Lu Xiaofei, Liu Yang, He Yurong, Kuhn Andrew N, Shih Pei-Chieh, Sun Cheng-Jun, Wen Xiaodong, Shi Chuan, Yang Hong
Department of Chemical and Biomolecular Engineering , University of Illinois at Urbana Champaign , 600 South Mathews Avenue , Urbana , Illinois 61801 , United States.
State Key Laboratory of Fine Chemicals, College of Chemistry , Dalian University of Technology , Dalian , Liaoning 116024 , P. R. China.
ACS Appl Mater Interfaces. 2019 Aug 7;11(31):27717-27726. doi: 10.1021/acsami.9b05645. Epub 2019 Jul 25.
The development of cost-effective catalysts with both high activity and selectivity for carbon-oxygen bond activation is a major challenge and has important ramifications for making value-added chemicals from carbon dioxide (CO). Herein, we present a one-step pyrolysis of metal organic frameworks that yields highly dispersed cobalt nanoparticles embedded in a carbon matrix which shows exceptional catalytic activity in the reverse water gas shift reaction. Incorporation of nitrogen into the carbon-based supports resulted in increased reaction activity and selectivity toward carbon monoxide (CO), likely because of the formation of a Mott-Schottky interface. At 300 °C and a high space velocity of 300 000 mL g h, the catalyst exhibited a CO conversion rate of 122 μmol g s, eight times higher than that of a reference Cu/ZnO/AlO catalyst. Our experimental and computational results suggest that nitrogen-doping lowers the energy barrier for the formation of formate intermediates (CO + H* → COOH* + ), in addition to the redox mechanism (CO + * → CO + O*). This enhancement is attributed to the efficient electron transfer at the cobalt-support interface, leading to higher hydrogenation activity and opening new avenues for the development of CO conversion technology.
开发对碳-氧键活化具有高活性和选择性的经济高效催化剂是一项重大挑战，对从二氧化碳（CO₂）制备增值化学品具有重要意义。在此，我们展示了一种金属有机框架的一步热解方法，该方法可生成高度分散在碳基质中的钴纳米颗粒，其在逆水煤气变换反应中表现出卓越的催化活性。将氮掺入碳基载体中可提高反应活性和对一氧化碳（CO）的选择性，这可能是由于形成了莫特-肖特基界面。在300℃和300000 mL g⁻¹ h⁻¹的高空速下，该催化剂的CO转化率为122 μmol g⁻¹ s⁻¹，比参考Cu/ZnO/Al₂O₃催化剂高八倍。我们的实验和计算结果表明，除了氧化还原机制（CO + * → CO* + O*）外，氮掺杂还降低了甲酸盐中间体形成的能垒（CO + H* → COOH* + *）。这种增强归因于钴-载体界面处的高效电子转移，从而导致更高的氢化活性，并为CO转化技术的发展开辟了新途径。
