红外光谱法研究表面溢出效应

采用红外光谱法, 利用重氢交换反应证明在Pt-NaY/HY体系有氢溢出(spillover)效应发生, 测量了100 ℃和50 ℃时的交换速率。发现在50 ℃时高频羟基的交换速率大于低频羟基。并对溢出机构进行了初步的讨论。

INVESTIGATION OF HYDROGEN SPILLOVER IN THE Pt-NaY/HY SYSTEM BY IR SPECTROSCOPY

The hydrogen spillover effect of Pt-NaY/HY system has been studied using the exchange reaction of deuterium with hydroxyl groups by IR spectroscopy. The Pt-NaY catalyst used was prepared by impregnation of NaY zeolite with chloroplatinic acid. HY zeolite was prepared by NH_4~+ exchange of the same NaY zeolite followed by thermal decomposition. About 12.5% Pt metal dispersion and a Pt particle size of about 9.0 nm were determined from H_2 Chemisorption data at 0 ℃.
The wafer of HY zeolite used in the IR cell was mixed with a small amount of the catalyst in such a way that the Pt catalyst dispersed only around the periphery of the wafer.
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