Electrochemical Synthesis Of Hydrogen Peroxide Research Articles

Highly efficient hydrogen peroxide electrosynthesis on oxidized carbon nanotubes by thermally activated-persulfate

Electrochemical synthesis of hydrogen peroxide (H2O2) through two-electron oxygen reduction represents an attractive alternative for on-site H2O2 generation. Here, we develop a facile thermally activated-persulfate approach to obtain oxidized carbon nanotubes (O-CNTs-x, x represents oxidation time) with enhanced H2O2 electrosynthesis performance. Electrochemical studies have demonstrated that the optimized O-CNTs-6 (i.e., oxidation time is 6 h) could deliver a sustained high selectivity of around 92% for H2O2 over a wide voltage window in 0.1 mol/L KOH and a high H2O2 production rate of 296.84 mmol/L g-1cat h-1. Compared with pristine CNTs, the enhanced catalytic activity primarily stems from the newly-generated oxygen-containing functional groups and some defects created on the surface of O-CNTs-x. Importantly, the proposed oxidation process is proved to be valid for promoting H2O2 electrosynthesis performance of the Ketjen black. This study provides an universal oxidation method to obtain highly active carbon-based catalysts and initiates new opportunities for the exploration of high-performance electrosynthesis H2O2 catalysts.

Wet-Spun PEDOT/CNT Composite Hollow Fibers as Flexible Electrodes for H2O2 Production.

The electrochemical synthesis of hydrogen peroxide (H2O2) using the oxygen reduction reaction (ORR) requires highly catalytic active, selective, and stable electrode materials to realize a green and efficient process. The present publication shows for the first time the application of a facile one‐step bottom‐up wet‐spinning approach for the continuous fabrication of stable and flexible tubular poly(3,4‐ethylene dioxythiophene) (PEDOT : PSS) and PEDOT : PSS/carbon nanotube (CNT) hollow fibers. Additionally, electrochemical experiments reveal the catalytic activity of acid‐treated PEDOT : PSS and its composites in the ORR forming hydrogen peroxide for the first time. Under optimized conditions, the composite electrodes with 40 wt % CNT loading could achieve a high production rate of 0.01 mg/min/cm2 and a current efficiency of up to 54 %. In addition to the high production rate, the composite hollow fiber has proven its long‐term stability with 95 % current retention after 20 h of hydrogen peroxide production.

High-performance single-atom Ni catalyst loaded graphyne for H2O2 green synthesis in aqueous media

The electrochemical synthesis of hydrogen peroxide (H2O2) provides a greener and more efficient method compared with classic catalysts containing toxic metals. Herein, we used first-principles density functional theory (DFT) calculations to investigate 174 different single-atom catalysts with graphyne substrates, and conducted a three-step screening strategy to identify the optimal noble metal-free single atom catalyst. It is found that a single Ni atom loaded on γ-graphyne with carbon vacancies (Ni@V-γ-GY) displayed remarkable thermodynamic stability, excellent selectivity, and high activity with an ultralow overpotential of 0.03 V. Furthermore, based on ab-initio molecular dynamic and DFT calculations under the H2O solvent, it was revealed that the catalytic performance for H2O2 synthesis in aqueous phase was much better than that in gas phase condition, shedding light on the hydrogen bond network being beneficial to accelerate the transfer of protons for H2O2 synthesis.

Modeling and Multi-Criteria Optimization of a Process for H2O2 Electrosynthesis

This article introduces a novel laboratory-scale process for the electrochemical synthesis of hydrogen peroxide (H2O2). The process aims at an energy-efficient, decentralized production, and a mathematical optimization of it is presented. A dynamic, zero-dimensional mathematical model of the reactor is set up in Aspen custom modeler®. The proposed model constitutes a reasonable compromise between complexity and convergence. After thoroughly determining the reaction kinetics by adjustment to experimental data, the reactor unit is embedded in an Aspen Plus® flowsheet in order to investigate its interaction with other unit operations. The downstream contains another custom module for membrane distillation. Electricity appears as a resource in the process, and optimization shows that it reaches product purities of up to 3 wt.-%. Both the process optimization and the adjustment of the reaction kinetics are treated as multi-criteria optimization (MCO) problems.

