A tool for direct quantitative measurement of surface Brønsted acid sites of solids by H/D exchange using D2O
A tool for direct quantitative measurement of surface Brønsted acid sites of solids by H/D exchange using D2O
复制标题
使用 D2O 通过 H/D 交换直接定量测量固体表面布朗斯台德酸位点的工具
DOI：
10.1016/j.apcata.2005.04.013
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发表时间：
2005
影响因子：
5.5
通讯作者：
V. Keller
中科院分区：
文献类型：
--
作者：
G. Koehl;N. Keller;F. Garin;V. Keller
本文提出了一种直接定量测定固体表面布朗斯特酸性的方法，它是基于气态D_2O与酸性固体（-O-H酸表面基团的氢）之间的H/D交换动力学。该方法已应用于涵盖整个酸度范围的材料，从非常低的酸性材料（例如含碳固体）到高酸性材料（例如酸性氧化物或沸石）。使用具有已知酸度的良好表征的沸石进行校准，并允许使用通过质谱法直接测量交换的HDO分子信号给出的H/D实验交换曲线的积分表面来确定表面布朗斯台德酸位点的数量（以μmol/g计）。酸度力的测定与H/D交换第一步的速率常数直接相关。该方法允许在H/D实验曲线的去卷积之后，确定每种类型的表面布朗斯台德酸位点的数量和力。
A tool for direct and quantitative determination of surface Brønsted acidity of solids in terms of number, type and force based on quantitative H/D exchange kinetic between gaseous D2O and the acid solid, i.e. the hydron of the –O–H acid surface groups, has been developed. This method has been applied to materials covering the whole range of acidity, from very low acidic materials (e.g. carbonaceous solids) to high acidic materials (e.g. acidic oxides or zeolites). Calibration was performed using well-characterized zeolites with known acidities and allowed the number of surface Brønsted acid sites (in μmol/g) to be determined using the integrated surfaces of the H/D experimental exchange curve given by the direct measurement of the exchanged HDO molecule signal by mass spectrometry. The determination of the force of the acidity was directly linked to the rate constant of the first step of the H/D exchange. This method allows, after deconvolution of the H/D experimental curve, the number and force of each type of surface Brønsted acid sites to be determined.