Tailoring strong metal-support interactions (SMSIs) have been verified to become an efficient strategy for developing novel heterogeneous catalysts. Here, both TiO supports (anatase (A) and rutile (R)) were employed to prepare the Pd/TiO catalysts and strongly titania-crystal-phase-dependent Pd-TiO SMSIs and catalysis in CO hydrogenation were observed. A-TiO is more facile to undergo Pd-TiO SMSIs than R-TiO, which could be relevant to better reducibility over calcined Pd/A-TiOC catalyst. Catalytic performance of the Pd/TiO-R (reduced) catalysts in CO hydrogenation are sensitive to the Pd-TiO structures, among which the Pd nanoparticles mostly encapsulated by TiO overlayers over Pd/A-TiO-R catalyst with more prominent SMSIs is more intrinsically active. This could be ascribed to both stronger H-spillover and hydrogenation property and better CO activation capacity over Pd/A-TiO-R catalyst. However, its catalytic activity is seriously restricted by the number of intrinsically active sites due to less exposed Pd atoms to block H activation sites. These results clearly demonstrate the crystal-phase engineering as an efficient strategy to tailor the SMSIs for developing improved heterogeneous catalysts.

中文翻译：

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二氧化钛晶相工程强金属-载体相互作用和二氧化碳加氢催化

定制强金属-载体相互作用（SMSI）已被证实成为开发新型多相催化剂的有效策略。在这里，采用两种 TiO2 载体（锐钛矿 (A) 和金红石 (R)）来制备 Pd/TiO2 催化剂，并观察到强二氧化钛晶相依赖性的 Pd-TiO2 SMSI 和 CO 加氢催化作用。 A-TiO 比 R-TiO 更容易经历 Pd-TiO SMSI，这可能与煅烧 Pd/A-TiOC 催化剂相比具有更好的还原性有关。 Pd/TiO-R（还原）催化剂在CO加氢中的催化性能对Pd-TiO结构敏感，其中Pd纳米粒子大多被TiO覆盖层包裹在Pd/A-TiO-R催化剂上，SMSI更突出。本质上活跃。这可以归因于 Pd/A-TiO-R 催化剂具有更强的 H 溢出和加氢性能以及更好的 CO 活化能力。然而，由于较少暴露的 Pd 原子来阻止 H 活化位点，其催化活性受到固有活性位点数量的严重限制。这些结果清楚地表明，晶相工程是定制 SMSI 以开发改进的多相催化剂的有效策略。