Electrocatalytic Synthesis Of Hydrogen Peroxide Research Articles

Doped‐Sn Enhanced the Performance of BiOCl Nanosheet on Electrocatalytic Synthesis of Hydrogen Peroxide

AbstractThe hydrogen peroxide (H2O2) produced through electrochemical two‐electron oxygen reduction reaction (2e− ORR) is a promising green synthesis method and served as potential strategy to replace the energy‐intensive anthraquinone process. Nevertheless, the design of low‐cost and efficient electrocatalysts for 2e− ORR remains a formidable challenge. In this study, Sn‐BiOCl nanosheets electrocatalysts are prepared for expediting the 2e− ORR, achieving a high H2O2 selectivity of 92.9%, and the H2O2 yield of 10628 mg L−1 h−1 (0.1 mg cm−2) in a flow‐cell device. The in situ ATR‐SEIRAS results reveal that Sn‐BiOCl enhances the adsorption and activation of *OOH compared to BiOCl, resulting in higher activity and selectivity for 2e− ORR. Furthermore, this study investigates the potential for on‐site production and application of H2O2 using Sn‐BiOCl, which displays a 95% degradation removal of dyes (RhB, MB, and MO) within 20 min. This work not only have an insight into the critical roles of Bi and Sn atoms in enhancing the catalytic performance but also provides a thought to design efficient catalysts for production H2O2 via electrochemical 2e− ORR.

Constructing alkaline microenvironment on catalyst surface for enhanced electrocatalytic synthesis of hydrogen peroxide in a neutral electrolyte

The direct electrochemical synthesis of H2O2 via a two-electron oxygen reduction reaction (2e− ORR) offers a feasible alternative to the energy-intensive anthraquinone oxidation process. Compared to alkaline electrolytes, challenges remain in achieving high 2e− ORR selectivity and activity for electrosynthesis of H2O2 in neutral electrolytes due to the low concentration of OH−, which hinders the effective binding of key intermediate OOH*. Here, we introduced Lewis acid TiO2 to modify carbon black catalyst for adsorbing in-situ generated OH− and created a local alkaline microenvironment for enhancing the 2e− ORR activity and selectivity in neutral electrolytes. H2O2 productivity of TiO2 modified carbon black catalyst (52.5 mmol L−1 h−1) in a neutral electrolyte (0.5 M Na2SO4) at 0.2 V vs. RHE was 1.6 times as much as that of pristine carbon black (33 mmol L−1 h−1), which was similar with that of pristine carbon black (58.4 mmol L−1 h−1) in an alkaline electrolyte (0.1 M KOH). The finite-element method simulations and experiments indicated that TiO2 could enhance local alkalinity to increase the current density for facilitating 2e− ORR. The density functional theory calculations indicated that the introducing of TiO2 into the CB structure could promote the adsorption of O2, facilitate the adsorption of *OOH and reduce the overpotential, resulting in high activity towards 2e− ORR to H2O2. This work proposes a new strategy for optimizing electrode–electrolyte interface to enhance 2e− ORR performance in neutral electrolytes.

Carbon electrodes for the electrocatalytic synthesis of hydrogen peroxide: A review

Carbon electrodes for the electrocatalytic synthesis of hydrogen peroxide: A review

Selective oxygen-doping in self-supportive carbon electrode by electrochemical oxidation for electrocatalytic synthesis of hydrogen peroxide

We report the selective introduction of oxygen-containing functional groups for two-electron oxygen reduction reaction (2e-ORR) in self-supportive carbon electrode using electrochemical oxidation method. The optimal electrode shows hydrogen peroxide (H2O2) selectivity up to 95 %. CO is found active to control 2e-ORR selectivity and mechanism of oxygen species variation is elucidated by in situ infrared reflection absorption spectroscopy. We further improve mass transfer by introducing highly interconnected macropores in electrode, which shows H2O2 yield of 144 mmol cm−2 h−1 and Faradaic efficiency of nearly 100 %. These may inspire advanced active electrode creation for applications through selective electrochemical doping and structural design.

Enhancing H2O2 Electrosynthesis at Industrial-Relevant Current in Acidic Media on Diatomic Cobalt Sites.

