近日，中国科学院大连化学物理研究所刘中民团队实现了分子筛框架锚定的Rh- (O-Zn)_x乙烯氢甲酰化位点的构建。相关论文于2025年9月10日发表在《美国化学会志》上。

沸石限制的Rh基催化剂已成为烯烃加氢甲酰化的有前景的非均相候选者。然而，它们面临着反应物和产物诱导的Rh浸出和聚集的挑战。

研究组设计了沸石骨架锚定的Rh^δ+-（O-Zn）_x位点，并表明其对气相乙烯氢甲酰化具有显著的活性和稳定性。通过将Rh和Zn物种共包封到Silicalite-1沸石中合成了双金属催化剂，在加氢甲酰化过程的诱导期，通过可移动的Rh羰基物种与骨架≡SiOZn-O（H）之间的相互作用，原位构建了Rh^δ+-（O-Zn）_x位点。Zn/Rh摩尔比的变化显著影响Rh的分散性和高活性Rh^δ+的比例。 

最优的0.2Rh@Zn₃-S-1催化剂在363 K下的丙醛周转频率高达148 h^-1，在40小时的测试中没有失活迹象。相比之下，不含锌0.2Rh@S-1由于Rh聚集而遭受快速失活。原位傅里叶变换红外光谱（FTIR）表明，丙醛从Rh到Zn-O的转移-解吸有助于Rh^δ+-（O-Zn）_x结构构建过程中Rh的再分散。此外，观察到的HRh（CO）₂物种以及催化剂上Rh^δ+-丙酰基中间体的富集表明，酰基物种的氢化是乙烯加氢甲酰化的限速步骤，这进一步得到了动力学分析的支持。

研究组提出了一种新的策略，使用沸石锚定的金属物种作为Rh^δ+中心的无机配体，设计稳定有效的气相乙烯氢甲酰化催化剂，并深入了解了双金属位点上发生的氢甲酰基化机制。

附：英文原文

Title: Construction of Zeolite Framework-Anchored Rh–(O–Zn)x Sites for Ethylene Hydroformylation

Author: Haocheng Hu, Wenhao Cui, Mingbin Gao, Linying Wang, Shiping Liu, Liang Qi, Wenfu Yan, Peng Tian, Zhongmin Liu

Issue&Volume: September 10, 2025

Abstract: Zeolite-confined Rh-based catalysts have emerged as promising heterogeneous candidates for olefin hydroformylation. However, they face challenges of reactant- and product-induced Rh leaching and aggregation. Herein, zeolite framework-anchored Rhδ+–(O–Zn)x sites were designed and are shown to have remarkable activity and stability for gas-phase ethylene hydroformylation. The bimetallic catalysts were synthesized by coencapsulating Rh and Zn species into Silicalite-1 zeolite, and the Rhδ+–(O–Zn)x sites were in situ constructed during the induction period of the hydroformylation process through the interaction between mobile Rh-carbonyl species and framework ≡SiOZn–O(H). The change of the Zn/Rh molar ratio significantly affects the dispersion of Rh and the proportion of highly active Rhδ+. The optimal 0.2Rh@Zn3-S-1 catalyst achieves a propanal turnover frequency as high as 148 h–1 at 363 K and shows no sign of deactivation during the 40 h test. In contrast, zinc-free 0.2Rh@S-1 suffers rapid deactivation due to Rh aggregation. In situ Fourier transform infrared (FTIR) spectroscopy reveals that the transfer desorption of propanal from Rh to Zn–O contributes to the redispersion of Rh during the construction of Rhδ+–(O–Zn)x structures. Moreover, the observed HRh(CO)2 species together with the enrichment of Rhδ+-propionyl intermediates on the catalyst indicates that the hydrogenation of acyl species is the rate-limiting step of ethylene hydroformylation, which is further supported by kinetic analysis. This study presents a new strategy for designing stable and efficient gas-phase ethylene hydroformylation catalysts using zeolite-anchored metal species as inorganic ligands for Rhδ+ centers and provides insights into the hydroformylation mechanism occurring on the bimetallic sites.

DOI: 10.1021/jacs.5c07586

Source: https://pubs.acs.org/doi/abs/10.1021/jacs.5c07586