Single-Ni Sites Embedded in Multilayer Nitrogen-Doped Graphene Derived from Amino-Functionalized MOF for Highly Selective CO2 Electroreduction,ACS Sustainable Chemistry & Engineering

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Single-Ni Sites Embedded in Multilayer Nitrogen-Doped Graphene Derived from Amino-Functionalized MOF for Highly Selective CO2 Electroreduction
ACS Sustainable Chemistry & Engineering ( IF 7.1 ) Pub Date : 2021-03-03 , DOI: 10.1021/acssuschemeng.0c08749
Haojing Wang ₁ , Guanyu Liu _{1,

2} , Chunping Chen ₃ , Wenguang Tu ₁ , Yan Lu _{1,

2} , Shuyang Wu _{1,

2} , Dermot O’Hare ₃ , Rong Xu _{1,

2}

Affiliation

CO₂ electroreduction using renewable electricity is a promising pathway for CO₂ utilization. However, the development of highly active and selective catalysts for CO₂ reduction still poses significant challenges. Here, we report the use of an amino-functionalized metal–organic framework as a precursor to derive Ni-N-C active sites embedded in multilayer graphene shells as the dominant active sites for CO₂ electroreduction. During the process of high-temperature annealing and acid washing, the −NH₂ groups in the MOF precursors exhibit a greater tendency to generate structural defects on graphene layers and derive abundant Ni-N-C sites by Ni migration. Aggregated Ni particles, which incline to catalyze the competitive hydrogen evolution reaction, are successfully removed during the posttreatment, exposing numerous Ni-N-C active sites to facilitate the CO₂ electroreduction. The resulting catalyst displays excellent electrochemical CO₂ reduction activity to CO with Faradaic efficiencies above 90% in a wide range of potentials from −0.6 to −1.2 V versus reversible hydrogen electrode. The maximum Faradaic efficiency of 97% can be achieved at a low overpotential of 0.79 V with a CO partial current density of 27.2 mA cm^–2, which is among the best performance of Ni-based electrocatalysts reported so far. This work provides useful insights into the tuning of the metal sites by the coordination environment of MOFs toward the fabrication of highly active and selective electrocatalysts for CO₂ reduction.

中文翻译：

氨基官能化MOF衍生的多层氮掺杂石墨烯中嵌入的单镍位点，用于高选择性CO ₂电还原

CO ₂电还原使用可再生电力是用于CO有希望的途径₂的利用率。但是，开发用于还原CO ₂的高活性和选择性催化剂仍然构成重大挑战。在这里，我们报道了使用氨基官能化的金属有机框架作为前体，以衍生嵌入多层石墨烯壳层的Ni-NC活性位点，将其作为CO ₂电还原的主要活性位点。在高温退火和酸洗过程中，-NH ₂MOF前体中的基团显示出更大的趋势，可在石墨烯层上产生结构缺陷并通过Ni迁移获得大量的Ni-NC位点。倾向于催化竞争性氢释放反应的聚集的Ni颗粒在后处理过程中被成功去除，暴露出大量的Ni-NC活性位点以促进CO _2的电还原。相对于可逆氢电极，所得催化剂在-0.6至-1.2 V的大范围电势下，具有法拉第效率高于90％的出色的CO ₂电化学还原成CO的活性。在0.79 V的低过电位和27.2 mA cm ^–2的CO分流密度下，可以实现97％的最大法拉第效率。，这是迄今为止报道的镍基电催化剂性能最好的表现之一。这项工作为通过MOF的配位环境向金属位点的调节提供了有用的见解，以制造用于还原CO ₂的高活性和选择性电催化剂。

更新日期：2021-03-15

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