Hydrogenation Of Cinnamaldehyde Research Articles

Supramolecular pre‐organisation rhodium and iridium metal complexes within M12L24 self‐assembled nanospheres for the confined synthesis Rh/Ir alloyed nanoparticles

Controlling the size and composition of metal nanoparticles is of considerable interest, as these are essential to their catalytic properties. We report the controlled synthesis Rh nanoparticles by preorganisation of metal complexes inside Pt12L24 nanospheres based on complementary hydrogen bonds before the reduction step that leads to nanoparticle formation. The encapsulated RhI complexes (Rh‐s @ G‐sphere) led to reasonable size control (2.8 ± 0.9 nm). We also report the formation of Rh‐Ir alloyed nanoparticles with varying Rh/Ir compositions. These heterometallic particles were evaluated in the hydrogenation of cinnamaldehyde (7) as a probe reaction. Besides a high activity in this probe reaction, the Rh particles also catalyzed the conversion of the solvent (CH3CN). The formed basic amine leads to follow‐up reactions of the product and compatibility issues with the hosting nanosphere. The solvent hydrogenation was effectively suppressed by using the Rh:Ir alloyed nanoparticles, provided that they contain >66% Ir. The Rh:Ir alloyed nanoparticles displayed high catalytic activity, reaching optimal selectivity and activity at an 8:16 ‐ Rh:Ir ratio. The combined catalytic results illustrate that pre‐organisation of the metal complexes in the nanosphere before the reduction with hydrogen effectively facilitates the formation of Rh:Ir alloyed nanoparticles.

Mechanochemistry Strategy in Metal/Fe3O4 with High Stability for Superior Chemoselective Catalysis.

While noble metal nanoparticles (MNPs) exhibit remarkable performance in heterogeneous catalysis and their incorporation into crystalline materials can fully exploit the combined advantages of both, achieving introduction of nanoclusters during material crystallization, precisely controlling their interactions, and facilitating catalyst recovery remain significant challenges. In this study, Au NPs, Pt NPs, and Pd NPs are supported on magnetic Fe3O4, enabling the modulation of the electronic states of MNPs by adjusting the introduction method. Notably, the catalysts (Pt/Fe3O4, Au/Fe3O4, and Pd/Fe3O4) demonstrate excellent activity in chemoselective reactions: cinnamaldehyde (CAL) hydrogenation (turnover number: 20,135 h-1), nitrobenzene hydrogenation (with 99.9% selectivity for major nitrobenzene derivatives and robust stability at 19 cycles), and 3-nitrophenylacetylene (3-NPA) hydrogenation (yielding up to 98.4% 3-aminophenylacetylene (3-APA)), in stark contrast to the low activity of comparable catalysts. This paper proposes a novel and versatile solid-phase mechanochemistry strategy that achieves precise control over the microenvironment of MNPs while maintaining their inherent activity, thereby offering an effective approach to develop catalysts with high specificity and easy recovery capabilities.

CoZnyB/Nb2CTx(MXene) for cinnamaldehyde hydrogenation to cinnamyl alcohol: Effects of Zn

Amorphous cobalt boride (CoB) catalysts have superior CO selectivity for cinnamaldehyde (CAL) hydrogenation and low activity. This work prepared CoZnyB/Nb2CTx(MXene) catalysts with different Zn ratios (y=0, 0.025, 0.05, 0.075, and 0.1) via a wet reduction method, which were subsequently utilized in the selective hydrogenation of CAL to cinnamyl alcohol (COL). The CoZn0.05B/Nb2CTx catalyst exhibited superior low-temperature activity, with 91.4 % CAL conversion and a 66.3 % COL yield. SEM and XPS analyses further revealed that Zn enhanced the catalytic activity by generating smaller amorphous alloy particles and exposing more Co0 active sites. Furthermore, the NH3-TPD and adsorbed pyridine DRIFTS results showed that Zn modified the surface acidity of the CoZnyB/Nb2CTx catalyst by generating both Lewis acid sites and Brønsted acid sites, which can facilitate the adsorption of CAL. This work demonstrated that Zn can increase the number of exposed active sites and modify the surface acid properties of amorphous CoB catalysts.

