Tian Shubo, Wang Ziyun, Gong Wanbing, Chen Wenxing, Feng Quanchen, Xu Qi, Chen Chun, Chen Chen, Peng Qing, Gu Lin, Zhao Huijun, Hu P, Wang Dingsheng, Li Yadong
Department of Chemistry , Tsinghua University , Beijing 100084 , China.
School of Chemistry and Chemical Engineering , The Queen's University of Belfast , Belfast BT9 5AG , U.K.
J Am Chem Soc. 2018 Sep 12;140(36):11161-11164. doi: 10.1021/jacs.8b06029. Epub 2018 Aug 31.
Hydrogenation and hydrodeoxygenation are significant and distinct approaches for the conversion of biomass and biomass-derived oxygenated chemicals into high value-added chemicals and fuels. However, it remains a great challenge to synthesize catalysts that simultaneously possess excellent hydrogenation and hydrodeoxygenation performance. Herein, we report a catalyst made of isolated single-atom Ru supported on mesoporous graphitic carbon nitride (Ru/mpg-CN), fabricated by a wet impregnation method. The as-prepared Ru/mpg-CN catalyst shows excellent hydrogenation and hydrodeoxygenation performance. First-principles calculations reveal that the Ru atom is mobilized, and the active site is induced by adsorption of the reactants. A systematic reaction mechanism is proposed, suggesting that vanillyl alcohol is the deoxygenation prohibited product, while 2-methoxy- p-cresol is the deoxygenation allowed product. Thus, the excellent selectivity for the hydrogenation or hydrodeoxygenation of vanillin at different temperatures results from switching between the two types of products.
加氢和加氢脱氧是将生物质及生物质衍生的含氧化合物转化为高附加值化学品和燃料的重要且不同的方法。然而，合成同时具备优异加氢和加氢脱氧性能的催化剂仍然是一个巨大的挑战。在此，我们报道了一种通过湿浸渍法制备的、由负载在介孔石墨相氮化碳上的孤立单原子钌（Ru/mpg-CN）制成的催化剂。所制备的Ru/mpg-CN催化剂表现出优异的加氢和加氢脱氧性能。第一性原理计算表明，钌原子被活化，且活性位点是由反应物的吸附诱导产生的。提出了一种系统的反应机理，表明香草醇是脱氧受阻产物，而2-甲氧基对甲酚是脱氧允许产物。因此，香草醛在不同温度下加氢或加氢脱氧的优异选择性源于这两种产物之间的切换。
