Bimetallic coordination polymers synthesized from pyrazine dicarboxylic acid serve as efficient electrocatalysts for enhancing the oxygen evolution reaction

Abstract

The pursuit of cost-effective and efficient electrocatalysts for water oxidation is crucial for various applications for the storage and conversion of electrochemical energy. Coordination polymers (CPs) have garnered significant interest as potential electrocatalysts, as their catalytic efficiency can be precisely tuned through the design of coordination layers that boast highly accessible and highly reactive metal sites. However, CP-based catalysts face substantial challenges for their application in electrocatalytic oxidation processes because of their limited activity and poor stability. In this study, we employed a mixed-metal approach to develop CoxNi1-x-PDAs incorporating two functional sites specifically designed for facilitating the oxidation of water. The presence of both Co and Ni enhances electron transport through synergistic effects within the CoxNi1-x-PDAs structure. By adjusting the metal ratios in these coordination polymers, an optimized Co3/4Ni1/4-PDA demonstrated impressive performance in water oxidation under alkaline conditions during oxygen evolution reactions, a current density of 10 mA cm−2 was achieved with an overpotential of 322 mV, along with a Tafel slope measured at 87 mV dec−1. This approach involving mixed metals seeks to exploit the synergistic effects among various metal centers, which could result in efficient electrocatalysts for the oxidation of small molecules. Our findings present a promising avenue for utilizing CPs materials within the realm of electrocatalysis.