Electrocatalytic synthesis of hydrogen peroxide (H2O2) in acidic media is an efficient and eco-friendly approach to produce inherently stable H2O2, but limited by the lack of selective and stable catalysts under industrial-relevant current densities. Herein, we report a diatomic cobalt catalyst for two-electron oxygen reduction to efficiently produce H2O2 at 50-400 mA cm-2 in acid. Electrode kinetics study shows a >95% selectivity for two-electron oxygen reduction on the diatomic cobalt sites. In a flow cell device, a record-high production rate of 11.72 mol gcat-1 h-1 and exceptional long-term stability (100 h) are realized under high current densities. In situ spectroscopic studies and theoretical calculations reveal that introducing a second metal into the coordination sphere of the cobalt site can optimize the binding strength of key H2O2 intermediates due to the downshifted d-band center of cobalt. We also demonstrate the feasibility of processing municipal plastic wastes through decentralized H2O2 production.

Electrocatalytic synthesis of hydrogen peroxide based on multi-doped carbon-based nanocatalyst

In this study, a nickel, nitrogen and oxygen co-doped nanocatalyst (Ni–N/Cox) was prepared and the catalyst exhibited excellent 2e− ORR activity under alkaline condition with a remarkable selectivity for hydrogen peroxide of up to 96%.

Covalent Organic Frameworks with Molecular Electronic Modulation as Metal‐Free Electrocatalysts for Efficient Hydrogen Peroxide Production

Tuning the electronic property of active center to balance the adsorption ability and reactivity of oxygen is essential for achieving 2e− oxygen reduction reaction (ORR) for electrocatalytic synthesis of hydrogen peroxide (H2O2), still represents a grand challenge. Herein, different by‐design building blocks are introduced to regulate the electronic structure of catalytically active centers in covalent organic frameworks (COFs). Theoretical calculation reveals that adsorption ability of oxygen molecule (O2) can be finely tuned by the regulation of electronic structure and the binding strength of O2 is positively correlated with the electron donating ability of active center. As a result, the newly designed TP‐TD‐COF shows higher 2e− ORR activity and selectivity owing to the stronger electron donating ability and the higher adsorption strength of O2 on electron‐rich active center. This study reveals fundamental structure–activity relationship in H2O2 synthesis and offers a strategy for designing metal‐free COF catalysts through rational modulation of their electronic properties at molecular level.

Activated Ni-based metal–organic framework catalyst with well-defined structure for electrosynthesis of hydrogen peroxide

Catalyst with well-defined active sites and highly ordered mesoporous structure is of significant importance for electrocatalytic synthesis of hydrogen peroxide (H2O2) by a two-electron oxygen reduction reaction (ORR). Herein, we present a Ni-based MOF two-electron ORR electrocatalyst derived from zeolitic imidazolate framework-8 (ZIF-8) for H2O2 production. The partial substitution of Zn in ZIF-8 with Ni (MOF Ni-250) affords a favorable two-electron ORR catalytic performance, where the elemental Ni serves as an excellent active site. In addition, the catalytic performance of the catalyst is further enhanced by calcination treatment of MOF Ni-250 under 300 ℃ (c-MOF Ni-250), which removes the crystal water and other small molecules within MOF, thus exposing the active sites and transfer channel of reaction species in catalyst layer without structure destruction. The optimized c-MOF Ni-250 exhibits an excellent H2O2 selectivity of 95% and a high H2O2 production rate of 0.51 mol·gcat.-1·h−1 at 0.37 V (vs. RHE) in 0.1 M KOH. The acitve sites of Ni atom is futher confirmed by using density functional theory (DFT) calculations. This finding demonstrates that the as-developed catalyst has a great potential in electrocatalytic synthesis of H2O2 in practical applications.

Molecule Confined Isolated Metal Sites Enable the Electrocatalytic Synthesis of Hydrogen Peroxide.

The direct synthesis of hydrogen peroxide (H2 O2 ) through the two-electron oxygen reduction reaction is a promising alternative to the industrial anthraquinone oxidation process. Selectivity to H2 O2 is however limited by the four-electron pathway during oxygen reduction. Herein, it is reported that aminoanthraquinone confined isolated metal sites on carbon supports selectively steer oxygen reduction to H2 O2 through the two-electron pathway. Confining isolated NiNx sites under aminoanthraquinone increases the selectivity to H2 O2 from below 55% to above 80% over a wide potential range. Spectroscopy characterization and density functional theory calculations indicate that isolated NiNx sites are confined within a nanochannel formed between the molecule and the carbon support. The confinement reduces the thermodynamic barrier for OOH* desorption versus further dissociation, thus increasing the selectivity to H2 O2 . It is revealed how tailoring noncovalent interactions beyond the binding site can empower electrocatalysts for the direct synthesis of H2 O2 through oxygen reduction.

Electrocatalytic Synthesis of Hydrogen Peroxide over Au/TiO2 and Electrochemical Trace of OOH* Intermediate.

