Breaking the limitations of activity and stability in powdered materials for oxygen evolution reaction: The critical role of catalyst-inducing seeds

Powdered catalysts are extensively employed in industrial-scale energy conversion devices but struggle with weak powder-substrate adhesion and inherent instability in gas-evolving and highly oxidative oxygen evolution reactions (OER). This work introduces an innovative strategy in which powdered materials serve a critical role as catalyst-inducing seeds to break these limitations. Specifically, powdered Ti₂CT_x MXene with anchored cobalt single atoms (Co-SAs) shows negligible catalytic activity on its own but serves as catalyst-inducing seeds, significantly enhancing the catalytic activity of the conductive FeNi substrate. Mechanistic studies demonstrate that Co-SAs accelerate the oxidation rate of Ti₂CT_x, leading to the micro-battery corrosion behavior between oxidized Co/Ti₂CT_x and FeNi alloy, which generates highly OER-active corrosion products tightly bonded to FeNi alloy, thereby enhancing catalytic activity and ensuring stability. The prepared porous electrode shows a low overpotential of 303 mV to deliver an ultra-high current density of 1000 mA cm⁻² and maintains activity for 1200 hours under high current density conditions, rivaling advanced self-supporting electrodes. Moreover, replacing Co in Co/Ti₂CT_x with metals like Fe, Ni or Mn, yields comparable effects, suggesting the scalability of catalyst-inducing seeds. This approach breaks traditional limitations of powdered materials in OER, offering an effective pathway to engineer advanced catalytic electrodes.