Plasma activation towards oxidized nanocarbons for efficient electrochemical synthesis of hydrogen peroxide

Oxidized nanocarbons (ONCs) have been regarded as efficient electrocatalysts for H2O2 production. However, wet chemical procedures involving large volumes of strong acid and long synthetic time are usually needed to obtain these ONCs. Herein, a plasma activation strategy is developed as a rapid and environmentally benign approach to obtain various ONCs, including oxidized multiwalled carbon nanotubes, single-walled carbon nanotube, graphene, and super P carbon black. After a few minutes of plasma activation, oxygen-containing functional groups and defects can be effectively introduced onto the surface of nanocarbons. Enhanced electrocatalytic activity and selectivity are demonstrated by the plasma-ONCs for H2O2 production. Taking oxidized multiwalled carbon nanotubes as an example, high selectivity (up to 95%) and activity (0.75 V at 1 mA cm−2) can be achieved in alkaline solution. Moreover, ex situ x-ray photoelectron spectroscopy and in situ Raman measurements reveal that C–O, C=O, edge defect, and sp2 basal planar defect are probably the active sites.

Building highly active hybrid double–atom sites in C2N for enhanced electrocatalytic hydrogen peroxide synthesis

Two–electron (2e-) oxygen reduction reaction (ORR) shows great promise for on–site electrochemical synthesis of hydrogen peroxide (H2O2). However, it is still a great challenge to design efficient electrocatalysts for H2O2 synthesis. To address this issue, the logical design of the active site by controlling the geometric and electronic structures is urgently desired. Therefore, using density functional theory (DFT) computations, two kinds of hybrid double–atom supported on C2N nanosheet (RuCu@C2N and PdCu@C2N) are screened out and their H2O2 performances are predicted. PdCu@C2N exhibits higher activity for H2O2 synthesis with a lower overpotential of 0.12 V than RuCu@C2N (0.59 V), Ru3Cu(110) facet (0.60 V), and PdCu(110) facet (0.54 V). In aqueous phase, the adsorbed O2 is further stabilized with bulk H2O and the thermodynamic rate–determining step of 2e- ORR change. The activation barrier on PdCu@C2N is 0.43 eV lower than the one on RuCu@C2N with 0.68 eV. PdCu@C2N is near the top of 2e- ORR volcano plot, and exhibits high selectivity of H2O2. This work provides guidelines for designing highly effective hybrid double–atom electrocatalysts (HDACs) for H2O2 synthesis.

Progress of Electrochemical Hydrogen Peroxide Synthesis over Single Atom Catalysts

The electrochemical oxygen reduction reaction (ORR) via the two-electron pathway provides a promising approach for the direct synthesis of hydrogen peroxide (H2O2) and its on-site utilizations. The...

Partially Pyrolyzed Binary Metal-Organic Framework Nanosheets for Efficient Electrochemical Hydrogen Peroxide Synthesis.

Herein, we developed a partially controlled pyrolysis strategy to create evenly distributed NiO nanoparticles within NiFe-MOF nanosheets (MOF NSs) for electrochemical synthesis of H2 O2 by a two-electron oxygen reduction reaction (ORR). The elemental Ni can be partially transformed to NiO and uniformly distributed on the surface of the MOF NSs, which is crucial for the formation of the particular structure. The optimized MOF NSs-300 exhibits the highest activity for ORR with near-zero overpotential and excellent H2 O2 selectivity (ca. 99 %) in 0.1 m KOH solution. A high-yield H2 O2 production rate of 6.5 mol gcat -1 h-1 has also been achieved by MOF NSs-300 in 0.1 m KOH and at 0.6 V (vs. RHE). In contrast to completely pyrolyzed products, the enhanced catalytic activities of partially pyrolyzed MOF NSs-300 originates mainly from the retained MOF structure and the newly generated NiO nanoparticles, forming the coordinatively unsaturated Ni atoms and tuning the performance towards electrochemical H2 O2 synthesis.

Partially Pyrolyzed Binary Metal–Organic Framework Nanosheets for Efficient Electrochemical Hydrogen Peroxide Synthesis

AbstractHerein, we developed a partially controlled pyrolysis strategy to create evenly distributed NiO nanoparticles within NiFe‐MOF nanosheets (MOF NSs) for electrochemical synthesis of H2O2 by a two‐electron oxygen reduction reaction (ORR). The elemental Ni can be partially transformed to NiO and uniformly distributed on the surface of the MOF NSs, which is crucial for the formation of the particular structure. The optimized MOF NSs‐300 exhibits the highest activity for ORR with near‐zero overpotential and excellent H2O2 selectivity (ca. 99 %) in 0.1 m KOH solution. A high‐yield H2O2 production rate of 6.5 mol gcat−1 h−1 has also been achieved by MOF NSs‐300 in 0.1 m KOH and at 0.6 V (vs. RHE). In contrast to completely pyrolyzed products, the enhanced catalytic activities of partially pyrolyzed MOF NSs‐300 originates mainly from the retained MOF structure and the newly generated NiO nanoparticles, forming the coordinatively unsaturated Ni atoms and tuning the performance towards electrochemical H2O2 synthesis.

