favourable for the vertical adsorption of CAL.

Size Effect of Spinel Co0.5fe0.5al2o4 Supported Pt Catalysts for the Selective Hydrogenation of Cinnamaldehyde

Size Effect of Spinel Co0.5fe0.5al2o4 Supported Pt Catalysts for the Selective Hydrogenation of Cinnamaldehyde

Improvement and regeneration of Co-B amorphous alloy nanowires for the selective hydrogenation of cinnamaldehyde.

One-dimensional Co-B amorphous alloy nanowires (NWs) were prepared using surfactant as a template and were treated with plasma to study the effect of different treatment times on the essential physical and chemical properties of the catalyst. The study showed that plasma with a certain amount of strength will not change the morphology and amorphous structure of the NWs within the chosen treatment time. It could, however, modify the electronic structure and active sites of the catalyst surface, increase its specific surface area and H2 adsorption capacity, and also improve the selective hydrogenation performance of cinnamaldehyde. Most of all, plasma treatment could also play an important role in the reuse of catalysts. After several recycling reactions, plasma treatment on Co-B amorphous alloy NWs could regenerate their high catalytic activity. This work provides a novel method for preserving the high catalytic activity and stability of amorphous alloy nanomaterials, as well as for increasing their reusability.

Defect engineering and spilt-over hydrogen in Pt/(WO3–TH2) for selective hydrogenation of CO bonds

The effect of defects in pre-treatment WOx on the catalytic performance of selective hydrogenation of cinnamaldehyde to cinnamyl alcohol has been revealed.

Cinnamaldehyde hydrogenation over carbon supported molybdenum and tungsten carbide catalysts.

The potential of carbon supported Mo and W carbides to replace Pt is shown for the hydrogenation of cinnamaldehyde. Although the carbide catalysts are 4-6 times less active, both the carbides and Pt are selective towards CC hydrogenation. Unlike Pt, the carbides additionally form β-methylstyrene.

Efficient electrocatalytic hydrogenation of cinnamaldehyde to value-added chemicals

A system for electrocatalytic hydrogenation of cinnamaldehyde to value-added chemicals with high faradaic efficiency, selectivity, conversion and stability.

Low-temperature reduction of bio-based cinnamaldehyde to α,β-(un)saturated alcohols enabled by a waste-derived catalyst

A waste eggshell-derived catalyst (CaO-900) was facilely prepared and exhibited high efficiency in selective hydrogenation of bio-based cinnamaldehyde (CAL) to cinnamyl alcohol (COL) with 97% yield at 30 °C. By simply adjusting reaction temperature and time, CAL could be completely converted to 3-phenylpropanol. The predominant catalytic performance of CaO-900 could be attributed to its high alkalinity and large specific surface area. In situ Raman and theoretical calculations indicated that the priority of hydrosilylation toward CAL played a crucial role in the control of product distribution. In addition, the CaO-900 catalyst showed good recyclability.

In‐Situ Incorporation of Pt Nanoparticles on Layered Double Hydroxides for Selective Conversion of Cinnamaldehyde to Cinnamyl Alcohol

AbstractDesigning efficient and low‐cost catalysts for generation of cinnamyl alcohol (CMO) from cinnamaldehyde (CMA) hydrogenation is of practical value. Herein, layered double hydroxide supported Pt nanoparticles (Pt‐s/LDH) were prepared by in‐situ reduction of PtCl62− in PtCl62−‐LDH with ethylene glycol, and the PtCl62− was intercalated in LDH by ion‐exchange method. The characterization results verify that small Pt nanoparticles are uniformly distributed on LDH with average diameter of 1.9 nm and narrow size distribution. The prepared Pt‐s/LDH catalyst exhibits excellent catalytic performance for selective hydrogenation of CMA under relatively mild reaction conditions (80 °C, 2 MPa H2) with high turnover frequency (TOF) (0.574 s−1) and CMA conversion (92.6 %). Furthermore, the CMA conversion rate and CMO selectivity remain almost unchanged after the fourth run compared with the results of the first run. This study provides an effective route for synthesis of efficient and stable LDH‐supported metal catalysts.