Core/Shell Metal Oxides@MIL-53(Al) Nanoparticles as Catalyst for the Selective Hydrogenation of Cinnamaldehyde

Core/Shell Metal Oxides@MIL-53(Al) Nanoparticles as Catalyst for the Selective Hydrogenation of Cinnamaldehyde

Ordered macroporous superstructure of defective carbon adorned with tiny cobalt sulfide for selective electrocatalytic hydrogenation of cinnamaldehyde

Electrocatalytic selective hydrogenation of α,β-unsaturated aldehydes represents a sustainable approach to achieve the highly value-added products, while the kinetic and selectivity are still greatly depend on the elaborated nanostructure design of electrocatalysts. In this study, by the sulfidation of ordered macroporous ZIF-67 single crystals, the ordered macroporous superstructure of carbon with abundant edge defects was achieved, where the tiny CoS nanoparticles are favorably anchored with homogeneous dispersion. Impressively, this superstructured electrocatalyst exhibited a remarkable activity towards the selective hydrogenation of cinnamaldehyde to hydrocinnamaldehyde with water as hydrogen source, acquiring the highest selectivity up to 92.1 % at 12 mA cm–2 with a cinnamaldehyde conversion of 89.6 %. The further experimental analysis combined with the density functional theory calculations revealed that the preferential absorption of CC over the tiny CoS nanoparticles with the maximal site accessibility, and the facilitated mass and charge transfer enabled by the ordered macropore engineering, jointly contribute to the excellent electrocatalytic performance. Additionally, this electrocatalyst also exhibited good expandability for several kinds of α,β-unsaturated aldehydes/ketones with different functional groups. Our findings offer new insights into the electrocatalytic selective hydrogenation, emphasizing the role of ordered pore engineering in constructing favorable microenvironments and synergizing active sites.

MIL-101(Cr) entrapped polyol-synthesized iron promoted platinum bimetallic nanoparticles system for synergistic selective hydrogenation of cinnamaldehyde

The interfacial characteristics of platinum (Pt) metal catalysts can be systematically regulated by interacting them with electropositive metals, leading to synergistic interactions for extensive catalytic applications. In this study, an evenly dispersed polyol-synthesized iron (Fe)-promoted Pt bimetallic nanoparticle (BNPs) system was embedded in MIL-101(Cr). The PtFe2@MIL-101(Cr) catalyst unveiled remarkable activity (86%) and selectivity (89%) for the superior hydrogenation of the targeted CO bond of cinnamaldehyde (CAL). The exceptional hydrogenation performance can be credited to the interplay of the geometric and electronic properties arising from charge shuttling between Fe and Pt within the homogenously distributed Pt–Fe bimetallic nanoparticle system. The experimental results indicate enhanced valence electrons in the Pt d-band through the mutual synergetic interface between the Pt and Fe BNPs. Consequently, these Fe–Pt sites functioned as interfacial electrophilic and nucleophilic (Lewis acid-base) sites, enhancing H2 activation and facilitating CO bond conversion to yield unsaturated cinnamal alcohols (COL). Additionally, the narrow pores of MIL-101(Cr) encapsulating the Pt–Fe BNPs induced steric hindrance, allowing only CO bond hydrogenation. Furthermore, the PtFe2@MIL-101(Cr) catalyst maintained its optimal hydrogenation performance over five cycles, demonstrating no substantial loss in either CAL conversion or COL yield, thus endorsing the universal practical applicability of the catalyst.

