Catalysts containing Pt nanoparticles and reducible transition-metal oxides (WO_x, NbO_x, TiO_x) exhibit remarkable selectivity to aromatic products in hydrodeoxygenation (HDO) reactions for biomass valorization, contrasting the undesired aromatic hydrogenation typically observed for metal catalysts. However, the active site(s) responsible for the high selectivity remains elusive. Here, theoretical and experimental analyses are combined to explain the observed HDO reactivity by interrogating the organization of reduced WO_x domains on Pt surfaces at sub-monolayer coverage. The SurfGraph algorithm is used to develop model structures that capture the configurational space (∼1000 configurations) for density functional theory (DFT) calculations of a W₃O₇ trimer on stepped Pt surfaces. Machine-learning models trained on the DFT calculations identify the preferential occupation of well-coordinated Pt sites (≥8 Pt coordination number) by WO_x and structural features governing WO_x–Pt stability. WO_x/Pt/SiO₂ catalysts are synthesized with varying W loadings to test the theoretical predictions and relate them to HDO reactivity. Spectroscopy- and microscopy-based catalyst characterizations identify the dynamic and preferential decoration of well-coordinated sites on Pt nanoparticles by reduced WO_x species, consistent with theoretical predictions. The catalytic consequences of this preferential decoration on the HDO of a lignin model compound, dihydroeugenol, are clarified. The effect of WO_x decoration on Pt nanoparticles for HDO involves WO_x inhibition of aromatic ring hydrogenation by preferentially blocking well-coordinated Pt sites. The identification of preferential decoration on specific sites of late-transition-metal surfaces by reducible metal oxides provides a new perspective for understanding and controlling metal–support interactions in heterogeneous catalysis.

中文翻译：

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WOx 动态优先修饰 Pt 催化剂表面对加氢脱氧反应的影响


含有 Pt 纳米颗粒和可还原过渡金属氧化物（WO _x 、 NbO _x 、 TiO _x ）的催化剂在加氢脱氧（HDO）反应中对芳香族产物表现出显着的选择性对于生物质增值，与通常在金属催化剂中观察到的不良芳烃氢化形成对比。然而，负责高选择性的活性位点仍然难以捉摸。在这里，理论和实验分析相结合，通过询问亚单层覆盖的 Pt 表面上还原的 WO _x 域的组织来解释观察到的 HDO 反应性。 SurfGraph 算法用于开发模型结构，捕获配置空间（∼1000 个配置），用于阶梯式 Pt 表面上 W ₃ O ₇ 三聚体的密度泛函理论 (DFT) 计算。经过 DFT 计算训练的机器学习模型确定了 WO _x 优先占据良好配位的 Pt 位点（≥8 Pt 配位数）以及控制 WO _x 的结构特征 - Pt 稳定性。合成了具有不同 W 负载量的 WO _x /Pt/SiO ₂ 催化剂，以测试理论预测并将其与 HDO 反应性联系起来。基于光谱学和显微镜的催化剂表征确定了还原的 WO _x 物质对 Pt 纳米粒子上协调良好的位点的动态和优先修饰，与理论预测一致。阐明了这种优先修饰对木质素模型化合物二氢丁子香酚的 HDO 的催化作用。 WO _x 修饰对用于 HDO 的 Pt 纳米粒子的影响涉及 WO _x 通过优先阻断良好配位的 Pt 位点来抑制芳环氢化。 通过可还原金属氧化物对后过渡金属表面特定位点的优先修饰进行识别，为理解和控制多相催化中金属-载体相互作用提供了新的视角。