Encoding Metal–Cation Arrangements in Metal–Organic Frameworks for Programming the Composition of Electrocatalytically Active Multimetal Oxides

In the present contribution, we report how through the use of metal–organic frameworks (MOFs) composed of addressable combinations of up to four different metal elements it is possible to program the composition of multimetal oxides, which are not attainable by other synthetic methodologies. Thus, due to the ability to distribute multiple metal cations at specific locations in the MOF secondary building units it is possible to code and transfer selected metal ratios to multimetal oxides with novel, desired compositions through a simple calcination process. The demonstration of an enhancement in the electrocatalytic activity of new oxides by preadjusting the metal ratios is here reported for the oxygen reduction reaction, for which activity values comparable to commercial Pt/C catalysts are reached, while showing long stability and methanol tolerance.本研究报道了如下策略：通过使用由最多四种不同金属元素的可定制组合构成的金属有机框架（Metal–Organic Frameworks, MOFs），可程序化调控多金属氧化物的组成——这类多金属氧化物无法通过其他合成方法获得。鉴于可在MOF的次级结构单元的特定位点排布多种金属阳离子，我们可通过简单的煅烧工艺，将预设的金属比例编码并转移至具有新颖目标组成的多金属氧化物中。本研究同时证实，通过预先调控金属比例，可显著提升新型氧化物的电催化活性：针对氧还原反应（Oxygen Reduction Reaction），所制备的催化剂活性可媲美商用Pt/C催化剂，同时兼具优异的长期稳定性与甲醇耐受性。