RESUMEN
The deactivation of ozone decomposition catalysts has been a bottleneck in their industrial application. As an efficient catalyst regeneration method, the liquid-phase method has attracted wide attention due to its operability and universality. However, the amount of waste liquid generated by the used regeneration liquid is a major drawback of its application. Therefore, we propose an electrolytic regeneration method for cyclic regeneration of MnOx ozone decomposition catalysts by combining the advantages of the electrolytic process. In this method, NaNO2 solution is used to react with O22- to efficiently regenerate the inactivated MnOx catalysts, while NO2- is oxidized to NO3-, and then the oxidized NO3- can be efficiently reduced to NO2- through the electrolysis process at the cathode with an 88% Faraday efficiency, ultimately realizing the recycling of the NO2-/NO3- regeneration solution. By this method, the regeneration of inactivated MnOx ozone catalysts can be realized only using electricity.
RESUMEN
The development of proton exchange membrane water electrolysis is a promising technology for hydrogen production, which has always been restricted by the slow kinetics of the oxygen evolution reaction (OER). Although IrOx is one of the benchmark acidic OER electrocatalysts, there are still challenges in designing highly active and stable Ir-based electrocatalysts for commercial application. Herein, a Ru-doped IrOx electrocatalyst with abundant twin boundaries (TB-Ru0.3Ir0.7Ox@ITO) is reported, employing indium tin oxide with high conductivity as the support material. Combing the TB-Ru0.3Ir0.7Ox nanoparticles with ITO support could expose more active sites and accelerate the electron transfer. The TB-Ru0.3Ir0.7Ox@ITO exhibits a low overpotential of 203 mV to achieve 10 mA cm-2 and a high mass activity of 854.45 A g-1noble metal at 1.53 V vs RHE toward acidic OER, which exceeds most reported Ir-based OER catalysts. Moreover, improved long-term stability could be obtained, maintaining the reaction for over 110 h at 10 mA cm-2 with negligible deactivation. DFT calculations further reveal the activity enhancement mechanism, demonstrating the synergistic effects of Ru doping and strains on the optimization of the d-band center (εd) position and the adsorption free energy of oxygen intermediates. This work provides ideas to realize the trade-off between high catalytic activity and good stability for acidic OER electrocatalysts.