摘要
最近的研究表明,磷酸钛作为新的固体酸催化剂、颜料和无机离子交换剂的性能比目前广泛应用的二氧化钛更为优越.它的优越性能可能与其表面酸性质有密切关系.但是,有关磷酸钛表面酸性和表面基团的研究目前尚未见报导,仅见到用Benes法测定磷酸钛表面酸强度分布的报导,但是Benesi法无法确定酸位的性质和表面基团.本文用红外光谱法和Benesi法研究了磷酸钛的表面酸性。
The surface acid properties of titanium phosphate were studied by IR spectroscopy and n-butylamine titration. The bands at 3670 and 3400 cm-1 originate from the isolated phosphorus-hydroxyl groups and hydrogen bonded titanium-hydroxyl groups on the surface respectively. IR spectra of pyridine adsorbed on titanium phosphate show that there are Bronsted and Lewis acid sites on the surface and they are attributable to the isolated phosphorus-hydroxyl groups and the titanium ions incompletely coordinated respectively. The results of n-butylamine titration of the sample indicate that the amount of acid sites on the surface is 0.1mmol/g and the acid sites consists of strong and weak acid sites. The phosphorus-hydroxyl groups and the titanium ions incompletely coordinated are responsible for the strong and weak acid sites respectively.