Hydrophobic and porous Fe-Pdb coordination framework structure supported Pt-Fe nanoparticles catalyst for enhanced chemoselective hydrogenation of cinnamaldehyde

The selective hydrogenation of cinnamaldehyde to cinnamyl alcohol has remained a ponding challenge due to competitive hydrogenation reactions between CC and CO groups. In this work, a hydrophobic and porous Fe and 3,3′-(pyridine-3,5-diyl)-dibenzoic acid coordination framework structure (Fe-Pdb(CFs)) was employed to support Pt-Fe nanoparticles and synthesize a high-performance Pt-Fe/Fe-Pdb(CFs) heterogeneous catalyst. The reactivity activity could be greatly improved by introducing electrophilic sites and enhancing the enrichment effect of Fe-Pdb(CFs) material. Thus, the optimal cinnamaldehyde conversion reached approximately 88.9%, with a better selectivity of 85.8% towards cinnamyl alcohol at 60°C.

Effect of Pt/Co Ratio of Pt–Co Nanoparticles on Ionic Liquid-Modified SBA-15 for Selective Hydrogenation of Cinnamaldehyde

Effect of Pt/Co Ratio of Pt–Co Nanoparticles on Ionic Liquid-Modified SBA-15 for Selective Hydrogenation of Cinnamaldehyde

CNTs-promoted Co-Cu Catalyst for Efficient Synthesis of Cinnamyl Alcohol from Hydrogenation of Cinnamaldehyde

CNTs-promoted Co-Cu Catalyst for Efficient Synthesis of Cinnamyl Alcohol from Hydrogenation of Cinnamaldehyde

Pd-N-doped carbons for chemoselective hydrogenation of cinnamaldehyde: Unravelling the influence of particle size and support in multiphase batch and continuous-flow systems

The chemoselective hydrogenation of the CC bond of cinnamaldehyde (CAL) was investigated under batch and continuous flow conditions, by comparing the performance of two ad-hoc prepared palladium-based catalysts supported on N-doped carbons to that of a commercial Pd/C system. An impregnation (I) and a solution-mediated (S) protocols were used for the synthesis of the catalytic materials, Pd-N/Ci and Pd-N/Cs, respectively, in the presence of chitin as a precursor of the support. The S method afforded palladium nanoparticles of 2.0±0.5 nm, while by impregnation, a wider size distribution was achieved with particles mostly belonging to two groups displaying a mean radius of 3.0±0.5 nm and 8.4±0.5 nm, respectively. A parametric analysis of the hydrogenation reaction showed that both the reaction conditions and the nature of the catalysts played a role to steer the selectivity towards the formation of the desired product, 3-phenylpropanal (hydrocinnamaldehyde, HCAL). At 50 °C and 1 bar H2, in a triphasic (liquid-liquid-liquid) batch reactor where the catalyst was compartmentalized in an ionic liquid layer, Pd-N/Ci and commercial Pd/C were almost equally active and allowed to obtain HCAL in a 90–96 % selectivity at complete conversion. On the other hand, at the same T and p (50 °C/1 bar), Pd-N/Cs was more effective in the continuous-flow mode: the process was quantitative yielding HCAL with a selectivity and a productivity of 91 % of 16 mmol (gcat h)−1, respectively, while the catalyst proved highly stable showing no loss of activity over 300 min of time on-stream. The reaction environment, the size and dispersion of the metal active sites, and the nature of the catalyst support were major contributors to such results, acting synergistically to each other to tune the energetics of adsorption/desorption of reactants/products, of the interfacial interactions/ barriers, and in the last analysis, of the process kinetics/selectivity.

Fabrication of SBA-15-supported nanoscale Co3O4 and its use in the catalytic hydrogenation of cinnamaldehyde

Fabrication of SBA-15-supported nanoscale Co3O4 and its use in the catalytic hydrogenation of cinnamaldehyde

Co-Ti Bimetallic Complex-Induced Phase Modulation of Co@Black TiO2 for Catalytic Hydrogenation of Cinnamaldehyde.

