The Prospect and Challenge of Hydrogen Peroxide in Constructing High-Performance pH-Disparate Direct Liquid Fuel Cells

Abstract

The interconversion of chemical energy and electrical energy is a promising approach to alleviate the intermittency, fluctuation, and regionality of renewable energy. Direct liquid fuel cells (DLFCs) directly convert the chemical energy in liquid fuel into electricity, although avoiding the storage and transportation problems of gaseous hydrogen, their development has long been limited by the low cell performance. The pH-disparate strategy, which uses alkaline liquid fuel as anode reductant and acidified hydrogen peroxide as the cathode oxidant, has been proposed to fundamentally improve the thermodynamic voltage and cell performance of DLFCs. Herein, the prospect and challenge of hydrogen peroxide in constructing high-performance pH-disparate DLFCs are reviewed and summarized. First, the reaction mechanisms of both hydrogen peroxide oxidation and reduction on different electrocatalysts were elucidated in this review, and then the thermodynamic properties, including pH dependent thermodynamic voltage, energy density, and capacity, of different types of pH-disparate DLFCs were described in detail. Finally, we summarized the impact of the system design and operating conditions on the cell performance of pH-disparate DLFCs. Hopefully, this review will provide a reference guidance for the practical application of hydrogen peroxide in DLFCs.