Two-Dimensional Conductive Ni-HAB as a Catalyst for the Electrochemical Oxygen Reduction Reaction

Authors
Jihye Park,
Zhihua Chen,
Raul A. Flores,
Gustaf Wallnerström,
Ambarish Kulkarni,
Jens K. Nørskov,
Thomas F. Jaramillo,
Zhenan Bao
Year of publication
2020
Journal
ACS Applied Materials & Interfaces
Volume
12
Starting page
39074
Ending page
39081
Catalytic systems whose properties can be systematically tuned via changes in synthesis conditions are highly desirable for the next-generation catalyst design and optimization. Herein, we present a two-dimensional (2D) conductive metal–organic framework consisting of M-N4 units (M = Ni, Cu) and a hexaaminobenzene (HAB) linker as a catalyst for the oxygen reduction reaction. By varying synthetic conditions, we prepared two Ni-HAB catalysts with different crystallinities, resulting in catalytic systems with different electric conductivities, electrochemical activity, and stability. We show that crystallinity has a positive impact on conductivity and demonstrate that this improved crystallinity/conductivity improves the catalytic performance of our model system. Additionally, density functional theory simulations were performed to probe the origin of M-HAB’s catalytic activity, and they suggest that M-HAB’s organic linker acts as the active site with the role of the metal being to modulate the linker sites’ binding strength.
Keywords
metal−organic frameworks
electrical conductivity
electrocatalysis
active sites
oxygen reduction reactions
density functional theory
Funding sources