Transition-metal-doped black titania, primarily in the anatase phase, shows promise for redox reactions, water splitting, hydrogen generation, and organic pollutant removal, but exploring other titania phases for broader catalytic applications is underexplored. This study introduces a synthetic approach using a Co-Ti bimetallic complex bridged by a 1,10-phenanthroline-5,6-dione ligand as a precursor for the synthesis of cobalt-doped black titania [Co@L2N@b-TiO2]. The synthesis involves precise control of pyrolysis conditions, yielding a distinct structure dominated by the rutile phase over anatase, with active cobalt encapsulated within a nitrogen-doped graphitic layer, primarily as Co0 rather than CoII and CoIII. The synthesized material is employed for the selective hydrogenation of cinnamaldehyde (CAL) to cinnamyl alcohol (COL) under industrially viable conditions. The efficiency and selectivity of Co@L2N@b-TiO2 was compared with other catalysts, including cobalt-doped rutile TiO2 (Co@r-TiO2), anatase TiO2 (Co@a-TiO2), and black titania (Co@b-TiO2) as well as materials pyrolyzed under different atmospheres and temperatures, materials with phenanthroline ligands, and materials lacking any ligands. The superior performance of Co@L2N@b-TiO2 is attributed to its high surface area, stable Co0 within the nitrogen-doped graphitic layer, and composition of rutile and anatase phases of TiO2 and Ti2O3 (referred to as RAT), along with the synergistic interaction between RAT and Co0. These factors significantly influence the efficiency and selectivity of COL over hydrocinnamaldehyde (HCAL) and hydrocinnamyl alcohol (HCOL), indicating potential for broader applications beyond catalysis, particularly in designing of black titania-based materials.

Dually functional NiSi intermetallic compounds for the efficient hydrogenation and oxidation of cinnamaldehyde

Intermetallic compounds (IMCs) are promising catalysts for upgrading biomass-derived platform chemicals. Herein, bifunctional NiSi IMCs catalysts were developed for the hydrogenation and oxidation of cinnamaldehyde (CAL). A solvent-free arc-melting method was employed for the synthesis of NiSi IMCs within 5 min. The NiSi IMCs catalysts afforded 99 % conversion of CAL and presented ∼ 71 % yield of 2-phenyl propanol and ∼ 34 % yield of benzaldehyde for the hydrogenation and base-free oxidation of CAL, respectively. Moreover, NiSi IMCs could be used for five runs without deactivation. Characterizations and theoretical calculation results indicated the formation of intermetallic structure and the existence of Si vacancy sites, which could not only facilitate the efficient hydrogenation of CAL but also expose NiOx species as catalytic centers for the oxidation of CAL, leading to the high performance and stability in both hydrogenation and oxidation process.

Continuous-flow hydrogenation of cinnamaldehyde over catalysts derived from modified CoAl4 layered double hydroxides incorporating Mn, Ni, Cu and Zn ions

Series of CoxM1-xAl4 layered triple hydroxides, LTHs were prepared as catalyst precursors for hydrogenation of biomass compound cinnamaldehyde under flow and batch reaction conditions. To this end, we have successfully extended the eco-friendly family of Al-rich layered double hydroxides (LDHs) by synthesizing MnAl4-LDHs, furthermore Co3Al-, Co2Al-LDHs were also exploited. Both the magnetic Co-rich and Al-rich reduced forms behaved as robust, efficient and reusable catalysts with significantly different selectivities correlated with their acid-base properties. Al-rich solids showed increased acidity and lower basicity resulting in high hydrocinnamaldehyde selectivity (∼75 %), while the Co-rich catalysts attested enhanced hydrocinnamyl alcohol production (∼80 % selectivity) due to their low acidity and high basicity (mapped by NH3/CO2 temperature programmed desorption tests). Incorporation of Mn, Ni, Cu and Zn ions generally decreased the total acidity of Al-rich catalysts, while their Lewis basicity largely increased: the highest was found for Mn, resulting in activity similar to that of Co-rich catalysts.

