Metal-Organic Frameworks Encaged Ru Single Atoms for Rapid Acetylene Harvest and Activation in Hydrochlorination.
Metal-Organic Frameworks Encaged Ru Single Atoms for Rapid Acetylene Harvest and Activation in Hydrochlorination.
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DOI：
10.1021/acsami.3c01983
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发表时间：
2023-05
影响因子：
9.5
通讯作者：
Yurui Fan;Zhisong Liu;Songyuan Sun;Wenjun Huang;Lei Ma;Zan Qu;N. Yan;Haomiao Xu
中科院分区：
文献类型：
--
作者：
Yurui Fan;Zhisong Liu;Songyuan Sun;Wenjun Huang;Lei Ma;Zan Qu;N. Yan;Haomiao Xu
钌 (Ru) 基催化剂一直是氯乙烯单体 (VCM) 生产氢氯化反应的候选材料，但它们受到乙炔 (C2H2) 高效利用的限制。 HCl 的强吸附性能会使 Ru 活性位点失活，导致 C2H2 吸附较弱，活化动力学缓慢。在此，我们设计了一种采用金属有机框架（MOF）包裹Ru单原子的通道来实现C2H2的快速吸附和活化。低Ru（∼0.5 wt%）单原子催化剂（命名为Ru-NC@MIL）是通过氢键纳米陷阱（C2H2和羧酸根/呋喃环之间的H-C≡C-Hδ+···Oδ-相互作用）组装而成。结果证实，C2H2 能够以垂直于通道的最佳模式轻松进入包封通道，势能为 42.3 kJ/mol。通过将碳-碳三键 (C≡C) 长度拉伸至 1.212 Å，收获的 C2H2 分子可以快速传递到 Ru-N4 活性位点进行激活。这种策略保证了>99%的C2H2转化效率和>99%的VCM选择性。此外，还实现了稳定的长期（>150 h）催化，具有高效率（∼0.85 kgvcm/h/kgcat.）和低失活常数（0.001 h-1）。这项工作为精确C2H2吸附和活化提供了创新策略，并为设计多功能钌基催化剂提供了指导。
Ruthenium (Ru)-based catalysts have been candidates in hydrochlorination for vinyl chloride monomer (VCM) production, yet they are limited by efficient acetylene (C2H2) utilization. The strong adsorption performance of HCl can deactivate Ru active sites which resulted in weak C2H2 adsorption and slow activation kinetics. Herein, we designed a channel that employed metal-organic framework (MOF)-encaged Ru single atoms to achieve rapid adsorption and activation of C2H2. Low-Ru (∼0.5 wt %) single-atom catalysts (named Ru-NC@MIL) were assembled by hydrogen-bonding nanotraps (the H-C≡C-Hδ+···Oδ- interactions between C2H2 and carboxylate groups/furan rings). Results confirmed that C2H2 could easily enter the encapsulation channels in an optimal mode perpendicular to the channel with a potential energy of 42.3 kJ/mol. The harvested C2H2 molecules can be quickly passed to Ru-N4 active sites for activation by stretching the length of carbon-carbon triple bonds (C≡C) to 1.212 Å. Such a strategy guaranteed >99% C2H2 conversion efficiency and >99% VCM selectivity. Moreover, a stable long-term (>150 h) catalysis with high efficiency (∼0.85 kgvcm/h/kgcat.) and a low deactivation constant (0.001 h-1) was also achieved. This work provides an innovative strategy for precise C2H2 adsorption and activation and guidance for designing multi-functional Ru-based catalysts.