Understanding the Metal-Support Interaction between Cu and Reducible Metal Oxides during CO2 Hydrogenation through the Use of Well-Defined Surface Models

通过使用明确的表面模型了解 CO2 加氢过程中 Cu 和可还原金属氧化物之间的金属支撑相互作用

• 批准号: 444948747
• 负责人: Professor Dr. Deven Estes
• 金额: --
• 依托单位: Institut für Technische Chemie (ITC)
• 依托单位国家: 德国
• 项目类别: Research Grants
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/444948747?language=en
• 关键词: Understanding; Metal; Support; Interaction; between

Hydrogenation of CO2 (derived from climate neutral sources) to methanol using green-energy sources could be a way of producing sustainable fuels. However, the current catalytic systems for hydrogenating CO2 to methanol, typically consisting of Cu nanoparticles supported on a reducible metal oxide, such as ZnO or ZrO2, are not active enough to be used in such an industrial process. This may be due to a low number of active sites on the surface. These active sites are thought to consist of reduced Zn or Zr sites created through a Strong Metal-Support Interaction (SMSI) in the vicinity of Cu defects. Understanding this SMSI is vital to improving these catalysts. Once we understand the origin of this metal-support interaction, we can increase the number of active sites and thereby the catalytic activity. In this proposal, I describe the development and synthesis of well-defined models of the potential active sites, both homogeneous and on metal oxide surfaces, in order to investigate the SMSI in these catalysts. In section one, we will examine the electrocatalytic activity of molecular complexes containing Zr-O-Zr bridges for CO2 reduction, as molecular models of hydrogen spillover onto the ZrO2 surface. In the second section, reduced Zn and Zr sites will be synthesized directly on the surfaces of ZnO and ZrO2 through the use of Surface Organometallic Chemistry and their reactivity examined by DRIFTS and TPR-MS. In the third section, the reactivity of ZrO2 and ZnO with molecular models of Cu particles, such as Stryker's reagent [HCu(PPh3)]6, will be examined by NMR, UV-Vis, IR, and EPR in the presence and absence of CO2 as a model of the SMSI. In the final stage, we will use the synthetic methods developed thus far to synthesize active sites directly on the surfaces of known catalysts, a strategy termed Active Site Enrichment (ASE). With this method, it will be possible to increase the number of active sites on a working catalyst via simple post-synthetic treatments.

使用绿色能源将二氧化碳(来自气候中性来源)加氢成甲醇可能是生产可持续燃料的一种方式。然而，目前用于二氧化碳加氢合成甲醇的催化体系，通常由负载在可还原金属氧化物(如氧化锌或氧化锆)上的铜纳米颗粒组成，活性不足以用于此类工业过程。这可能是由于表面上的活性中心数量较少所致。这些活性中心被认为是由在铜缺陷附近通过强烈的金属-载体相互作用(SMSi)产生的还原的锌或锆位组成的。了解这种SMSI对于改进这些催化剂至关重要。一旦我们了解了这种金属-载体相互作用的起源，我们就可以增加活性中心的数量，从而提高催化活性。在这项建议中，我描述了定义明确的潜在活性中心的开发和合成模型，包括均相表面和金属氧化物表面，以研究这些催化剂中的SMSi。在第一节中，我们将考察含有Zr-O-Zr桥的分子络合物作为氢气溢出到ZrO2表面的分子模型对CO2还原的电催化活性。第二部分利用表面金属有机化学的方法，在氧化锌和氧化锆表面直接合成了还原的锌和锆位，并用DRIFTS和TPR-MS考察了它们的反应活性。在第三部分中，我们将用核磁共振、紫外可见光谱、红外光谱和电子顺磁共振等手段考察了氧化锌和氧化锌与铜分子模型如Stryker试剂[HCu(PPh_3)]_6在有无CO_2存在下的反应活性。在最后阶段，我们将使用迄今为止开发的合成方法直接在已知催化剂的表面合成活性中心，这一策略被称为活性中心浓缩(ASE)。使用这种方法，可以通过简单的合成后处理来增加工作催化剂上的活性中心数量。