Direct synthesis (H₂ + O₂ → H₂O₂) could produce H₂O₂ (an environmentally benign oxidant) more cost-effectively and sustainably than anthraquinone oxidation, enabling broader use of H₂O₂ for industrial oxidations. We examine direct synthesis on Au_xPd₁ clusters to better understand the reasons for the high H₂O₂ selectivities of these materials. Steady-state H₂O₂ and H₂O formation rates were measured as functions of reactant pressure, temperature, and the protic or aprotic nature of the solvent. The analysis of these measurements indicates that H₂O₂ forms by consecutive proton-electron transfer steps on Au_xPd bimetallic catalysts. Among similarly sized Pd and Au_xPd₁ catalysts, increases in the Au:Pd ratio lead to simultaneous but unequal increases in the activation enthalpies ($\mathrm{\Delta }{H}^{‡}$) for both H₂O₂ and H₂O formation, which must result from significant electronic changes to Pd by Au. Detailed comparisons of these changes in $\mathrm{\Delta }{H}^{‡}$ for H₂O₂ and H₂O production to H₂O₂ selectivities provide compelling evidence that these electronic effects are primarily responsible for the high H₂O₂ selectivities commonly reported on AuPd bimetallic catalysts. Additionally, these results lack any clear trends that suggest ensemble effects contribute to the increased preference to form H₂O₂ on AuPd bimetallics within the ranges of compositions typically reported. These findings provide useful information on the significance of electronic effects in these Au_xPd₁ clusters and may guide the design of increasingly selective bimetallic catalysts.

直接合成（H ₂  + O ₂  →H ₂ O ₂）可以比蒽醌氧化更经济高效地生产H ₂ O ₂（一种环境友好的氧化剂），从而可以更广泛地使用H ₂ O ₂进行工业氧化。我们研究了在Au _x Pd ₁团簇上的直接合成，以更好地理解这些材料具有高H ₂ O ₂选择性的原因。稳态H ₂ O ₂和H ₂根据反应物压力，温度和溶剂的质子或非质子性质测量O形成速率。这些测量结果的分析表明，H ₂ O ₂是通过连续的质子电子转移步骤在Au _x Pd双金属催化剂上形成的。在尺寸相似的Pd和Au _x Pd ₁催化剂中，Au：Pd比的增加会导致活化焓同时但不相等地增加（$\mathrm{\Delta }{H}^{‡}$H ₂ O ₂和H ₂ O的生成），这必须归因于Au对Pd的显着电子变化。这些变化的详细比较$\mathrm{\Delta }{H}^{‡}$H ₂ O ₂和H ₂ O生成H ₂ O _2的选择性提供了令人信服的证据，这些电子效应是造成AuPd双金属催化剂普遍报道的高H ₂ O ₂选择性的主要原因。另外，这些结果缺乏任何明显的趋势，这些趋势表明集成效应有助于在通常报道的组成范围内在AuPd双金属上形成H ₂ O _2的偏好增加。这些发现为这些Au _x Pd ₁中电子效应的重要性提供了有用的信息。 簇，并可能指导越来越多的选择性双金属催化剂的设计。