Novel sulfate solid supported binary Ru-Ir oxides for superior electrocatalytic activity towards OER and CER

Abstract

Electrolysis for producing hydrogen powered by renewable electricity can be dramatically expanded by adapting different electrolytes (brine, seawater or pure water), which means the anode materials must stand up to complex electrolyte conditions. Here, a novel catalyst/support hybrid of binary Ru3.5Ir1Ox supported by barium strontium sulfate (BaSrSO4) was synthesized (RuIrOx/BSS) by exchanging the anion ligands of support. The as-synthesized RuIrOx/BSS exhibits compelling oxygen evolution (OER) and chlorine evolution (CER) performances, which affords to 10 mA cm−2 with only overpotential of 244 mV and 38 mV, respectively. The performed X-ray adsorption spectra clearly indicate the presence of an interface charge transfer effect, which results in the assignment of more electrons to the d orbitals of the Ru and Ir sites. The theoretical calculations demonstrated that the electronic structures of the catalytic active sites were modulated to give a lower overpotential, confirming the intrinsically high OER and CER catalytic activity.