Precise regulation of Mo2N–TiO2 deposited Pt nanoparticles induced synergistic effect for the hydrogenation of cinnamaldehyde

The amalgamation of an appropriate cocatalyst is a proficient technique to expand the efficacy of precious Pt-based catalytic materials. In this study, Mo2N–TiO2 with regularly distributed Mo2N particles were simply prepared for the deposition of precious Pt nanoparticles (NPs). Numerous techniques were implemented to thoroughly explore, how synthesis method influence the bulk structural, interfacial and cata1ytic features of the as-prepared 3 wt%Pt/TiO2 and 3 wt%Pt/Mo2N–TiO2 catalytic materials. The catalytic results obviously show that the 3 wt%Pt/Mo2N–TiO2 catalyst has exceptional hydrogenation performance when compared to 3 wt%Pt/TiO2 catalyst. The 3 wt%Pt/Mo2N–TiO2 catalyst displayed high conversion (72.4 %) of cinnamaldehyde (CAL) with a maximum selectivity (82.1 %) towards CO bond. The excellent hydrogenation performance is attributed to the synergistic interaction taking place between Pt NPs and Mo2N entities of 3 wt%Pt/Mo2N–TiO2. Also, the enhanced standardized dispersal of Pt NPs on the Mo2N–TiO2 surface causes more exposed Pt0 sites on the 3 wt%Pt/Mo2N–TiO2 surface, which is productive for the improved activation and conversion of CO bond of CAL to yield COL. In addition, the 3 wt%Pt/Mo2N–TiO2 catalyst retained its higher catalytic activity for consecutive five successive rounds without substantial loss in either conversion or selectivity.

Schiff Base Functionalized Cellulose: Towards Strong Support-Cobalt Nanoparticles Interactions for High Catalytic Performances.

A new hybrid catalyst consisting of cobalt nanoparticles immobilized onto cellulose was developed. The cellulosic matrix is derived from date palm biomass waste, which was oxidized by sodium periodate to yield dialdehyde and was further derivatized by grafting orthoaminophenol as a metal ion complexing agent. The new hybrid catalyst was characterized by FT-IR, solid-state NMR, XRD, SEM, TEM, ICP, and XPS. The catalytic potential of the nanocatalyst was then evaluated in the catalytic hydrogenation of 4-nitrophenol to 4-aminophenol under mild experimental conditions in aqueous medium in the presence of NaBH4 at room temperature. The reaction achieved complete conversion within a short period of 7 min. The rate constant was calculated to be K = 8.7 × 10-3 s-1. The catalyst was recycled for eight cycles. Furthermore, we explored the application of the same catalyst for the hydrogenation of cinnamaldehyde using dihydrogen under different reaction conditions. The results obtained were highly promising, exhibiting both high conversion and excellent selectivity in cinnamyl alcohol.

Silica-modified Pt/TiO2 catalysts with tunable suppression of strong metal–support interaction for cinnamaldehyde hydrogenation

Tuning Strong Metal-support Interactions (SMSI) is a key strategy to obtain highly active catalysts, but conventional methods usually enable TiOx encapsulation of noble metal components to minimize the exposure of noble metals. This study demonstrates a catalyst preparation method to modulate a weak encapsulation of Pt metal nanoparticles (NPs) with the supported TiO2, achieving the moderate suppression of SMSI effects. The introduction of silica inhibits this encapsulation, as reflected in the characterization results such as XPS and HRTEM, while the Ti4+ to Ti3+ conversion due to SMSI can still be found on the support surface. Furthermore, the hydrogenation of cinnamaldehyde (CAL) as a probe reaction revealed that once this encapsulation behavior was suppressed, the adsorption capacity of the catalyst for small molecules like H2 and CO was enhanced, which thereby improved the catalytic activity and facilitated the hydrogenation of CAL. Meanwhile, the introduction of SiO2 also changed the surface structure of the catalyst, which inhibited the occurrence of the acetal reaction and improved the conversion efficiency of C=O and C=C hydrogenation. Systematic manipulation of SMSI formation and its consequence on the performance in catalytic hydrogenation reactions are discussed.

