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In this work, a convenient approach has been applied to discover the potential valorization of biomass waste such as orange peel in which PdCu-based nanostructured systems were synthesized via a one-step in-situ dry-milling approach to obtain the benign bimetallic catalysts with different palladium(Pd) and Copper(Cu) loadings on the orange peel support (Pd1%Cu1%, Pd0.3%Cu0.7%, Pd0.5%Cu0.5%, Pd0.5%Cu1%). Catalytic applications of these new composites were investigated in the Sonogashira-Hagihara coupling reaction as well as the Sonogashira–click reaction sequence to the preparation of substituted 4-aryl-1,2,3-triazoles and reduction of nitroaromatics under mild reaction conditions. Catalytic tests with the four activated carbons catalysts showed that the C@Pd1%Cu1% catalyst was the most active in the Sonogashira-Hagihara coupling reaction compared to the other catalysts. Also, the C@Pd0.5%Cu0.5% catalyst showed the highest catalytic activity in the reduction of 1-chloro-4-nitrobenzene and 4-nitrophenol in comparison with other prepared carbon catalysts.

Gold catalysts have been reported to be applied only for the Sonogashira-Hagihara reaction of iodobenzene and phenylacetylene under harsh reaction conditions, while the scope of the reaction has not been expanded for coupling reaction of other aryl halides and alkynes. In this investigation, a cost-effective, Pd-free catalyst based on mesoporous magnesium oxide supported bimetallic AuNi nanoparticles (m-MgO@AuNi) have been synthesized by hydrothermal method and its efficiency has been demonstrated in Sonogashira-Hagihara cross-coupling reaction. The m-MgO@AuNi nanocatalyst was structurally and morphologically characterized using X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), X-ray Photoelectron Spectroscopy (XPS) and the mesoporous structure of MgO has been confirmed through BET analysis. Using this palladium-free catalyst, Sonogashira-Hagihara coupling reaction of aryl iodides and aryl bromides with alkynes have been successfully performed and catalyst was recycled for several times. The results demonstrate that the synergistic effect between Au, Ni and mesoporous MgO support plays key role in enhancement of m-MgO@AuNi catalytic activity in Sonogashira-Hagihara reaction.

Bimetallic Fe–Cu MOF was effectively synthesized through a one-pot solvothermal process and successfully characterized by TEM, XPS, SEM, XRD, BET, EDX, elemental mapping, and FT-IR analysis. This bimetallic MOF was employed as a catalyst in the reduction of nitroarenes at room temperature and as well as in the reduction of dyes, for example, methyl orange (MO) and methylene blue (MB). Results pointed to Fe–Cu MOF exhibiting outstanding catalytic performance for both room temperature reactions. The catalytic activity of Fe–Cu MOF in comparison with Fe-MOF and Cu-MOF in the nitroarenes reduction indicated a superior activity compared with single-metal MOFs. Activity of Fe–Cu MOF catalyst did not change after its recycling and reusing for seven consecutive cycles in nitrobenzene reduction.

FeCu MOF has been prepared via solvothermal method and the resulting bimetallic MOF was employed for stabilization of Pd species. Obtained Pd(II)@NH2BDC-FeCu MOF could act as an effective environmental catalyst in Sonogashira-Hagihara coupling reaction and the reduction of organic dyes. This recyclable catalyst demonstrated high catalytic activity for Sonogashira reaction of aryl iodides and aryl bromides with alkynes. Rhodamine B and methyl red as organic dyes were instantly reduced. Pd(II)@NH2BDC-FeCu/MOF was characterized by TEM, XPS, FT-IR, BET, XRD, and SEM. In addition, the synthesized catalyst was recyclable and reusable for 6 sequential times without deteriorating remarkable in catalytic performance for reaction of iodobenzene with phenylacetylene.

A Palladium supported onto an ionic liquid-modified carbon nanotube is prepared. Scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), thermogravimetric analysis (TGA), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS) are used to complete its characterization. The application as catalyst in the copper-free Sonogashira-Hagihara coupling is also studied employing different substrates. This heterogeneous catalyst is successfully recycled for 5 consecutive identical reactions maintaining its efficiency. After this fifth catalytic run the catalyst is characterized again.

Bimetallic PdCu nanoparticles can be applied as catalysts in a wide range of chemical and electrochemical reactions. This review article overviews the preparation and synthetic applications of these bimetallic nanoparticles (BNPs) developed mainly over the last 20 years. These BNPs show better catalytic activity and selectivity than the monometallic counterparts due to their electronic and structural interactions. Simple general preparation methods include reduction of the corresponding salt precursors by different agents, solvothermal processes and galvanic replacement. In the case of supported catalysts, mainly wet impregnation and in situ reduction processes are used. In addition, these nanomaterials are prepared with different Pd/Cu compositions and with different morphologies. In the case of supported materials, many solid supports especially alumina, silica, titania, ceria, magnetite, zeolites, active carbon, graphene, carbon nanotubes, resins and polymers are employed allowing the recovery and reuse of the supported catalyst. In addition, the presence of copper reduces the economic cost of using palladium in industrial processes. Among several synthetic applications, C–C bond forming reactions such as Suzuki–Miyaura, Sonogashira–Hagihara, Heck–Mizoroki, Guerbet and A3-coupling are efficiently performed with PdCu BNPs. Reduction reactions under PdCu catalysis such as nitrate reduction for water purification, hydrodechlorination of organic pollutants, hydrogenation of CO2 and CO to methanol, semihydrogenation of alkynes to alkenes, and hydrogenation of C[double bond, length as m-dash]C double bonds, furfural to furfuryl alcohol, polyols, levulinic and succinic acids to lactones, styrene oxide to 2-phenylethanol and nitroaromatics to aromatic amines can be successfully performed. In the case of electrocatalytic reductions, oxygen reduction to water, CO2 reductions to CO, to alcohols, to hydrocarbons and to formate and hydrogen generation from water splitting can

The 1-butyl-3-methyl-2-(diphenylphosphino)imidazalolium hexafluorophosphate is prepared and used as a water-soluble ligand in the Suzuki-Miyaura reaction. This ligand and palladium chloride generates a new active catalyst for the Suzuki coupling reaction between aryl iodides or bromides with arylboronic acids in neat water. This catalyst can be recycled and reused for the coupling reaction of 4-bromobenzonitrile with phenylboronic acid for at least six runs with low decreasing in catalytic activity.