Selectivity Modulation of Encapsulated Palladium Nanoparticles by Zeolite Microenvironment for Biomass Catalytic Upgrading
Selectivity Modulation of Encapsulated Palladium Nanoparticles by Zeolite Microenvironment for Biomass Catalytic Upgrading
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DOI：
10.1021/acscatal.8b02276
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发表时间：
2018-09-01
期刊：
影响因子：
12.9
通讯作者：
Li, Landong
中科院分区：
文献类型：
--
作者：
Chai, Yuchao;Liu, Sihang;Li, Landong
沸石包裹的金属纳米颗粒作为一种特殊类型的催化剂，在活性、形状选择性和稳定性方面都比传统负载型催化剂有显著的优势。沸石微环境对包封纳米颗粒催化的选择性调节在理论上是可行的，但尚未得到解决。在这里，我们报道了亚纳米级钯在mfi型沸石中的原位包封，在糠醛加氢转化中表现出高活性和良好的稳定性，作为生物质升级的模型反应。值得注意的是，当硅石-1、Na-ZSM-5和H-ZSM-5分别作为钯纳米粒子的载体时，糠醛加氢转化可以得到不同的产物，如呋喃、糠醛醇和1,5-戊二醇。密度泛函理论计算和光谱研究表明，沸石微环境对糠醛的吸附和氢的活化都有显著影响，导致不同的反应途径。我们的工作提出了一个优雅的例子，通过调整沸石微环境的催化选择性调制封装的金属纳米颗粒。
Metal nanoparticles encapsulated in zeolite have been recently developed as a special type of catalyst that shows significant advantages in activity, shape-selectivity, and stability over conventional supported catalysts. The selectivity modulation of encapsulated nanoparticle catalysis by the zeolite microenvironment is theoretically possible but not addressed yet. Here, we report the in situ encapsulation of sub-nanometric palladium species within MFI-type zeolites, which exhibit high activity and good stability in the hydroconversion of furfural as a model reaction of biomass upgrading. Remarkably, different products, e.g., furan, furfural alcohol, and 1,5-pentanediol, from furfural hydroconversion can be obtained when silicalite-1, Na-ZSM-5, and H-ZSM-5 are employed as hosts of palladium nanoparticles, respectively. Density functional theory calculations and spectroscopy investigations reveal that both the adsorption of furfural and the activation of hydrogen are significantly affected by the zeolite microenvironment, leading to different reaction pathways. Our work presents an elegant example of catalytic selectivity modulation of encapsulated metal nanoparticles by tuning the zeolite microenvironment.