Influence of Metal Precursors and Reduction Protocols on the Chloride‐Free Preparation of Catalysts for the Direct Synthesis of Hydrogen Peroxide without Selectivity Enhancers

Abstract

Different metal precursors and reducing agents were applied in the preparation of 1 wt % Pd catalysts supported on commercial ion‐exchange resin (Lewatit K2621) and used in the direct synthesis of H2O2. The catalysts were characterized by using TEM and their performance was evaluated in the direct synthesis of H2O2 (in a batch and semi‐batch reactor) to investigate the relationship between the catalyst preparation methods, morphology, and catalytic performance. As expected, both the choice of the Pd precursor and the reduction conditions had a strong influence on the size and size distribution of the resulting supported nanostructured metal nanoparticles and, consequently, on the catalytic performance. The best combination of metal precursor and reduction agent was [Pd(NH3)4]SO4 reduced with hydrogen. This catalyst had the largest average size of the Pd nanoparticles and the broadest size distribution.

Comparing Catalysts of the Direct Synthesis of Hydrogen Peroxide in Organic Solvent: is the Measure of the Product an Issue?

“…For this paper we have reviewed 79 papers dealing with the DS and published since 2000 to date [8–80] (Figure 1). Out of them three regrettably did not report how the amount of H 2 O 2 was measured [81–83] .…”

Solar‐Driven Production of Hydrogen Peroxide from Water and Dioxygen

“…[60][61][62] Thus, extensive efforts have been devoted to achieve direct synthesis of H 2 O 2 from H 2 and O 2 using variousc atalysts, enabling efficient and on-site H 2 O 2 production, which not only significantly reduces the cost for H 2 O 2 synthesis, transport, storage, and handling, but also facilitates the subsequento xidationr eactions. [60][61][62][63][64][65][66][67][68][69][70] However,agas mixture of H 2 andO 2 has potentiale xplosion risk. It is highly desired to produce H 2 O 2 from H 2 Oa nd O 2 without using H 2 .…”

“…However, this multi‐step method is hazardous, energy‐intensive and difficult for in situ H 2 O 2 production . Thus, extensive efforts have been devoted to achieve direct synthesis of H 2 O 2 from H 2 and O 2 using various catalysts, enabling efficient and on‐site H 2 O 2 production, which not only significantly reduces the cost for H 2 O 2 synthesis, transport, storage, and handling, but also facilitates the subsequent oxidation reactions . However, a gas mixture of H 2 and O 2 has potential explosion risk.…”

Direct Synthesis of Hydrogen Peroxide under Semi-Batch Conditions over Un-Promoted Palladium Catalysts Supported by Ion-Exchange Sulfonated Resins: Effects of the Support Morphology

“…Shortly after one of us co-authored a report [29] describing the DS promoted by palladium and palladium-gold catalysts supported by Lewatit K2621 (a S-pSDVB resin similar to K2641) [30] and an acrylic resins, either sulfonated or functionalized with alkylsulfide groups [29]. Since then our group contributed to a number of other papers illustrating the performance of palladium, palladium-platinum and palladium-gold catalysts in the DS with and without halide ions as promoters [31][32][33][34][35][36][37]. Among crosslinked resins "solvothermal" poly-divinylbenzene [38] recently emerged as the first representative of a new class of porous polymers, including also acrylic resins [39].…”