Single palladium atoms stabilized by β-FeOOH nanorod with superior performance for selective hydrogenation of cinnamaldehyde

Single palladium atoms stabilized by β-FeOOH nanorod with superior performance for selective hydrogenation of cinnamaldehyde

Hydrogen solubility in biphasic liquid reaction mixture of cinnamaldehyde hydrogenation: experimental and mathematical modeling study

Hydrogen solubility in biphasic liquid reaction mixture of cinnamaldehyde hydrogenation: experimental and mathematical modeling study

Insight into the role of iron in platinum-based bimetallic catalysts for selective hydrogenation of cinnamaldehyde

Selective hydrogenation of cinnamaldehyde (CAL) toward cinnamyl alcohol (COL) is an extremely important and challenging reaction. Herein, a series of PtxFey-Al2O3 bimetallic catalysts with varied Pt to Fe ratios were prepared by incipient wetness impregnation method. The introduction of Fe significantly modifies the electronic and surface properties of Pt, which clearly enhances the C=O hydrogenation selectivity. Among all the catalysts, Pt3Fe-Al2O3 displays the best catalytic performance and the conversion of CAL is 96.6% with 77.2% selectivity of COL within 1 h. In addition, Pt3Fe-Al2O3 had excellent reusability with 76% COL selectivity after five runs of the recycle process. Further characterization of the fresh, used and cycled catalysts revealed that the structure and electronic state of the synthesized PtxFey-Al2O3 are unchanged after hydrogenation reaction. The identical-location transmission electron microscopy (IL-TEM) results revealed that the interaction between the nanoparticles and the supports was strong and the catalyst was relatively stable.

Selective hydrogenation of cinnamaldehyde using palladium based bimetallic catalysts Pd-M/TiO2 (M=Cu, Ag and Au)

Pd based bimetallic catalysts, Pd-M, (M=Cu, Ag, and Au) supported on TiO 2 P-25, have been prepared by chemical reduction with glucose and characterized by XRD, TEM, XPS, DRS, TPR and H 2 TPD. Activity for the conversion of cinnamaldehyde (CAL) and selectivity to hydro-cinnamaldehyde (HCAL), cinnamyl alcohol (COL) and hydrocinnamyl alcohol (HCOL) have been evaluated in the temperature range of 120-140°C for 1 hr and 10 bar hydrogen pressure. For comparison, monometallic Cu, Ag and Au (1% w/w in each case) catalysts supported on TiO 2 P-25 have been prepared and evaluated. DRS and XPS studies reveal nanoscale alloy formation and re-distribution of charges in bimetallic catalysts. Bimetallic Pd-Cu displays higher CAL conversion compared to Pd-Ag and Pd-Au. Besides the favorable electronic and ensemble effects, availability of reactive hydrogen on Pd-Cu, as revealed by the lowest hydrogen desorption temperature, is an additional factor that contributes towards the higher activity of Pd-Cu. Bimetallic catalysts are stable up to five reaction cycles, without any loss of Pd or structural integrity.

Identification and Insight into the Role of Ultrathin LDH‐Induced Dual‐Interface Sites for Selective Cinnamaldehyde Hydrogenation

AbstractFocusing on the simultaneous enhancement of activity and selectivity in α, β‐unsaturated aldehyde hydrogenation, we designed and prepared an ultrathin CoAl‐LDH supported Pt catalyst. A series of technologies revealed the ultrathin CoAl‐LDH support possesses the characteristic of dual defects, oxygen vacancy (VO) and cobalt vacancy (VCo). Then, two kinds of vacancy related interface sites were identified, namely Pt−VO−Coδ+ and Pt−VCo−OHδ−. Compared with the bulk catalyst, the ultrathin catalyst exhibits both enhanced intrinsic activity and C=O bond selectivity under the synergistic effect of the dual interface sites. Specifically, the Pt−VO−Coδ+ interface site changes the adsorption mode of cinnamaldehyde and promotes the activation of C=O bonds, thus leading to the improved cinnamyl alcohol selectivity. The H atoms of the Pt−VCo−OHδ− interface site participate in the hydrogenation process, which facilitates the mobility of active hydrogen and therefore promotes the intrinsic activity. More importantly, the ultrathin catalyst shows good reusability.

