Department of Chemical Engineering, University of Pittsburgh, Pittsburgh, PA 15261, USA.
Nanoscale. 2018 Feb 22;10(8):4004-4009. doi: 10.1039/c7nr08678d.
Rational design of catalysts for selective conversion of alcohols to olefins is key since product selectivity remains an issue due to competing etherification reactions. Using first principles calculations and chemical rules, we designed novel metal-oxide-protected metal nanoclusters (MXO, with M = Cu, Ag, and Au and X = Al, Ga, and In) exhibiting strong Lewis acid sites on their surface, active for the selective formation of olefins from alcohols. These symmetrical nanocatalysts, due to their curvature, show unfavorable etherification chemistries, while favoring the olefin production. Furthermore, we determined that water removal and regeneration of the nanocatalysts is more feasible compared to the equivalent strong acid sites on solid acids used for alcohol dehydration. Our results demonstrate an exceptional stability of these new nanostructures with the most energetically favorable being Cu-based. Thus, the high selectivity and stability of these in-silico-predicted novel nanoclusters (e.g. CuAlO) make them attractive catalysts for the selective dehydration of alcohols to olefins.
设计用于选择性醇制烯烃的催化剂是关键，因为由于竞争醚化反应，产物选择性仍然是一个问题。我们使用第一性原理计算和化学规则设计了新型的金属氧化物保护的金属纳米团簇（MXO，其中 M = Cu、Ag 和 Au，X = Al、Ga 和 In），其表面具有强路易斯酸位，可用于从醇选择性形成烯烃。这些对称的纳米催化剂由于其曲率，表现出不利的醚化化学性质，而有利于烯烃的生成。此外，我们确定与用于醇脱水的固体酸上的等效强酸位相比，纳米催化剂的脱水性和再生性更为可行。我们的结果表明这些新型纳米结构具有出色的稳定性，其中最具能量优势的是基于 Cu 的纳米结构。因此，这些通过计算机预测的新型纳米团簇（例如 CuAlO）具有高选择性和稳定性，使其成为醇脱水制烯烃的有吸引力的催化剂。