Design of Pt@Sn core–shell nanocatalysts for highly selective hydrogenation of cinnamaldehyde to prepare cinnamyl alcohol

The selective hydrogenation of cinnamaldehyde (CAL) to prepare cinnamyl alcohol (COL) is challenging as the unwanted hydrogenation of CC bond in CAL is thermodynamically more favorable than the hydrogenation of CO bond. We herein designed core–shell structured nanoparticles (NPs) that consisted of Pt cores and Sn shells to catalyze the CAL to COL conversion. By simply changing the amount of Sn precursor, we generated Pt@Sn NPs with different Sn shell thickness and catalytic performance. Among the samples, Pt@Sn/SiO2 with Pt/Sn of 1/1 achieved the highest CAL conversion (87.2 %) as well as the COL selectivity (95.4 %), which were 5-fold and 6-fold, respectively, higher than those of Pt/SiO2. This catalyst was also applicable to the hydrogenation of other α, β-unsaturated aldehyde and unsaturated carbonyl compounds. Both experiments and theoretical calculations indicated that the strong Pt-Sn interaction and the partial coverage of Pt by Sn facilitated their adsorption of CO bonds, thus enhancing the conversion of CAL and the selectivity towards COL.

Water-promoted selective hydrogenation of cinnamaldehyde over hydrotalcite-derived Co catalysts

Non-noble metal-catalyzed selective CO hydrogenation of α,β-unsaturated aldehydes to corresponding alcohols is chemically atom economic and practically feasible. This work reports hydrotalcite-derived Co-based catalysts for catalyzing aqueous phase selective hydrogenation reaction of cinnamaldehyde to cinnamyl alcohol. The structure characterizations demonstrate the phase transition from hydrotalcite to co-existed CoOx and metallic Co0 in the optimal Co2Al-H2-400 catalyst. It exhibits superior catalytic activity and selectivity relative to other as-obtained Co catalysts, because of the synergy effect of Co2+ sites to promote the adsorptive activation of CO group and small-size Co0 sites to facilitate the activating dissociation of hydrogen. Furthermore, the catalytic role of water has also been explored. Adopting water as pure solvent and partially adding water into organic solvent can both effectively enhance the activity and selectivity. Such reaction environment may induce creation of more intermolecular hydrogen bonds for promoting the hydrogen transfer and thus boosting the hydrogenation reaction.

Unravelling the synergy of platinum-oxygen vacancy in CoOx for modulating hydrogenation performance

Constructing high-efficiency catalysts with high activity and selectivity is the long-term pursuit in heterogeneous catalysis field. Metal–oxygen vacancy (Ov) synergy provides a promising route to realizing the goal. In this study, the Pt/CoOx catalysts with Pt–Ov dual sites are designed by atomic layer deposition (ALD) for selective hydrogenation of cinnamaldehyde, and the Ov property, Pt size and the spatial relationship of Pt and CoOx can be well modulated. Experimental and theoretical investigations indicate that the substrate and hydrogen can be activated on Ov and Pt nanoparticles, respectively. The Ov introduced by ALD not only preferentially activates CO bond of CALD to achieve high selectivity to CALA, but also enhances the ability to dissociate hydrogen on Pt nanoparticles through Pt-Ov electron transfer. Importantly, the optimized Pt40/CoOx-Ov catalysts with suitable Ov coordination and Pt sizes (2.5 nm) show lower adsorption energy for reactant molecules, obtaining significantly enhanced activity with a turnover frequency value of 202.5 molCALD·molPt-1·min−1 and obviously improved selectivity of desired products (93 %). This work offers a fundamental understanding of Pt–Ov synergy toward hydrogenation of unsaturated compounds.