Spatial Location and Microenvironment Engineering of Pt-CeO2 Nanoreactors for Selective Hydrogenation of Cinnamaldehyde to Cinnamyl Alcohol

More than 25% of chemical transformations involve at least one hydrogenation step. Selective hydrogenation of unsaturated aldehydes is an essential process in the industrial production of pesticide...

Active and Recyclable Gold Metal Nanoparticles Catalyst Supported on Nitrogen-Doped Mesoporous Carbon for Chemoselective Hydrogenation of Cinnamaldehyde to Cinnamyl Alcohol.

Several supported gold metal catalysts with different Au nanoparticles sizes were prepared and evaluated for the chemoselective hydrogenation of cinnamaldehyde (CA) to cinnamyl alcohol (CAL). To investigate the structure-activity relationship, stability of catalyst, heterogeneity and recyclability, the structural characteristics of materials and Au catalysts (fresh and spent catalysts) were studied by employing variety of physico-chemical techniques. The interrelationship among Au nanoparticles size (nm) with turnover frequency (h-1 ) of Au catalysts has also been explored. Among the various Au catalysts tested, nitrogen-doped mesoporous carbon (NMC) supported Au catalyst having homogeneously dispersed (78.8%) Au nanoparticles (1.6 nm) synthesized by sol-immobilization method (Au-NMC-SI) demonstrated improved catalytic activity affording 78% CAL selectivity and 94.2% CA conversion without using any promoter. Moreover, Au-NMC-SI catalyst exhibited good recyclability and stability. The catalyst synthesis approach described in this investigation opens up a novel strategy for the design of highly efficient metal nano-catalysts supported on NMC materials.

Selective hydrogenation of cinnamaldehyde to cinnamyl alcohol over palladium/zirconia in microwave protocol

Hydrogenation of aldehydes (RHO) is one of the frequently used reactions in organic synthesis and pharmaceuticals industries. In this contribution, we have synthesized control shaped and nano-sized tetragonal zirconia (t-ZrO2), palladium supported on zirconia (Pd/t-ZrO2) and nickel promoted palladium supported on zirconia (Ni-Pd/t-ZrO2) though modified microwave irradiation method. All the prepared samples were characterized by Transmission Electron Microscopy (TEM), Scanning Electron Microscopy (SEM), Energy Dispersive X-ray Spectroscopy (EDX), X-ray Diffractometry (XRD), Thermal Gravimetric Analysis (TGA), Brunauer-Emmett-Teller (BET) surface area and pore size analysis, and Fourier Transform Infrared Spectroscopy (FT-IR). Theoretical calculation (DFT) revealed high interaction of Pd with t-ZrO2(101) surface. Furthermore, adsorption energy, support relaxation and charge transfer studies confirmed the stability of Pd on t-ZrO2(101) surface. The catalytic activity of catalysts was tested for cinnamaldehyde (CAL) hydrogenation in a modified microwave reactor. The comparative study of microwave irradiated (MW) and conventional heating (C-Heating) systems show supremacy of MW over C-Heating by a factor of 46% under optimal reaction parameters for Pd/t-ZrO2 catalyst. The stability, life span, conversion and selectivity of Pd/t-ZrO2 under MW system suggest the applicability of the catalysts for a variety of organic hydrogenation reactions.

