A critical role of bond competition in tailoring Mn valence state and bifunctional electrocatalyst activity of manganese oxide is evidenced by the remarkable improvement of the electrocatalyst activity of α-MnO₂ upon the partial substitution of electronegative Ru⁴⁺ ion. The replacement of Mn⁴⁺ ion with more electronegative Ru⁴⁺ one is quite effective in weakening adjacent (Mn−O) bonds in terms of bond competition, leading to the stabilization of Jahn-Teller active Mn³⁺ species, as well as in providing electrocatalytically active Ru sites. The resulting Ru-substituted α-Mn_1−xRu_xO₂ nanowires show much higher electrocatalyst activities for both oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) than does the physical mixture of α-MnO₂ and RuO₂, indicating the main role of (Mn−O) bond covalency in the optimization of the bifunctional electrocatalyst activity of manganese oxide. The present study underscores that, like the previous strategy of structural disorder enhancement, the substitution of highly electronegative cation can provide a novel efficient way of improving the electrocatalyst performance of manganese oxide via the bond competition between adjacent (Ru−O) and (Mn−O) bonds.

键竞争的剪裁的Mn的价态和氧化锰的双功能电活性的关键作用是由α-MnO的的电活性的显着提高所证明₂在电负性的Ru的部分取代⁴⁺离子。在键竞争方面，用更多带负电的Ru ⁴⁺代替Mn ⁴⁺离子对于减弱相邻的（Mn-O）键非常有效，从而导致Jahn-Teller活性Mn ³⁺物种的稳定以及提供电催化活性Ru位点。生成的Ru取代的α-Mn1 _-x Ru _x O ₂纳米线显示了两个析氧反应高得多的电活动（OER）和比确实α-MnO的的物理混合物的氧还原反应（ORR）₂和的RuO ₂，表明（MNO）共价键中的优化的主要作用锰的双功能电催化剂活性 本研究强调，像以前的结构紊乱增强策略一样，高电负性阳离子的取代可以通过相邻的（Ru-O）和（Mn- O）债券。