Polymer Entrapment Flash Pyrolysis for the Preparation of Nanoscale Iridium‐Free Oxygen Evolution Electrocatalysts

Abstract This paper describes the use of a new polymer entrapment flash pyrolysis (PEFP) method for making nanoscale yttrium ruthenate (Y₂Ru₂O_7‐δ) electrocatalysts. This approach effectively reduced the synthesis temperature of phase‐pure pyrochlore catalysts from 1000 °C to 550 °C, and greatly suppressed the sintering of catalyst particles. The supported nanocrystalline Y₂Ru₂O_7‐δ catalysts showed enhanced activity towards oxygen evolution reaction (OER) in acidic electrolyte and were stable at 1.50 V for the comparative study (>20 h) under the current density of 10 mA/cm²_geo in chronopotentiometry testing. This is equivalent to an overpotential value of 270 mV, about half of that of the reference IrO₂ catalyst. X‐ray absorption spectroscopy (XAS) and transmission electron microscopy (TEM) analysis showed that the high‐surface‐area Y₂Ru₂O_7‐δ catalyst had an oxygen‐deficient structure. This study provides a route to the synthesis of fine ceramic (or oxide)‐based electrocatalysts for making high‐performing electrocatalysts.