Playing on 3D spatial distribution of Cu-Co (oxide) nanoparticles in inorganic mesoporous sieves: Impact on catalytic performance toward the cinnamaldehyde hydrogenation

The preparation of supported bimetallic materials based on transition metals has attracted much interest since their use as catalysts towards hydrogenation processes for the production of fine chemicals or environmental depollution processes. The synthesis procedure proposed in this study allows to obtain bimetallic materials with high dispersion of the active sites, control of the chemical composition and localization as well as good thermal resistance against sintering. In this line, a series of materials based on Cu and Co supported on SBA-15 were prepared by the optimization of the drying step during incipient wetness impregnation, the ratio of Cu-Co was studied and the monometallic materials were used for comparison. The physico-chemical properties of freshly calcined and reduced materials were investigated by ICP-EOS, nitrogen physisorption, ex-situ and in-situ XRD, TEM-EDX, TPR and XPS. The materials showed improved dispersion at low copper ratio, due to the stabilization of CuxCo(1-x)Co2O4 spinel phase, promoting a high dispersion of confined NPs of 9 nm within the large pores of the SBA-15. Subsequent stabilization of the Cu and Co NPs is observed by in situ-XRD, and the collected HAADF micrographs clearly evidence a high dispersion of the copper within the bimetallic NPs. However, when copper is exceeding the CuCo ratio of 4:1, larger NPs of CuO located outside the silica mesopores are observed. Subsequent catalytic performances were investigated in the hydrogenation reaction of cinnamaldehyde (CNA), in two different pressure regimes (1 bar and 10 bars). For the reaction under pressure, CuCo1:4 showed the highest conversion with 67 mol % after 150 min of reaction, while the selectivity to the cinnamyl alcohol (CNOL) was of 47 mol %. The same catalyst showed a conversion of 99 mol % in atmospheric pressure after 24 h of reaction and the selectivity to CNOL reached 72 mol %. Such results confirm that our modified IWI protocol using mild drying step is valuable towards the preparation of confined bimetallic nanoparticles within mesoporous sieves. High stability of such confined nanoparticles allow reduction of the active elements up to the metallic state, which strongly promotes the catalytic performance towards CNA hydrogenation reaction.

Recyclable Ir Nanoparticles for the Catalytic Hydrogenation of Biomass-Derived Carbonyl Compounds

The valorisation of biomass-derived platform chemicals via catalytic hydrogenation is an eco-friendly tool which allows us to recover bio-based building blocks and produce fine chemicals with high industrial appeal. In the present study, a novel surfactant-type triazolyl-thioether ligand was prepared, showing excellent catalytic activity in the presence of bis(1,5-cyclooctadiene)diiridium(I) dichloride [Ir(COD)Cl]2 for the hydrogenation of furfural, cinnamaldehyde, levulinic acid, 5-hydroxymethylfurfural, vanillin, and citral. Easy recovery by liquid/liquid extraction allowed us to recover the catalyst, which could then be efficiently recycled up to 11 times for the hydrogenation of furfural. In-depth analysis revealed the formation of spherical structures with metal nanoparticles as big as 2–6 nm surrounded by the anionic ligand, preventing iridium nanoparticle degradation.

On the role of bismuth as modifier in AuPdBi catalysts: Effects on liquid-phase oxidation and hydrogenation reactions

There is much about the action of bismuth within heterogeneous catalysis that still require a deeper understanding. We observed that, when Bi was added to AuPd bimetallic nanoparticles (NPs) supported on activated carbon, Bi affected the activity and significantly alters the selectivity in two model liquid phase reactions, namely the oxidation of cinnamyl alcohol and the hydrogenation of cinnamaldehyde. A combination of transmission electron microscopy and X-ray absorption spectroscopy provided a detailed characterization of trimetallic AuPdBi systems. We propose that the introduction of bismuth on AuPd NPs results in a partial blockage of most active sites, limiting the occurrence of consecutive reactions.