Atomic-scale engineering of indium oxide promotion by palladium for methanol production via CO2 hydrogenation
Atomic-scale engineering of indium oxide promotion by palladium for methanol production via CO2 hydrogenation
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DOI：
10.1038/s41467-019-11349-9
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发表时间：
2019-07-29
影响因子：
16.6
通讯作者：
Perez-Ramirez, Javier
中科院分区：
文献类型：
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作者：
Frei, Matthias S.;Mondelli, Cecilia;Perez-Ramirez, Javier
金属促进广泛应用于提高多相催化剂的性能以满足工业要求。尽管如此，生成和量化启动子形态的影响是非常具有挑战性的，该启动子形态专门引入了所需的特性并确保接近或容纳在活性位点内以及反应时的耐久性。最近，In2O3 被发现是一种高选择性和稳定的催化剂，用于从 CO2 生产绿色甲醇。通过钯（一种高效的 H-2 分解剂）促进活性增强，部分成功，因为钯纳米颗粒介导寄生反向水煤气变换反应，降低选择性，并与铟烧结或合金，限制金属利用率和鲁棒性。在这里，我们证明通过受控共沉淀达到的精确钯原子结构消除了这些限制。钯原子取代活性 In3O5 系综中的铟原子，吸引沉积在表面的额外钯原子，形成低核团簇，促进 H-2 活化并保持不变，从而实现 500 小时的创纪录生产率。
Metal promotion is broadly applied to enhance the performance of heterogeneous catalysts to fulfill industrial requirements. Still, generating and quantifying the effect of the promoter speciation that exclusively introduces desired properties and ensures proximity to or accommodation within the active site and durability upon reaction is very challenging. Recently, In2O3 was discovered as a highly selective and stable catalyst for green methanol production from CO2. Activity boosting by promotion with palladium, an efficient H-2-splitter, was partially successful since palladium nanoparticles mediate the parasitic reverse water-gas shift reaction, reducing selectivity, and sinter or alloy with indium, limiting metal utilization and robustness. Here, we show that the precise palladium atoms architecture reached by controlled co-precipitation eliminates these limitations. Palladium atoms replacing indium atoms in the active In3O5 ensemble attract additional palladium atoms deposited onto the surface forming low-nuclearity clusters, which foster H-2 activation and remain unaltered, enabling record productivities for 500 h.