Datasets for Tuning the reactivity of carbon surfaces with oxygen-containing functional groups

Oxygen-containing carbons are promising supports and metal-free catalysts for many reactions. However, distinguishing the role of various oxygen functional groups and quantifying and tuning each functionality is still difficult. Here we investigate the role of Brønsted acidic oxygen-containing functional groups by synthesizing a diverse library of materials. By combining acid-catalyzed elimination probe chemistry, comprehensive surface characterizations (XPS, AP-XPS, TPDE-MS), 15N isotopically labeled acetonitrile adsorption coupled with magic-angle spinning nuclear magnetic resonance (MAS NMR), machine learning, and density-functional theory calculations (DFT), we demonstrate that phenolic (-OH) is the main acid site in gas-phase chemistries and unexpectedly Ar/R-carboxylic (-COOH) groups are much less acidic than -OH in the graphitized mesoporous carbon due to electron density delocalization induced by the aromatic rings of graphitic carbon. The methodology can identify acidic sites in oxygenated carbon materials in solid acid catalyst-driven chemistry.含氧碳材料在诸多反应中均具备作为载体与无金属催化剂的良好应用潜力。然而，区分各类含氧官能团的作用，并对每种官能团进行定量与调控仍颇具挑战。在此研究中，我们通过合成多样化的材料库，探究了布朗斯特酸性含氧官能团（Brønsted acidic oxygen-containing functional groups）的作用机制。通过结合酸催化消除探针反应化学、综合表面表征技术（X射线光电子能谱（XPS）、近常压X射线光电子能谱（AP-XPS）、程序升温脱附-质谱（TPDE-MS））、15N同位素标记乙腈吸附结合魔角旋转核磁共振（MAS NMR）、机器学习以及密度泛函理论计算（DFT），我们证实：酚羟基（-OH）是气相化学反应中的主要酸位点；出乎意料的是，由于石墨化碳的芳香环诱导产生的电子离域效应，在石墨化介孔碳中，芳基/烷基羧酸（-COOH）基团的酸性远弱于-OH。该方法可用于鉴定固体酸催化剂驱动的化学反应体系中含氧碳材料表面的酸性位点。