A new catalyst design based on selective adsorption deposition method was developed to achieve high reaction performance in the direct synthesis of hydrogen peroxide. The activity of the unprecedented Pd/C catalyst was superior to that of the conventionally prepared Pd/C catalysts, and the initial H₂O₂ productivity and H₂ selectivity reached as high as 8606 mmol H₂O₂/g Pd.h and 95.1%, respectively. This excellent activity may result from the intrinsic structural and electronic features of the active sites, i.e., the extremely small and monodispersed Pd nanoparticles with a high Pd²⁺/Pd⁰ ratio, which were realized by combining the selective adsorption of metal precursor cations on a negatively charged activated carbon surface and the subsequent homogeneous surface deposition of palladium hydroxide by the hydroxide ions that are slowly generated upon urea decomposition. The catalytic activity was significantly affected by the oxygen groups of the activated carbon support. The carboxyl groups do not efficiently suppress the unfavorable H-OOH dissociation but rather accelerate the H₂O₂ hydrolysis by forming hydrogen bonds with H₂O₂. Moreover, a sharp decrease in the reaction rates of H₂O₂ hydrogenation and direct synthesis of H₂O₂ was observed with the increase in the number of carboxyl groups on the activated carbon surface. This loss of activity, as confirmed by acid treatment and olefin hydrogenation experiments, implies that the carboxyl groups in close proximity to the active sites have a detrimental effect by hindering or poisoning the active sites.

开发了一种基于选择性吸附沉积法的新型催化剂设计，以在直接合成过氧化氢中实现高反应性能。前所未有的Pd / C催化剂的活性优于常规制备的Pd / C催化剂，初始H ₂ O ₂产率和H ₂选择性高达8606 mmol H ₂ O ₂ / g Pd.h和。分别为95.1％。这种出色的活性可能归因于活性位点的固有结构和电子特征，即具有高Pd ²⁺ / Pd ⁰的极小且单分散的Pd纳米颗粒通过将金属前体阳离子的选择性吸附结合在带负电的活性炭表面上，以及随后通过脲分解时缓慢生成的氢氧根离子使氢氧化钯均匀沉积在表面上，可以实现上述比率。催化活性受到活性炭载体上氧原子的显着影响。羧基不能有效地抑制不利的H-OOH解离，而是通过与H ₂ O ₂形成氢键来加速H ₂ O ₂水解。此外，在H的反应速率的急剧下降₂ ö ₂ h的加氢和直接合成₂ ö随着活性炭表面上羧基数目的增加，观察到图₂。如酸处理和烯烃氢化实验所证实的，这种活性的丧失暗示着紧密靠近活性位的羧基具有阻碍或中毒活性位的有害作用。