Bimetallic Catalysts Containing Gold and Palladium for Environmentally Important Reactions

Abstract

Supported bimetallic nanoparticles (SBN) are extensively used as efficient redox catalysts. This kind of catalysis particularly using SBN has attracted immense research interest compared to their parent metals due to their unique physico-chemical properties. The primary objective of this contribution is to provide comprehensive overview about SBN and their application as promising catalysts. The present review contains four sections in total. Section 1 starts with a general introduction, recent progress, and brief summary of the application of SBN as promising catalysts for different applications. Section 2 reviews the preparation and characterization methods of SBN for a wide range of catalytic reactions. Section 3 concentrates on our own results related to the application of SBN in heterogeneous catalysis. In this section, the oxidation of cyclohexane to adipic acid (an eco-friendly and novel approach) will be discussed. In addition, the application of bimetallic Pd catalysts for vapor phase toluene acetoxylation in a fixed bed reactor will also be highlighted. Acetoxylation of toluene to benzyl acetate is another green route to synthesize benzyl acetate in one step. Finally, Section 1 describes the summary of the main points and also presents an outlook on the application of SBN as promising catalysts for the production of valuable products.

Upgrading Lignocellulosic Biomasses: Hydrogenolysis of Platform Derived Molecules Promoted by Heterogeneous Pd-Fe Catalysts

“…Preparation methods for the development of efficient bimetallic Pd-Fe catalysts were focused, in addition to the fundamental properties (activity, selectivity and stability) and practical applications (reuse, reproducibility and easy separation from the reaction mixture), on the optimization of metal-metal or metal/support interactions [116][117][118][119][120][121][122][123][124][125]190]. …”

Heterogeneous Gold Catalysis: From Discovery to Applications

“…As discussed in the previous section, the catalytic activity of supported AuNPs catalysts is extremely dependent on the size of AuNPs. The preparation of supported AuNPs catalysts is certainly considered as a strategic aspect strongly affecting the size of AuNPs [32][33][34]. Among the various methods for the preparation of Au catalysts, the impregnation approach finds particularly frequent applications.…”

“…Furthermore, in CO oxidation and the epoxidation of propylene applying supported AuNPs, the size of AuNPs should be below 5 nm in order to enhance the catalytic activity and avoid any byproducts [84]. Various research groups claimed the particle size to be a determining factor in the performance of a catalyst [32]. Furthermore, the catalytic trend of multi-elements supported catalysts is known to extremely rely on the size of the metal particles and on their common interactions [85].…”

Dynamic Processes on Gold-Based Catalysts Followed by Environmental Microscopies

“…In addition to this, a decreased size of the particles increases the dispersion, and accordingly the number of edges and kinks on the metallic particles: such highly uncoordinated surface sites could correspond to the preferential adsorption sites, and their increasing number could then be responsible for the increasing reactivity of the catalytic materials. During the last decade, the research on catalytic materials with gold mainly focuses on the development of bimetallic gold-based catalysts [48][49][50][51][52]. Indeed, the use of bimetallic catalysts allows, to some extent, the size sensitivity of gold catalysts to be diminished.…”