Selective hydrogenation of cinnamaldehyde over reduced graphene oxide supported Pt catalyst

Advances in Graphene/Inorganic Nanoparticle Composites for Catalytic Applications

Graphene-based nanocomposites with inorganic (metal and metal oxide) nanoparticles leads to materials with high catalytic activity for a variety of chemical transformations. Graphene and its derivatives such as graphene oxide, highly reduced graphene oxide, or nitrogen-doped graphene are excellent support materials due to their high surface area, their extended π-system, and variable functionalities for effective chemical interactions to fabricate nanocomposites. The ability to fine-tune the surface composition for desired functionalities enhances the versatility of graphene-based nanocomposites in catalysis. This review summarizes the preparation of graphene/inorganic NPs based nanocomposites and their use in catalytic applications. We discuss the large-scale synthesis of graphene-based nanomaterials. We have also highlighted the interfacial electronic communication between graphene/inorganic nanoparticles and other factors resulting in increased catalytic efficiencies.

Obtaining Active Polylactide (PLA) and Polyhydroxybutyrate (PHB) Blends Based Bionanocomposites Modified with Graphene Oxide and Supercritical Carbon Dioxide (scCO2)-Assisted Cinnamaldehyde: Effect on Thermal-Mechanical, Disintegration and Mass Transport Properties

Bionanocomposites based on Polylactide (PLA) and Polyhydroxybutyrate (PHB) blends were successfully obtained through a combined extrusion and impregnation process using supercritical CO₂ (scCO₂). Graphene oxide (GO) and cinnamaldehyde (Ci) were incorporated into the blends as nano-reinforcement and an active compound, respectively, separately, and simultaneously. From the results, cinnamaldehyde quantification values varied between 5.7% and 6.1% (w/w). When GO and Ci were incorporated, elongation percentage increased up to 16%, and, therefore, the mechanical properties were improved, with respect to neat PLA. The results indicated that the Ci diffusion through the blends and bionanocomposites was influenced by the nano-reinforcing incorporation. The disintegration capacity of the developed materials decreased with the incorporation of GO and PHB, up to 14 and 23 days of testing, respectively, without compromising the biodegradability characteristics of the final material.

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.

Pt–Carbon interaction-determined reaction pathway and selectivity for hydrogenation of 5-hydroxymethylfurfural over carbon supported Pt catalysts

In the hydrogenation of HMF, the main product was DHMF over all carbon supported Pt catalysts prepared by impregnation, and it changed to DMF over the Pt catalysts prepared via atomic layer deposition due to the relatively strong Pt–CNT interaction.

Fly-through synthesis of nanoparticles on textile and paper substrates

The fast and efficient synthesis of nanoparticles on flexible and lightweight substrates is increasingly critical for various medical and wearable applications. However, conventional high temperature (high-T) processes for nanoparticle synthesis are intrinsically incompatible with temperature-sensitive substrates, including textiles and paper (i.e. low-T substrates). In this work, we report a non-contact, 'fly-through' method to synthesize nanoparticles on low-T substrates by rapid radiative heating under short timescales. As a demonstration, textile substrates loaded with platinum (Pt) salt precursor are rapidly heated and quenched as they move across a 2000 K heating source at a continuous production speed of 0.5 cm s-1. The rapid radiative heating method induces the thermal decomposition of various precursor salts and nanoparticle formation, while the short duration ensures negligible change to the respective low-T substrate along with greatly improved production efficiency. The reported method can be generally applied to the synthesis of metal nanoparticles (e.g. gold and ruthenium) on various low-T substrates (e.g. paper). The non-contact and continuous 'fly-through' synthesis offers a robust and efficient way to synthesize supported nanoparticles on flexible and lightweight substrates. It is also promising for ultrafast and roll-to-roll manufacturing to enable viable applications.

