Cardiff Catalysis Institute, School of Chemistry, Cardiff University, Main Building, Park Place, CF10 3AT, Cardiff, UK.
Chemphyschem. 2022 Jan 5;23(1):e202100583. doi: 10.1002/cphc.202100583. Epub 2021 Sep 30.
The acid-base character of oxide supports is crucial for catalytic reactions. In this work, the acid-base properties of five oxide surfaces common in heterogeneous catalysis were investigated and related to their interaction with monolignol compounds derived from lignin. We have used density functional theory simulations also to understand the role of the surfaces' hydroxylation state. The results show that moderate hydroxyl coverage on the amphoteric γ-Al O (110) slightly strengthens the oxy-compounds' adsorption due to an increase in Lewis acidity. Similarly, low hydroxyl coverage on the reducible TiO (101) enlarges its adsorption capacity by up to 42 % compared with its clean surface. The higher affinity is attributed to the more favourable interaction between the surface-OH groups and the aromatic rings. Overall, the results indicate that hydroxyl coverage enhances the amphoteric and reducible adsorption capacity towards aromatic species.
氧化物载体的酸碱特性对催化反应至关重要。在这项工作中，研究了 5 种在多相催化中常见的氧化物表面的酸碱性质，并将其与来源于木质素的单体木质醇化合物的相互作用联系起来。我们还使用密度泛函理论模拟来理解表面羟化状态的作用。结果表明，两性γ-Al2O3(110) 表面适度的羟基覆盖略微增强了氧合物的吸附，因为路易斯酸度增加。同样，在可还原的 TiO2(101) 表面上低的羟基覆盖度与清洁表面相比，将其吸附容量增加了高达 42%。这种更高的亲和力归因于表面-OH 基团和芳环之间更有利的相互作用。总的来说，结果表明羟基覆盖度增强了两性和可还原吸附对芳族物质的吸附能力。
