Bimetallic and surface-functionalized aerogels for the efficient electroreduction of CO2 to added-value products

双金属和表面功能化气凝胶，用于有效地将二氧化碳电还原为附加值产品

• 批准号: 251453020
• 负责人: Professor Dr. Alexander Eychmüller
• 金额: --
• 依托单位: Professur für Physikalische Chemie
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2014
• 资助国家: 德国
• 起止时间: 2013-12-31 至 2021-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/251453020?language=en
• 关键词: Bimetallic; surface; functionalized; aerogels; efficient

In the ongoing transition towards the generalized use of emission-neutral energy production, storage and conversion technologies, the use of intermittent electricity to electrochemically reduce CO2 into added-value chemicals (e.g., CO or HCOO−) is increasingly appealing. However, the commercial success of this CO2-valorization approach passes by the development of co-electrolysis cells capable of reaching current densities ≥ 200 mA∙cmgeom-2, which in terms requires highly-dispersed and -active materials for catalyzing the reactions taking place inside the cell. Among these, the electroreduction of CO2 is particularly challenging, not only due to the large overpotential that it requires, but also in sight of the difficulties associated to the control of its product selectivity. These key features can be optimized by tuning the adsorption properties of the reaction’s intermediates on the catalyst’s surface, e.g., by shifting the position of its d-band center or by adding other adsorbates that modify the interactions among these intermediates and the surface. The work presented herein explores both of these approaches by tackling the synthesis of high surface area, tridimensional nano-networks (aerogels) with bi-metallic compositions (PtPd or AuCu alloys/cores-hells) or with their surface functionalized with adsorbed N-containing ligands, respectively. Following a systematic study of the effect of various synthesis parameters on the aerogels’ structure and surface vs. bulk composition, electrochemical measurements complemented by operando X-ray absorption spectroscopy will shed light on the extent to which these parameters determine the gels’ reactivity. The subsequent implementation of selected aerogels in an in-house co-electrolysis cell will allow (for the first time) to verify whether the reactivity trends observed in aqueous electrochemical tests (customarily used in the field) extend to the application-relevant co-electrolysis setup. Most importantly, these results will serve to assess the commercial feasibility of this CO2-to-products approach, in terms of the maximum efficiencies and product-specific currents (i.e., operative potentials and selectivities) attainable in this device.

在向排放中性能源生产、储存和转换技术的普遍使用的持续过渡中，使用间歇性电力以电化学方式将CO2还原为增值化学品（例如，CO或HCOO-）越来越有吸引力。然而，这种CO2稳定方法的商业成功通过能够达到≥ 200 mA/cmgeom-2的电流密度的共电解池的开发，这就需要高度分散的活性材料来催化电池内发生的反应。其中，CO2的电还原是特别具有挑战性的，这不仅是因为它需要大的过电位，而且还考虑到与控制其产物选择性相关的困难。这些关键特征可以通过调节反应中间体在催化剂表面上的吸附性质来优化，例如，通过移动其d带中心的位置或通过添加改变这些中间体和表面之间的相互作用的其它吸附物。本文提出的工作探索了这两种方法，通过处理合成高表面积，三维纳米网络（气凝胶）与双金属组合物（PtPd或AuCu合金/核壳）或与它们的表面功能化吸附的含N配体，分别。在系统研究了各种合成参数对气凝胶结构和表面与本体组成的影响之后，电化学测量辅以操作X射线吸收光谱将揭示这些参数决定凝胶反应性的程度。随后在内部共电解池中实施选定的气凝胶将允许（第一次）验证在水性电化学测试（通常在该领域中使用）中观察到的反应性趋势是否延伸到与应用相关的共电解设置。最重要的是，这些结果将用于评估这种CO2到产品方法的商业可行性，在最大效率和产品特定电流方面（即，操作电位和选择性）。