Optimisation of the electronic structure by rare earth doping to enhance the bifunctional catalytic activity of perovskites

Understanding the mechanisms by which rare-earth elements modulate the electronic structure and orbital filling of perovskites is essential for designing the highly active catalysts. Herein, by doping the A-site of LaMnO3 with Gd3+, the B-site active center is triggered, which effectively improving the covalency of Mn-O bond and increasing the oxygen vacancy concentration, also boosting the eg orbital filling electron number of La0.8Gd0.2MnO3 closer to 1. Ultimately, the mass activity and turnover frequency of La0.8Gd0.2MnO3 are 2.4 and 4.3 times higher than LaMnO3. DFT calculations show that Gd doping optimises the electronic structure of La0.8Gd0.2MnO3, resulting in modulation of the suitable intermediate adsorption energy, thus improving the catalytic activity. Based on these results, Zinc-air cells were assembled with La0.8Gd0.2MnO3 as the cathode catalyst and exhibited high capacity and cycling stability. This work provides a new perspective for rare-earth optimised the intrinsic properties of perovskites and enhance the bifunctional electrocatalytic performance.