Efficient Pt–FeOx/TiO2@SBA-15 catalysts for selective hydrogenation of cinnamaldehyde to cinnamyl alcohol

Pt–FeO_x/TiO₂@SBA-15 serves as an efficient and recyclable catalyst for liquid-phase selective hydrogenation of cinnamaldehyde to cinnamyl alcohol under mild conditions.

Effect of carbon nanosheets with different graphitization degrees as a support of noble metals on selective hydrogenation of cinnamaldehyde

Effect of carbon nanosheets with different graphitization degrees on the catalytic activity of Pt/CNS and Pd/CNS was investigated in selective hydrogenation of cinnamaldehyde.

Effect of Carbon Supported Pt Catalysts on Selective Hydrogenation of Cinnamaldehyde

Selective hydrogenation of cinnamaldehyde (CAL) to cinnamyl alcohol (COL) is of both fundamental and industrial interest. It is of great significance to evaluate the possible differences between different supports arising from metal dispersion and electronic effects, in terms of activity and selectivity. Herein, Pt catalysts on different carbon supports including carbon nanotubes (CNTs) and reduced graphene oxides (RGO) were developed by a simple wet impregnation method. The resultant catalysts were well characterized by XRD, Raman, N2physisorption, TEM, and XPS analysis. Applied in the hydrogenation of cinnamaldehyde, 3.5 wt% Pt/CNT shows much higher selectivity towards cinnamyl alcohol (62%) than 3.5 wt% Pt/RGO@SiO2(48%). The enhanced activity can be ascribed to the high graphitization degree of CNTs and high density of dispersed Pt electron cloud.

Environmentally benign selective hydrogenation of α,β-unsaturated aldehydes and reduction of aromatic nitro compounds using Cu based bimetallic nanoparticles supported on multiwalled carbon nanotubes and mesoporous carbon

The catalytic activity of these materials was investigated in the hydrogenation of α,β-unsaturated aldehydes and reduction of aromatic nitro compounds using different hydrogen sources.

The superior performance of a Pt catalyst supported on nanoporous SiC–C composites for liquid-phase selective hydrogenation of cinnamaldehyde

The Pt/SiC–C catalyst: active, selective (80% selectivity to unsaturated alcohol) and reusable for liquid-phase hydrogenation of cinnamaldehyde at room temperature.

Graphene-supported metal/metal oxide nanohybrids: synthesis and applications in heterogeneous catalysis

This minireview outlines recent advances in the design and catalytic applications of graphene-supported metal/metal oxide nanohybrids.

Correlated bifunctionality in heterogeneous catalysts: selective tethering of cinchonidine next to supported Pt nanoparticles

A strategy has been devised to add molecular functionality to heterogeneous catalysts in a spatially correlated fashion.

Selective hydrogenation of cinnamaldehyde on nickel nanoparticles supported on titania: role of catalyst preparation methods

Proposed mode of adsorption of cinnamaldehyde on Ni/TiO₂.

Self-supported composites of thin Pt–Sn crosslinked nanowires for the highly chemoselective hydrogenation of cinnamaldehyde under ambient conditions

PtSn/SnO₂crosslinked nanowires with forming Pt–Sn alloy were highly chemoselective for hydrogenation of cinnamaldehyde to cinnamyl alcohol in good recyclability and stability under ambient conditions.

Catalytic hydrogenation by noble-metal nanocrystals with well-defined facets: a review

A brief overview of the activity and selectivity of noble-metal nanocrystals with well-defined facets in the field of catalytic hydrogenation .

Fabricating roughened surfaces on halloysite nanotubes via alkali etching for deposition of high-efficiency Pt nanocatalysts

Roughened halloysite nanotubes (RHNTs) were fabricated by etching the wall of HNTs in a molten-salt system.

Selectivity in the catalytic hydrogenation of cinnamaldehyde promoted by Pt/SiO2 as a function of metal nanoparticle size

In the catalytic hydrogenation of cinnamaldehyde by platinum, selectivity is structure insensitive but total activity is associated with flat terraces.