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，是迄今为止用于车载氢存储和使用的最有前途的多相催化化学反应之一。其特别的优点主要是基于高的氢碳比（3：1），如果反应是高度CO2选择性的。为了实现这一目标，目前开发了一系列技术上也使用的并且已经充分表征的催化剂体系，包括铜-锌氧化物催化剂或基于钯的金属间化合物。然而，所使用的催化剂具有严重的缺点，即在催化剂活化时或甚至在反应期间易于严重烧结，或者在钯基金属间化合物的情况下，是结构上高度动态的体系。这通常妨碍催化活性中心的确定，导致高CO2选择性。在项目“甲醇蒸汽重整中寻求可靠的结构-性能关系”中讨论的铜-锆氧化物催化剂不仅表现出与所用材料相比具有高的CO2选择性和多种活性，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惰性，这简化了相关催化活性和选择性位点的测定。为了实现既定目标，需要突破催化剂制备和合成的新基础，以及能够在反应期间解析结构、形态和化学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。只有通过这种知识为基础的方法，一种新的催化剂材料，具有增强的活性和选择性，同时结构稳定的催化中心，最终结果，使建立可靠的结构-性能关系的甲醇水蒸气重整。

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.