In this work, a series of gold-supported titanium oxide composites have been prepared and high selectivity (over 90%) of hydrogen peroxide is achieved. For the first time, electrochemical impedance spectroscopy and electron spin resonance analysis demonstrate that high charge transfer impedance of the catalyst can suppress the decomposition of OOH* intermediates thus promoting the two-electron process of the oxygen reduction reaction.

Ni3B as a highly efficient and selective catalyst for the electrosynthesis of hydrogen peroxide

Electrocatalytic synthesis of hydrogen peroxide (H2O2) via the two-electron oxygen reduction reaction (2e− ORR) is an ideal method for the on-site H2O2 production. Herein, Ni3B is identified as an active, selective, and stable catalyst for ORR to generate H2O2, which exhibits a high selectivity of over 90 % and an onset potential of ∼0.7 V versus the reversible hydrogen electrode (RHE). Furthermore, the mass activity of Ni3B is about 16.5 A g-1 at 0.52 V (RHE), which is comparable to some noble metal alloys. Our experimental results suggest that the high performance of Ni3B originates from the alloying process of Ni and B atoms. The density functional theory calculations reveal that the inner B atoms with high electronegativity decrease the state density of Ni-3d orbital near the Fermi level relative to Ni, which optimizes the binding energy of OOH* and makes Ni3B a highly efficient and stable catalyst for the two-electron ORR.

Carbon-based materials for photo- and electrocatalytic synthesis of hydrogen peroxide.

The high demand for hydrogen peroxide (H2O2) has been dominantly supplied by the anthraquinone process for various applications globally, including chemical synthesis and wastewater treatment. However, the centralized manufacturing and intensive energy input and waste output are significant challenges associated with this process. Accordingly, the on-site production of H2O2via electro- and photocatalytic water oxidation and oxygen reduction partially is greener and easier to handle and has recently emerged with extensive research aiming to seek active, selective and stable catalysts. Herein, we review the current status and future perspectives in this field focused on carbon-based catalysts and their hybrids, since they are relatively inexpensive, bio-friendly and flexible for structural modulation. We present state-of-the-art progress, typical strategies for catalyst engineering towards selective and active H2O2 production, discussion on electro- and photochemical mechanisms and H2O2 formation through both reductive and oxidative reaction pathways, and conclude with the key challenges to be overcome. We expect promising developments would be inspired in the near future towards practical decentralized H2O2 production and its direct use.

Sodium ferric EDTA-derived Fe-N-C material for selectively electrocatalytic synthesis of hydrogen peroxide

A cheap sodium ferric EDTA-derived material (EDTAFeNa-KB-HT1) was prepared via one-step pyrolysis of a complex of Ketjenblack EC-300J and inorganic-organic hybrid EDTAFeNa, which was employed as both nitrogen and ferric precursors. The EDTAFeNa-KB-HT1 was proved to be an iron and nitrogen co-doped Fe-N-C material with micro-mesoporous structure and large surface area. The EDTAFeNa-KB-HT1 exhibited high selectivity (80–100%) towards oxygen reduction reaction for electrocatalytic synthesis of hydrogen peroxide (H2O2) concurrently with generation of large current density, which could be potentially a safe, efficient and environment-friendly fuel cell method for the scale production of H2O2.

Electrocatalytic synthesis of hydrogen peroxide on Au-Pd nanoparticles: From fundamentals to continuous production

The electrochemical synthesis of hydrogen peroxide (H2O2) represents a promising alternative to the anthraquinone process, as it combines on-site chemical and electrical production. The design of selective electrocatalysts is challenging and is commonly based on the alloying of elements to generate a synergistic effect and increase activity. In the present work, we report the electrochemical activity of Au-Pd nanoparticles immobilized directly onto an electrode as a model to study H2O2 electrochemical synthesis from fundamentals to continuous production. The impact of composition on the oxygen reduction reaction (ORR), the selectivity, as well as the peroxide reduction and oxidation reactions (PROR) are studied.

Electrocatalytic Synthesis of Hydrogen Peroxide on Non-Precious Catalysts

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Mesoporous Nitrogen-Doped Carbon for the Electrocatalytic Synthesis of Hydrogen Peroxide

Mesoporous nitrogen-doped carbon derived from the ionic liquid N-butyl-3-methylpyridinium dicyanamide is a highly active, cheap, and selective metal-free catalyst for the electrochemical synthesis of hydrogen peroxide that has the potential for use in a safe, sustainable, and cheap flow-reactor-based method for H(2)O(2) production.