Defect engineering of single-walled carbon nanohorns for stable electrochemical synthesis of hydrogen peroxide with high selectivity in neutral electrolytes

Defect engineering of single-walled carbon nanohorns for stable electrochemical synthesis of hydrogen peroxide with high selectivity in neutral electrolytes

A Review on Challenges and Successes in Atomic-Scale Design of Catalysts for Electrochemical Synthesis of Hydrogen Peroxide

Hydrogen peroxide is a valuable chemical oxidant with a wide range of applications in a variety of industrial processes, especially in water sanitization. Electrochemical synthesis of hydrogen pero...

Atom-Coordinated Structure Triggers Selective H2O2 Production

The family of atomic catalysts in defective carbons is now of increasing interest for diverse reactions. In this issue of Chem, Liu and co-workers unveil the nature of M–N–C (M = Mn, Fe, Co, Ni, and Cu) as active sites that can finely tune the oxygen reduction reaction (ORR) pathways spanning 1e–4e transfer processes.

Electrocatalytic oxygen reduction to hydrogen peroxide by oxidized graphene aerogel supported cubic MnCO3 for antibacteria in neutral media

The electrochemical synthesis of hydrogen peroxide (H2O2) based on 2-electron oxygen reduction reaction (ORR), is a particularly promising alternative route for in-situ application. Herein, we prepared the oxidized graphene aerogel supported cubic manganese carbonate composites (GOx/MnCO3) with different GO and MnCO3 ratio through a simple co-precipitation/in-situ coating method. The GOx/MnCO3 composites, with uniformly wrapping of GO on the surface of MnCO3 cubic, display high conductivity and abundant catalytic sites for 2-electron ORR. The G0.2M shows the best ORR catalytic performance, onset potential of 0.635 VRHE, high H2O2 production selectivity and high stability in 3.5% NaCl electrolyte. Based on this, G0.2M as oxygen reduction electrocatalyst, has good antibacterial effect at 0.55 VRHE on the stainless-steel. The antibacterial mechanism is mainly due to the electrocatalytic oxygen reaction of H2O2 and the side reaction of •OH and O2•-. This provides an impressive, effective and environmentally friendly electrochemical approach for antibacterial and antifouling applications.

Cathodic Hydrogen Peroxide Electrosynthesis Using Anthraquinone Modified Carbon Nitride on Gas Diffusion Electrode

Electrochemical synthesis of hydrogen peroxide from oxygen and water can be a cost-effective and energy-efficient alternative to the traditional approach which requires high energy input and expens...

Electrochemical synthesis of hydrogen peroxide from water and oxygen

H2O2 is important in large-scale industrial processes and smaller on-site activities. The present industrial route to H2O2 involves hydrogenation of an anthraquinone and O2 oxidation of the resulting dihydroanthraquinone — a costly method and one that is impractical for routine on-site use. Electrosynthesis of H2O2 is cost-effective and applicable on both large and small scales. This Review describes methods to design and assess electrode materials for H2O2 electrosynthesis. H2O2 can be prepared by oxidizing H2O at efficient anodic catalysts such as those based on BiVO4. Alternatively, H2O2 forms by partially reducing O2 at cathodes featuring either noble metal alloys or doped carbon. In addition to the catalyst materials used, one must also consider the form and geometry of the electrodes and the type of reactor in order to strike a balance between properties such as mass transport and electroactive area, both of which substantially affect both the selectivity and rate of reaction. Research into catalyst materials and reactor designs is arguably quite mature, such that the future of H2O2 electrosynthesis will instead depend on the design of complete and efficient electrosynthesis systems, in which the complementary properties of the catalysts and the reactor lead to optimal selectivity and overall yield. Electrosynthesis is a practical and green route to hydrogen peroxide, and could reduce our dependence on less environmentally friendly oxidants. This Review describes catalyst and reactor designs for highly selective hydrogen peroxide electrosynthesis.

