A cracked carbon matrix decorated with amorphous IrOx for boosting the oxygen evolution reaction in electrochemical water splitting

Abstract

Numerous studies have been performed to develop better materials and systems to boost H₂ production by water splitting. IrO₂ and Ti felt have been conventionally used in proton exchange membrane water electrolyzers (PEMWE) as anode catalysts and porous transport layers (PTLs), respectively. In this study, a cracked carbon matrix (CM) and amorphous IrO_x nanoparticles were introduced to overcome the limitations of the current materials. Amorphous IrO_x protected by thin carbon shells exhibited higher electrocatalytic activity for the O₂ evolution reaction than commercial IrO₂ and ensured sufficient durability under highly oxidative conditions. CM provided a sufficient surface area to disperse the IrO_x nanoparticles, and its cracked nature facilitated the transport of electrolytes and produced O₂. These merits enabled PEMWE to achieve 1 A cm⁻² at a cell voltage of 1.64 V without severe degradation.