Scalable neutral H<sub>2</sub>O<sub>2</sub> electrosynthesis by platinum diphosphide nanocrystals by regulating oxygen reduction reaction pathways.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 32764644.
- Also identified by DOI 10.1038/s41467-020-17584-9 and PMC identifier 7411044.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Despite progress in small scale electrocatalytic production of hydrogen peroxide (H<sub>2</sub>O<sub>2</sub>) using a rotating ring-disk electrode, further work is needed to develop a non-toxic, selective, and stable O<sub>2</sub>-to-H<sub>2</sub>O<sub>2</sub> electrocatalyst for realizing continuous on-site production of neutral hydrogen peroxide. We report ultrasmall and monodisperse colloidal PtP<sub>2</sub> nanocrystals that achieve H<sub>2</sub>O<sub>2</sub> production at near zero-overpotential with near unity H<sub>2</sub>O<sub>2</sub> selectivity at 0.27 V vs. RHE. Density functional theory calculations indicate that P promotes hydrogenation of OOH* to H<sub>2</sub>O<sub>2</sub> by weakening the Pt-OOH* bond and suppressing the dissociative OOH* to O* pathway. Atomic layer deposition of Al<sub>2</sub>O<sub>3</sub> prevents NC aggregation and enables application in a polymer electrolyte membrane fuel cell (PEMFC) with a maximum r(H<sub>2</sub>O<sub>2</sub>) of 2.26 mmol h<sup>-1</sup> cm<sup>-2</sup> and a current efficiency of 78.8% even at a high current density of 150 mA cm<sup>-2</sup>. Catalyst stability enables an accumulated neutral H<sub>2</sub>O<sub>2</sub> concentration in 600 mL of 3.0 wt% (pH = 6.6).