Direct synthesis of hydrogen peroxide from hydrogen and oxygen over palladium catalyst supported on heteropolyacid-containing ordered mesoporous carbon

Lee, Jong Won; Kim, Jeong Kwon; Kang, Tae Hun; Lee, Eo Jin; Song, In Kyu

doi:10.1016/j.cattod.2016.10.008

Cited by 20 publications

(10 citation statements)

References 23 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A series of Pd catalysts supported on ordered mesoporous carbons [97] were prepared by surfactant templating and incipient wetness impregnation of ordered mesoporous carbons that were previously synthesized at different temperatures (T = 8, 15, 25, 35, and 45 • C). Conversion of hydrogen and hydrogen peroxide yield showed volcano-shaped behaviors as a function of the preparation temperature when halide and acid additives were present ( Figure 5).…”

Section: Effect Of Supportsmentioning

confidence: 99%

Looking for the “Dream Catalyst” for Hydrogen Peroxide Production from Hydrogen and Oxygen

et al. 2019

View full text Add to dashboard Cite

The reaction between hydrogen and oxygen is in principle the simplest method to form hydrogen peroxide, but it is still a “dream process”, thus needing a “dream catalyst”. The aim of this review is to analyze critically the different heterogeneous catalysts used for the direct synthesis of H2O2 trying to determine the features that the ideal or “dream catalyst” should possess. This analysis will refer specifically to the following points: (i) the choice of the metal; (ii) the metal promoters used to improve the activity and/or the selectivity; (iii) the role of different supports and their acidic properties; (iv) the addition of halide promoters to inhibit undesired side reactions; (v) the addition of other promoters; (vi) the effects of particle morphology; and (vii) the effects of different synthetic methods on catalyst morphology and performance.

show abstract

Section: Effect Of Supportsmentioning

confidence: 99%

Looking for the “Dream Catalyst” for Hydrogen Peroxide Production from Hydrogen and Oxygen

et al. 2019

View full text Add to dashboard Cite

show abstract

“…On the other hand, Schlögl et al found that sintering of Pd nanoparticles is responsible for total hydrogenation to water and needs to be prevented to maintain high selectivity [16]. In order to incorporate the acidic function in the catalyst Pd supported on ordered mesoporous carbon doped with heteropolyacids (HPA) was recently studied by Lee et al who found increasing selectivity and productivity with increasing HPA content/acidity [17]. Similarly, Blanco-Brieva et al reported that catalytic performance increases with acidity of the support with Pd supported on silica functionalized with aryl sulfonic, alkyl phosphonic and alkyl carboxylic groups [18].…”

Section: Toc Graphics: Introductionmentioning

confidence: 99%

Revealing the Structure and Mechanism of Palladium during Direct Synthesis of Hydrogen Peroxide in Continuous Flow Using Operando Spectroscopy

Selinsek¹,

Deschner²,

Doronkin

et al. 2018

ACS Catal.

113

View full text Add to dashboard Cite

The direct synthesis of H2O2 is a dream reaction in the field of selective oxidation and green chemical synthesis. However, the unknown active state of the catalyst and the lack of a defined catalytic mechanism preclude the design and optimization of suitable catalysts and reactor setups. Here direct synthesis of H2O2 over Pd-TiO2 in water was investigated in a continuous flow reactor setup utilizing undiluted oxygen and hydrogen to increase aqueous phase concentrations safely at ambient temperature and a pressure of 10 bars. In this experiment operando X-ray Absorption Spectroscopy (XAS) and online flow injection analysis for photometric quantification of H2O2 were combined to build catalyst structure-activity relationships in direct H2O2 synthesis. XAS at the Pd K absorption edge was used to observe oxidation state and local Pd structure together with H2O2 production for three reactant ratio (H2/O2) regimes: hydrogen rich (> 2), hydrogen lean (< 0.5) and balanced (0.5-2). During H2O2 production, oxygen was only found adsorbed on the surface of Pd nanoparticles and hydrogen was found dissolved in bulk palladium hydride (α-phase) indicating a reaction of surface oxygen with lattice hydrogen to form hydrogen peroxide. Under hydrogen rich conditions, formation of β-phase palladium hydride was found to coincide with zero H2O2 yield. This constitutes an operando study of direct H2O2 synthesis under elevated partial pressures of H2 and O2 in continuous flow. The results obtained will aid in rational design of future catalysts and optimization of process parameters, bringing the concept of a viable, efficient process for H2O2 synthesis one step closer to reality.

