上海应用技术大学毛东森团队报道了，包封在UiO-67中Rh1,2-Rhn系簇的邻近性增强催化合成气转化为含氧物的过程。相关研究成果2024年3月20日发表于国际一流学术期刊《德国应用化学》。

在合成气转化中，在高含氧化合物选择性的前提下保持高转化率是重要的，但在Rh催化中是一个艰巨的挑战。单金属Rh催化剂提供较差的含氧化合物转化效率，并且一直致力于建造相邻的多金属场地。然而，在所报道的Rh基催化剂上，C₂+含氧化合物的单程产率大多<20%。

该研究中，研究人员构建了一种包封在UiO-67中的单金属Rh催化剂（Rh/UiO-67），该催化剂具有增强的双位点Rh1,2-Rhn系综接近性。出乎意料的是，该催化剂在由合成气合成含氧化合物方面表现出高效性，给出72.0%的高含氧化合物选择性和50.4%的显著CO转化率，并且C₂+含氧化合物的单程产率超过25%。

最先进的表征进一步揭示，Rh单原子/二聚体（Rh1,2）在限制在UiO-67纳米腔内的超小Rh团簇（Rhn）附近自发形成的团簇，在反应过程中动态提供相邻的Rh+-Rh0双位点，促进未解离的CHO物种向CHx物种的中继。因此，研究结果为设计高效的Rh催化剂开辟了一条新的途径，通过精确调节受限空间中双活性位点的整体和接近度，将合成气转化为含氧化合物。

附：英文原文

Title: Enhanced Proximity of Rh1,2-Rhn Ensembles Encaged in UiO-67 Boosting Catalytic Conversion of Syngas to Oxygenates

Author: Jun Yu, Tingting Liu, Qingqing Gu, Jia Wang, Ying Han, Gonghui Li, Qiangsheng Guo, Ye Gu, Xinping Wu, Xueqing Gong, Bing Yang, Dongsen Mao

Issue&Volume: 2024-03-20

Abstract: Maintaining high conversion under the premise of high oxygenates selectivity in syngas conversion is important but a formidable challenge in Rh catalysis. Monometallic Rh catalysts provide poor oxygenate conversion efficiency, and efforts have been focused on constructing adjacent polymetallic sites; however, the one-pass yields of C2+ oxygenates over the reported Rh-based catalysts were mostly <20%. In this study, we constructed a monometallic Rh catalyst encapsulated in UiO-67 (Rh/UiO-67) with enhanced proximity to dual-site Rh1,2-Rhn ensembles. Unexpectedly, this catalyst exhibited high efficacy for oxygenate synthesis from syngas, giving a high oxygenate selectivity of 72.0% with a remarkable CO conversion of 50.4%, and the one-pass yield of C2+ oxygenates exceeded 25%. The state-of-the-art characterizations further revealed the spontaneous formation of an ensemble of Rh single atoms/dimers (Rh1,2) in the proximity of ultrasmall Rh clusters (Rhn) confined within the nanocavity of UiO-67, providing adjacent Rh+-Rh0 dual sites dynamically during the reaction that promote the relay of the undissociated CHO species to the CHx species. Thus, our results open a new route for designing highly efficient Rh catalysts for the conversion of syngas to oxygenates by precisely tuning the ensemble and proximity of the dual active sites in a confined space.

DOI: 10.1002/anie.202401568

Source: https://onlinelibrary.wiley.com/doi/10.1002/anie.202401568