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...

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

Ullmann's Encyclopedia of industrial chemistry (Wiley)

Oxygen reduction reaction towards hydrogen peroxide (H2O2) provides a green alternative route for H2O2 production, but it lacks efficient catalysts to achieve high selectivity and activity simultaneously under industrial-relevant production rates. Here we report a boron-doped carbon (B-C) catalyst which can overcome this activity-selectivity dilemma. Compared to the state-of-the-art oxidized carbon catalyst, B-C catalyst presents enhanced activity (saving more than 210 mV overpotential) under industrial-relevant currents (up to 300 mA cm−2) while maintaining high H2O2 selectivity (85–90%). Density-functional theory calculations reveal that the boron dopant site is responsible for high H2O2 activity and selectivity due to low thermodynamic and kinetic barriers. Employed in our porous solid electrolyte reactor, the B-C catalyst demonstrates a direct and continuous generation of pure H2O2 solutions with high selectivity (up to 95%) and high H2O2 partial currents (up to ~400 mA cm−2), illustrating the catalyst’s great potential for practical applications in the future. Oxygen reduction reaction provides an environmentally-benign route for hydrogen peroxide production but lacks efficient catalysts to achieve high selectivity and activity simultaneously. Here, the authors report a boron-doped carbon catalyst which shows great promise with outstanding performance.

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Highly active and selective oxygen reduction to H2O2 on boron-doped carbon for high production rates

Electrocatalytic Oxygen Reduction to Hydrogen Peroxide: From Homogeneous to Heterogeneous Electrocatalysis

Hydrogen peroxide (H2 O2 ), as a green fuel and oxidant, has drawn increasing attention in the energy and environmental research. Compared with the traditional anthraquinone process, the electrochemical (EC) and photoelectrochemical (PEC) syntheses of H2 O2 are cost-effective and environmentally friendly. In order to construct membraneless EC/PEC devices for the full H2 O2 synthesis, anodic H2 O2 production by water oxidation, which is less developed than cathodic H2 O2 generation, is highly desirable. Here, we review recent developments for the EC/PEC H2 O2 production by water oxidation, including fundamental aspects, benchmarking activity evaluation, material/catalyst selection, and strategies for increasing selectivity, efficiency, and accumulation. Furthermore, we discuss the challenges and outlook of water oxidation for H2 O2 production, especially device-level development, accumulation and stability, and industrial applications. Our review is intended to stimulate studies further improving EC/PEC H2 O2 production.

Electrochemical and Photoelectrochemical Water Oxidation for Hydrogen Peroxide Production

Electrochemical synthesis of H2O2 through a selective two-electron (2e-) oxygen reduction reaction (ORR) is an attractive alternative to the industrial anthraquinone oxidation method, as it allows decentralized H2O2 production. Herein, we report that the synergistic interaction between partially oxidized palladium (Pdδ+) and oxygen-functionalized carbon can promote 2e- ORR in acidic electrolytes. An electrocatalyst synthesized by solution deposition of amorphous Pdδ+ clusters (Pd3δ+ and Pd4δ+) onto mildly oxidized carbon nanotubes (Pdδ+-OCNT) shows nearly 100% selectivity toward H2O2 and a positive shift of ORR onset potential by ~320 mV compared with the OCNT substrate. A high mass activity (1.946 A mg-1 at 0.45 V) of Pdδ+-OCNT is achieved. Extended X-ray absorption fine structure characterization and density functional theory calculations suggest that the interaction between Pd clusters and the nearby oxygen-containing functional groups is key for the high selectivity and activity for 2e- ORR.

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Ying Zhang

Papers

Promoting H2O2 production via 2-electron oxygen reduction by coordinating partially oxidized Pd with defect carbon.