<i>In Situ</i> Exsolved Ru and Ni Bimetallic Nanoparticles on Pr _0.7 Sr _0.3 CrO ₃ Boost the H ₂ Oxidation and Production in the Reversible Solid Oxide Fuel Cell

Metallization of perovskite-type fuel electrodes could be an option to enhance electrocatalysis of the H₂ oxidation or H₂ evolution reaction of a reversible solid oxide fuel cell (RSOFC), but one metal alone may not be able to work under both the anodic bias in fuel cell mode and the cathodic bias in electrolysis mode. Therefore, Ni/Ru was doped on the B site of Pr_0.7Sr_0.3CrO₃ (PSC) perovskites to produce nanoparticles during the <i>in situ</i> exsolution in fuel-electrode mode. The cell with the Pr_0.7Sr_0.3Cr_0.85Ni_0.1Ru_0.05O₃ (PSCNR) fuel electrode exhibits a peak power of 1.01 W cm^-2 in the solid oxide fuel cell (SOFC) mode and 1.12 A cm^-2 at 1.3 V in the solid oxide electrolyzer cell (SOEC) mode. The cyclic application of anodic and cathodic bias to the PSC can cause a cyclical enrichment of A and B site cations, resulting in surface destabilization. The degradation of the PSCNR cell with bimetallic Ni and Ru doping was 5.36% in electrolysis mode over the first 20 cycles, which is much lower than that of the PSC perovskite (50.0%) or its single-metal counterparts (30% to 22%). The proximity of Ru and Ni metals can mitigate nickel's instability in water and enhance hydrogen adsorption, fostering a balanced adsorption of reactive species. These findings suggest that bimetallic Ni/Ru doping offers a promising strategy to overcome the limitations of single-metal catalysts, significantly enhancing the durability and performance of perovskite-based electrodes in RSOFCs.