Coral-shaped Mn-CuS with hierarchical pores and crystalline defects for high-efficiency H2O2 production via electrocatalytic two-electron reduction.

We report the development of non-noble transition metal sulfide catalysts Mn-CuS-x for high-efficiency and selective H 2 O 2 production. In this study, we synthesized Mn-CuS-x with coral-shaped hierarchical porous structure through one-pot hydrothermal reaction. The Mn-CuS-x possesses large specific surface area with plenty of crystalline defects via heteroatom doping of Mn. The Mn-CuS-x kinetically favored 2e− pathway over 4e− pathway, resulting in high selectivity (>92%) to H 2 O 2 production and high H 2 O 2 concentration (∼24.5 mM at 0.6 V vs. RHE) within 3 h for the optimized Mn-CuS-2 catalysts (synthesized with a molar ratio of 1:3:8 (MnCl 2 ·4 H 2 O: CuCl 2 ·2 H 2 O: C 2 H 5 NS)). The Mn-CuS-2 showed excellent stability, indicating that the Mn-CuS electrocatalysts can simultaneously achieve both high stability and enhanced H 2 O 2 production. Our first-principles calculations further confirmed that the heteroatom Mn doping to CuS thermodynamically makes the 2e–-ORR pathway more favorable. This study provides a green, low-cost, and efficient route to produce H 2 O 2 , which is very promising for generating chemicals and liquid fuels. [Display omitted] • Coral-shaped Mn-CuS is synthesized via one-pot hydrothermal reaction. • The Mn-CuS possesses hierarchical porous structure and large specific surface area. • A large number of crystalline defects are introduced into the Mn-CuS via Mn doping. • The 2e− pathway is kinetically favored over 4e− pathway to H 2 O 2 for Mn-CuS. • The Mn-CuS shows high selectivity (>92%) and H 2 O 2 concentration ∼24.5 mM at 0.6 V. [ABSTRACT FROM AUTHOR]