中国海洋大学Minghua Huang团队在研究中取得进展。他们的最新研究探明了基于钴的金属-有机骨架促进析氧反应的可控缺陷工程。这一研究成果于2023年12月20日发表在国际顶尖学术期刊《结构化学》上。

在该文中，通过一锅溶剂热合成与NaBH₄化学还原工艺耦合，研究人员构建了氧缺陷浓度调节的Co-MOF-Dx催化剂。实验结果表明，随着NaBH₄含量的增加，Co-MOF-Dx内部的氧缺陷浓度逐渐增加，这为钴活性位点周围的电子结构定制和优化氧中间体的吸附/解吸能力提供了一个灵活的平台。

当NaBH₄的引入量达到5 mg时，所产生的丰富的不饱和配位缺陷可以使Co-MOF-D5催化剂，具有优化的电子结构和更多暴露的活性位点，从而提高电荷转移和吸附/解吸能力。结果表明，在碱性介质中，优化后的Co-MOF-D5能在仅300 mV的低过电位下驱动10 mA cm^-2的电流密度，Tafel斜率仅为53.1 mV dec^-1。这项工作为通过调节缺陷浓度来开发高性能的MOF催化剂指明了方向。

据了解，金属有机骨架(MOFs)缺陷工程为合理设计低过电位、高稳定性的高级析氧反应(OER)催化剂提供了高度的灵活性。然而，对缺陷浓度对催化OER活性的影响的基本认识仍然很模糊。

附：英文原文

Title: Controllable defect engineering based on cobalt metal-organic framework for boosting oxygen evolution reaction

Author: anonymous

Issue&Volume: 2023-12-20

Abstract: Defect engineering on metal-organic frameworks (MOFs) provides the high flexibility to rationally design advanced oxygen evolution reaction (OER) catalysts with low overpotential and high stability. However, fundamental understanding the effect of defect concentration on catalytic OER activity is still quite ambiguous. Herein, the Co-MOF-Dx catalysts with regulated oxygen defects concentration are deliberately constructed via coupling one-pot solvothermal synthesis with NaBH4 chemical reduction process. Experimental findings propose that the oxygen defect concentration within Co-MOF-Dx gradually increases with raising the NaBH4 content, which could provide a flexible platform to tailor the electronic structure around active Co site and optimize adsorption/desorption capacity of oxygen intermediates. When the introduction content of NaBH4 is up to 5 mg, the resulting abundant unsaturated coordination defects could endow the Co-MOF-D5 catalyst with optimized electronic structure and more exposed active sites for improving charge transfer and adsorption/desorption capacity. It is found that the optimized Co-MOF-D5 can drive the current density of 10 mA cm-2 only at a low overpotential of 300 mV with the small Tafel slope of 53.1 mV dec-1 in alkaline medium. This work sheds light on the way for the development of high-performance MOF catalysts via modulating defect concentration.

DOI: 10.1016/j.cjsc.2023.100210

Source: http://cjsc.ac.cn/cms/issues/544