show abstract

“…The passivation procedure was applied and the setup was thoroughly cleaned once it had been found that catalyst traces were present after the coating experiments (Table 1, Exp.-Nr. : [29][30][31][32][33][34][35][36][37]. Experiments affected by catalyst traces are obviously not shown in this work and are neither part of the experimental discussion.…”

Section: Methodsmentioning

confidence: 81%

“…The salts of sulfuric-and phosphoric acid certainly had a beneficial effect similar to NaBr. Furthermore, it is common belief that H + has a positive effect in the formation of H 2 O 2 [39] which, e.g., also motivated research on solid acids as catalyst supports to enhance selectivity [32,33]. To study the influence on our system, a set of experiments have been performed by controlling the pH value in the solvent via a sodium acetate buffer at pH 3 and comparing it to a solution with 5 mM H 3 PO 4 and 25 mM H 2 SO 4 to study the influence of H + (Exp.-Nr.…”

Section: Influence Of Additivesmentioning

confidence: 99%

“…Furthermore, Pd nanoparticles with a diameter of 1.4 nm achieved the best catalytic performance while single site Pd nanoparticles were inactive, further indicating an important interaction between surface and subsurface domains [31]. Lee et al recently studied catalysts using Pd supported on ordered mesoporous carbon doped with heteropolyacids (HPA) and found increasing selectivity and productivity with increasing HPA content/acidity [32]. Similarly, another group reported that catalytic performance increases with acidity of the support with Pd supported on silica functionalized with aryl sulfonic, alkyl phosphonic and alkyl carboxylic groups [33].…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Experimental Evaluation of a Membrane Micro Channel Reactor for Liquid Phase Direct Synthesis of Hydrogen Peroxide in Continuous Flow Using Nafion® Membranes for Safe Utilization of Undiluted Reactants

2018

View full text Add to dashboard Cite

In recent years, various modular micro channel reactors have been developed to overcome limitations in challenging chemical reactions. Direct synthesis of hydrogen peroxide from hydrogen and oxygen is a very interesting process in this regard. However, the complex triphasic process (gaseous reactants, reaction in liquid solvent, solid catalyst) still holds challenges regarding safety, selectivity and productivity. The membrane micro reactor system for continuous liquid phase H2O2 direct synthesis was designed to reduce safety issues by separate dosing of the gaseous reactants via a membrane into a liquid-flow channel filled with a catalyst. Productivity is increased by enhanced mass transport, attainable in micro channels and by multiple re-saturation of the liquid with the reactants over the length of the reaction channel. Lastly, selectivity is optimized by controlling the reactant distribution. The influence of crucial technical features of the design, such as micro channel geometry, were studied experimentally in relationship with varying reaction conditions such as residence time, pressure, reactant ratio and solvent flow rate. Successful continuous operation of the reactor at pressures up to 50 bars showed the feasibility of this system. During the experiments, control over the reactant ratio was found to be crucial in order to maximize product yield. Thereby, yields above 80% were achieved. The results obtained are the key elements for future development and optimization of this reactor system, which will hopefully lead to a breakthrough in decentralized H2O2 production.

show abstract

Direct synthesis of hydrogen peroxide from hydrogen and oxygen over palladium catalyst supported on heteropolyacid-containing ordered mesoporous carbon

Cited by 20 publications

References 23 publications

Looking for the “Dream Catalyst” for Hydrogen Peroxide Production from Hydrogen and Oxygen

Looking for the “Dream Catalyst” for Hydrogen Peroxide Production from Hydrogen and Oxygen

Revealing the Structure and Mechanism of Palladium during Direct Synthesis of Hydrogen Peroxide in Continuous Flow Using Operando Spectroscopy

Experimental Evaluation of a Membrane Micro Channel Reactor for Liquid Phase Direct Synthesis of Hydrogen Peroxide in Continuous Flow Using Nafion® Membranes for Safe Utilization of Undiluted Reactants

Contact Info

Product

Resources

About