Interface-Engineered Porous Pt–PdO Nanostructures for Highly Efficient Hydrogen Evolution and Oxidation Reactions in Base and Acid
Rajib Samanta, Ranjit Mishra, Sudip Barman
Abstract
The enhancement of reaction kinetics and durability of the hydrogen evolution/oxidation reaction (HER/HOR) in basic media are necessary for the design of alkaline electrolyzers and fuel cells. In this work, an interface-engineered porous Pt–PdO–N-doped carbon (Pt–PdO/C) composite was synthesized for HER/HOR application in both the acidic and alkaline media. The Pt–PdO/C catalyst delivered an outstanding HER performance and durability in both media. It required 29 and 16 mV overpotential to reach 10 mA/cm2 HER current density in alkaline and acidic media with 36 and 22 mV/dec Tafel slope values, respectively. In addition, Pt–PdO/C showed excellent HOR performance in all pH solutions. The mass-specific exchange current density (i0,m) of this catalyst was 463.8 mA/mgmetal in 0.1 M KOH solution, which was nearly 5.5 times better than that of commercial Pt/C. We demonstrated that both the hydrogen binding energy and OH binding energy are equal descriptors for HER/HOR in the alkaline media. We also investigated the effect of hydroxyl–metal–water species in the electrical double layer on HER/HOR kinetics in a basic medium. The excellent HER/HOR catalytic performance of Pt–PdO/C may be due to the interface engineering, strong synergistic interaction between the components, high electrochemical surface area, porous morphology, and so forth. We hope this work will provide an opportunity to design metal–metal oxide-based electrocatalysts for several renewable energy devices.