Advances in the synthetic control of surface nanostructures could improve the activity, selectivity and stability of heterogeneous catalysts. Here, we present a technique for the controlled deposition of TiO₂ overcoats based on non-hydrolytic sol-gel chemistry. Continuous injection of Ti(ⁱPrO)₄ and TiCl₄ mixtures led to the formation of conformal TiO₂ overcoats with a growth rate of 0.4 nm/injected monolayer on several materials including high surface area SBA-15. Deposition of TiO₂ on SBA-15 generated medium-strength Lewis acid sites, which catalyzed 1-phenylethanol dehydration at high selectivities and decreased deactivation rates compared to typically used HZSM-5. When supported metal nanoparticles were similarly overcoated, the intimate contact between the metal and acid sites at the support-overcoat interface significantly increased propylcyclohexane selectivity during the deoxygenation of lignin-derived propyl guaiacol (89% at 90% conversion compared to 30% for the uncoated catalyst). For both materials, the surface reactivity could be tuned with the overcoat thickness.

表面纳米结构的合成控制方面的进展可以提高非均相催化剂的活性，选择性和稳定性。在这里，我们介绍了一种基于非水解溶胶-凝胶化学方法可控地沉积TiO ₂外涂层的技术。连续注入Ti（ⁱ PrO）₄和TiCl ₄混合物导致在包括高表面积SBA-15在内的多种材料上以0.4 nm /注入单层的生长速率形成了保形TiO ₂涂层。TiO _2的沉积与通常使用的HZSM-5相比，在SBA-15上生成的中等强度路易斯酸位点可催化1-苯基乙醇脱水，选择性高，失活速率降低。当对载体金属纳米颗粒进行类似的包覆时，在木质素衍生的丙基愈创木酚脱氧过程中，载体与外涂层界面处的金属和酸位点之间的紧密接触会显着提高丙基环己烷的选择性（90％的转化率为89％，而未包覆的为30％催化剂）。对于这两种材料，可以根据外涂层的厚度调整表面反应性。