The Quest to Reliable Structure-Property Relationships in Methanol Steam Reforming

甲醇蒸汽重整，即由甲醇和水生成氢气和二氧化碳，是迄今为止最有前途的非均相催化化学反应之一，用于机载氢储存和使用。它的特殊优势主要是基于高氢碳比（3:1），如果反应是高二氧化碳选择性的。为了实现这一目标，目前正在开发一系列技术上已经使用并且已经很好表征的催化剂系统，包括铜-锌氧化物催化剂或钯基金属间化合物。然而，所使用的催化剂存在严重的缺陷，要么在催化剂活化时甚至在反应过程中容易严重烧结，要么在钯基金属间化合物的情况下，是结构上高度动态的系统。这通常阻碍了催化活性中心的测定，从而导致高CO2选择性。在“探索甲醇蒸汽重整中可靠的结构-性能关系”项目中讨论的铜-氧化锆催化剂与使用的材料相比，不仅具有高的CO2选择性，同时具有多种活性，而且作为一个特殊的优势，还提供了更高的结构和化学稳定性。这主要是由于氧化锆固有的化学不活性，这简化了相关催化活性和选择位点的测定。为了达到既定的目标，需要打破催化剂制备和合成的新基础，以及能够解决反应过程中结构、形态和化学性质的专用结构和化学表征技术，以优化铜和氧化锆两种组分的化学性质。只有通过这种基于知识的方法，才能最终得到一种活性和选择性增强，同时催化中心结构稳定的新型催化剂材料，从而为甲醇蒸汽重整建立可靠的结构-性能关系。

Methanol steam reforming, that is, the generation of hydrogen and carbon dioxide from methanol and water is to date one of the most promising heterogeneously catalyzed chemical reactions for on-board hydrogen storage and use. Its particular advantage is mainly based on the high hydrogen-to-carbon ratio (3:1), if the reaction is led highly CO2-selective. To achieve this goal, at the moment a range of also technologically used and already well-characterized catalyst systems are exploited, including copper-zinc oxide catalysts or intermetallic compounds on palladium basis. However, the used catalysts suffer from the severe drawbacks of either being prone to serious sintering upon catalyst activation or even during reaction, or, in the case of palladium-based intermetallic compounds, being structurally highly dynamic systems. This typically hampers the determination of the catalytically active centers leading to high CO2 selectivity. The copper-zirconium oxide catalysts discussed in the project "The Quest to Reliable Structure-Property Relationships in Methanol Steam Reforming" exhibit not only a high CO2 selectivity with at the same time multiple activities compared to used materials, but as a particular advantage also offer also an increased structural and chemical stability. This is mainly due to the inherent chemical inactivity of zirconium oxide, which simplifies the determination of the associated catalytically active and selective sites. To reach the set goal, new grounds of catalyst preparation and synthesis need to be broken as well as dedicated structural and chemical characterization techniques capable of resolving structure, morphology and chemistry during reaction applied to optimize the chemistry of the two components copper and zirconium oxide. Only by this knowledge-based approach, a new catalyst material with enhanced activity and selectivity with at the same time structurally stable catalytic center finally results, enabling setting-up reliable structure-property relationships for methanol steam reforming.