Department of Chemical Engineering, Columbia University, New York, NY, 10027, USA.
Department of Chemical Engineering, University of South Carolina, Columbia, SC, 29208, USA.
Nat Commun. 2018 Nov 5;9(1):4612. doi: 10.1038/s41467-018-07047-7.
The selective hydrodeoxygenation (HDO) reaction is desirable to convert glycerol into various value-added products by breaking different numbers of C-O bonds while maintaining C-C bonds. Here we combine experimental and density functional theory (DFT) results to reveal that the Cu modifier can significantly reduce the oxophilicity of the molybdenum carbide (MoC) surface and change the product distribution. The MoC surface is active for breaking all C-O bonds to produce propylene. As the Cu coverage increases to 0.5 monolayer (ML), the Cu/MoC surface shows activity towards breaking two C-O bonds and forming ally-alcohol and propanal. As the Cu coverage further increases, the Cu/MoC surface cleaves one C-O bond to form acetol. DFT calculations reveal that the MoC surface, Cu-Mo interface, and Cu surface are distinct sites for the production of propylene, ally-alcohol, and acetol, respectively. This study explores the feasibility of tuning the glycerol HDO selectivity by modifying the surface oxophilicity.
选择性加氢脱氧（HDO）反应是将甘油转化为各种增值产品的理想方法，它可以在保持 C-C 键的同时，断裂不同数量的 C-O 键。在这里，我们结合实验和密度泛函理论（DFT）的结果，揭示了 Cu 修饰剂可以显著降低碳化钼（MoC）表面的亲氧性并改变产物分布。MoC 表面对于断裂所有 C-O 键以生成丙烯具有活性。随着 Cu 覆盖率增加到 0.5 单层（ML），Cu/MoC 表面对断裂两个 C-O 键并形成烯丙醇和丙醛表现出活性。随着 Cu 覆盖率的进一步增加，Cu/MoC 表面将一个 C-O 键断裂形成乙酰醇。DFT 计算表明，MoC 表面、Cu-Mo 界面和 Cu 表面分别是生成丙烯、烯丙醇和乙酰醇的不同活性位。本研究探索了通过修饰表面亲氧性来调节甘油 HDO 选择性的可行性。