Selective H2O2 production on surface-oxidized metal-nitrogen-carbon electrocatalysts

The electrochemical synthesis of hydrogen peroxide (H2O2) can provide an attractive alternative to the current anthraquinone redox process, as it combines on-site chemical and electricity productions. A major challenge in the electrochemical H2O2 synthesis is the catalyst design which leads to a selective two-electron pathway in the oxygen reduction reaction (ORR) without dissociation of the OO bond. In the present work, we report that the partial oxidation of metal-nitrogen-carbon catalysts (Me-N-C, Me = iron, cobalt and manganese) can modify their ORR mechanisms from a four- to a two-electron pathway. Spectroscopic measurements reveal that ex situ H2O2 treatment introduces abundant oxygen functionalities on the Me-N-C surface without considerable changes to their bulk properties, such as crystallinity, degree of defects, surface area, and metal contents. Decreased H2O2 reduction kinetics on the oxidized catalysts confirm that the dissociation of the OO bond is strongly suppressed by the newly introduced oxygen functionalities. Among the three central metal candidates, the cobalt-nitrogen-carbon catalyst shows the highest H2O2 selectivity of >85%. This work provides a new simple guideline for designing Me-N-C catalysts for the efficient electrochemical synthesis of H2O2.

ZnO As an Active and Selective Catalyst for Electrochemical Water Oxidation to Hydrogen Peroxide

Electrochemical synthesis of hydrogen peroxide (H2O2) via two-electron water oxidation reaction (2e-WOR) is an ideal process for delocalized production for water cleaning and other applications. Pr...

Understanding the high activity of mildly reduced graphene oxide electrocatalysts in oxygen reduction to hydrogen peroxide

The direct electrochemical synthesis of hydrogen peroxide (H2O2) would provide an attractive alternative to the traditional anthraquinone oxidation process for continuous on-site applications.

CaSnO3: An Electrocatalyst for Two-Electron Water Oxidation Reaction to Form H2O2

The two-electron water oxidation reaction (2e-WOR) is a promising route for distributed electrochemical synthesis of hydrogen peroxide (H2O2), an effective and green oxidizer, bleaching agent, and antiseptic. To date, the best electrocatalyst for 2e-WOR, in terms of selectivity against the competing 4e-WOR to form O2, is BiVO4. Nevertheless, BiVO4 is unstable and has a high overpotential of ∼340 mV at 0.2 mA/cm2 for 2e-WOR. Herein, we use density functional theory to identify a new, efficient, selective, and stable electrocatalyst for 2e-WOR, i.e., the ternary oxide calcium stannate (CaSnO3). Our experiments show that CaSnO3 achieves an overpotential of 230 mV at 0.2 mA/cm2, peak Faraday efficiency of 76% for 2e-WOR at 3.2 V vs the reversible hydrogen electrode (RHE), and stable performance for over 12 h, outperforming BiVO4 in all aspects. This work demonstrates the promise of CaSnO3 as a selective and cost-effective electrocatalyst candidate for H2O2 production from water oxidation.

Designing Boron Nitride Islands in Carbon Materials for Efficient Electrochemical Synthesis of Hydrogen Peroxide.

Heteroatom-doped carbons have drawn increasing research interest as catalysts for various electrochemical reactions due to their unique electronic and surface structures. In particular, co-doping of carbon with boron and nitrogen has been shown to provide significant catalytic activity for oxygen reduction reaction (ORR). However, limited experimental work has been done to systematically study these materials, and much remains to be understood about the nature of the active site(s), particularly with regards to the factors underlying the activity enhancements of these boron-carbon-nitrogen (BCN) materials. Herein, we prepare several BCN materials experimentally with a facile and controlled synthesis method, and systematically study their electrochemical performance. We demonstrate the existence of h-BN domains embedded in the graphitic structures of these materials using X-ray spectroscopy. These synthesized structures yield higher activity and selectivity toward the 2e- ORR to H2O2 than structures with individual B or N doping. We further employ density functional theory calculations to understand the role of a variety of h-BN domains within the carbon lattice for the ORR and find that the interface between h-BN domains and graphene exhibits unique catalytic behavior that can preferentially drive the production of H2O2. To the best of our knowledge, this is the first example of h-BN domains in carbon identified as a novel system for the electrochemical production of H2O2.