'Surface Contrast' NMR Reveals Non-innocent Role of Support in Pd/CeO2Catalyzed Phenol Hydrogenation
'Surface Contrast' NMR Reveals Non-innocent Role of Support in Pd/CeO2Catalyzed Phenol Hydrogenation
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DOI：
10.1002/cctc.202000608
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发表时间：
2020-06-24
期刊：
影响因子：
4.5
通讯作者：
Venditti, Vincenzo
中科院分区：
文献类型：
--
作者：
Egner, Timothy K.;Naik, Pranjali;Venditti, Vincenzo
铈（CeO2）负载金属因其优异的氧化还原性能而被广泛用作催化剂。在这里，我们使用表面对比核磁共振方法研究了二氧化铈纳米粒子负载Pd对苯酚的加氢作用。我们发现苯酚与钯的刚性和平面结合是由小分子与二氧化铈的弱而高移动的结合介导的。有趣的是，虽然在混合物中加入磷酸盐不会干扰苯酚在Pd上的吸附，但它会破坏苯酚与二氧化铈的相互作用，并按比例降低催化转化率。我们的数据提供了强有力的实验证据，证明吸附质和铈之间的弱相互作用具有催化能力，并解释了Pd/CeO(2)在温和反应条件下还原转化的优异性能。
Ceria (CeO2)-supported metals are widely used as catalysts because of their exceptional redox properties. Here, we use surface contrast NMR methods to investigate the hydrogenation of phenol by Pd supported on ceria nanoparticles. We show that the rigid and planar binding of phenol to Pd is mediated by a weak and highly mobile association of the small molecule to ceria. Interestingly, while addition of phosphate to the mixture does not perturb the adsorption of phenol on Pd, it destabilizes its interaction with ceria and proportionally decreases the rate of catalytic conversion. Our data provide strong experimental evidence that weak interactions between adsorbate and ceria are catalytically competent and explain the exceptional performance of Pd/CeO(2)for reductive conversions under mild reaction conditions.