Flores-Lasluisa Jhony X, Huerta Francisco, Cazorla-Amorós Diego, Morallon Emilia
Departamento Química Física e Instituto Universitario de Materiales, Universidad de Alicante, Ap. 99, E-03080 Alicante, Spain.
Departamento Ingenieria Textil y Papelera, Universitat Politecnica de Valencia, Plaza Ferrandiz y Carbonell, 1, E-03801 Alcoy, Spain.
Nanomaterials (Basel). 2020 Nov 30;10(12):2394. doi: 10.3390/nano10122394.
LaMnCoO perovskites were synthesized by a modified sol-gel method which incorporates EDTA. These materials' electrochemical activity towards both oxygen reduction (ORR) and oxygen evolution reactions (OER) was studied. The cobalt substitution level determines some physicochemical properties and, particularly, the surface concentration of Co and Mn's different oxidation states. As a result, the electroactivity of perovskite materials can be tuned using their composition. The presence of cobalt at low concentration influences the catalytic activity positively, and better bifunctionality is attained. As in other perovskites, their low electrical conductivity limits their applicability in electrochemical devices. It was found that the electrochemical performance improved significantly by physically mixing with a mortar the active materials with two different carbon black materials. The existence of a synergistic effect between the electroactive component and the carbon material was interpreted in light of the strong carbon-oxygen-metal interaction. Some mixed samples are promising electrocatalysts towards both ORR and OER.
通过结合乙二胺四乙酸（EDTA）的改进溶胶-凝胶法合成了LaMnCoO钙钛矿。研究了这些材料对氧还原反应（ORR）和析氧反应（OER）的电化学活性。钴取代水平决定了一些物理化学性质，特别是Co和Mn不同氧化态的表面浓度。因此，钙钛矿材料的电活性可以通过其组成来调节。低浓度钴的存在对催化活性有积极影响，并获得了更好的双功能。与其他钙钛矿一样，它们的低电导率限制了它们在电化学装置中的应用。研究发现，通过将活性材料与两种不同的炭黑材料用研钵物理混合，电化学性能显著提高。根据强碳-氧-金属相互作用解释了电活性组分与碳材料之间协同效应的存在。一些混合样品是对ORR和OER都有前景的电催化剂。
