Enhanced Selective Oxidation of Benzyl Alcohol via In Situ H₂O₂ Production over Supported Pd-Based Catalysts

Abstract

Bimetallic Pd-Fe catalysts supported on TiO 2 are shown to be highly effective toward the selective oxidation of benzyl alcohol to benzaldehyde via the in situ production of H 2 O 2 from molecular H 2 and O 2 , under conditions where no reaction is observed with molecular O 2 alone. The rate of benzyl alcohol oxidation observed over supported Pd-Fe nanoparticles is significantly higher than those of either Pd-Au or Pd-only analogues. This enhanced activity can be attributed to the bifunctionality of the Pd-Fe catalyst to both synthesize H 2 O 2 and catalyze the production of oxygen-based radical specie,s as indicated by an electron paramagnetic resonance analysis. Further studies also reveal the noninnocent nature of the solvent, resulting in the propagation of radical generation pathways.

The degradation of phenol via in situ H2O2 production over supported Pd-based catalysts

“…29 In keeping with numerous studies, [32][33][34] . This is in keeping with our previous studies 24,36 and may be ascribed to a combination of (i) the reaction conditions chosen to…”

The Direct Synthesis of Hydrogen Peroxide Over Supported Pd-Based Catalysts: An Investigation into the Role of the Support and Secondary Metal Modifiers

“…Alternatively, the direct synthesis of H 2 O 2 from molecular H 2 and O 2 has the potential to avoid many of the drawbacks associated with the anthraquinone oxidation process, allowing for the on-site manufacture of dilute streams of H 2 O 2 [5]. Additionally, the in-situ production of H 2 O 2 has been demonstrated to offer improved activity, compared to the use of preformed H 2 O 2 , in a range of selective chemical transformations, under reaction conditions where H 2 O 2 is considered highly unstable [6][7][8][9][10]. With the enhanced performance of the in-situ approach possibly related to the avoidance of the acid stabilisers that are used to inhibit preformed H 2 O 2 decomposition during transport and storage.…”

Transforming Waste Clamshell into Highly Selective Nanostructured Catalysts for Solvent Free Liquid Phase Oxidation of Benzyl Alcohol

“…Several research efforts on benzyl alcohol oxidation studies have revealed important factors affecting reaction activity such as type and catalyst loading, H 2 O 2 : benzyl alcohol molar ratio, reaction duration and temperature [2,13,[30][31][32]. To achieve optimum performance, these key effective factors were investigated in detail as follows.…”

“…Reaction duration is one of the most effective reaction factors, which play an important role in the oxidation of benzyl alcohol [4,13,31,34]. Table 3 shows the conversion and selectivity values of the reaction at 5, 6, 7 and 8 h. Prolonged reaction duration increases the conversion percentage from 74 to 89% but decreases the selectivity from 92 to 85%, respectively.…”

“…A topic of new interest in this context is the design of environmentally friendly, recyclable, active and extremely selective heterogeneous nanocatalysts. In a comparative study, Pd nanoparticles appear as a new category of useful catalysts for the oxidation of benzyl alcohol with several benefits [13][14][15][16][17]. Unfortunately, high costs usually limit the large-scale use of noble metal-based catalysts such as Pd [16,17].…”