Due to their high toxicity and non-biodegradability, efficient reduction of nitroarenes to amines is of great practical importance, yet it still remains a significant challenge. Herein, we report PdO/PdO₂ nanoparticles uniformly supported on titanate nanotubes (PdO_x/TiNTs) for catalyzing the tandem dehydrogenation of sodium formate (SF) and hydrogenation of p-nitrophenol (PNP) to p-aminophenol (PAmP) under mild conditions. Notably, SF adsorption is mainly driven by the hydrogen bonding interactions between the H atom in SF and surface Pd sites, which factually makes the interface of PdO_x/TiNT–SF an effective platform for C–H activation. Meanwhile, it is also found that the efficiency of the hydrogenation reaction depends on the reduction rate of the nitro group to nitroso group, and the O atoms adjacent to Pd are considered as the essential sites that facilitate this process. On the basis of the above two effects, the PdO_x/TiNT catalyst shows unprecedented catalytic activity (turnover frequency, TOF, is 45.6 h⁻¹) and good selectivity (∼100%) during PNP reduction at room temperature. This work deepens our understanding on tandem catalytic (de)hydrogenation systems, and will benefit the design of heterogeneous catalysts for the production of industrially important chemicals.

中文翻译：

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吸附驱动的甲酸重整为氢化物，并在PdOx催化剂上将硝基苯酚串联氢化为胺

由于它们的高毒性和不可生物降解性，将硝基芳烃有效还原为胺具有重要的实际意义，但仍然是一个巨大的挑战。在这里，我们报告均匀地负载在钛酸酯纳米管上的PdO / PdO ₂纳米颗粒（PdO _x / TiNTs）在温和条件下催化甲酸钠（SF）的串联脱氢和对硝基苯酚（PNP）氢化为对氨基苯酚（PAmP） 。值得注意的是，SF的吸附主要由SF中的H原子与表面Pd位点之间的氢键相互作用驱动，这实际上使PdO _x的界面/ TiNT–SF是C–H激活的有效平台。同时，还发现氢化反应的效率取决于硝基还原为亚硝基的速率，并且与Pd相邻的O原子被认为是促进该过程的必要部位。基于以上两个效果，PdO _x / TiNT催化剂在室温下还原PNP时显示出空前的催化活性（周转频率TOF为45.6 h ^-1）和良好的选择性（〜100％）。这项工作加深了我们对串联催化（脱氢）系统的理解，并将有益于工业重要化学产品生产中非均相催化剂的设计。