论文部分内容阅读
用正丁胺作为吸附质,考察了在不同交换度的NaCaY和NaNH_4Y沸石上的程序升温脱,附。正丁胺在NaY上的TPD图谱基本上和吡啶的相同,不同处是在350℃以上尚有一小峰包(峰Ⅲ)。NaY中Na~+离子经Ca~(2+)离子交换后,峰Ⅱ向低温处转移,而肩膀峰(峰Ⅰ)亦渐趋消失。在NH_4~+交换后的NaHY分子筛上,除峰Ⅱ、峰Ⅰ有与CaNaY相似的变化外,在高温区,峰Ⅲ前另出一峰Ⅳ,它随NH_4~+离子交换度的增加而增大,同时向高温区位移,至NH_4~+交换度为90％时,峰Ⅲ和峰Ⅳ重合。Ca~(2+)或NH_4~+交换的NaY分子筛,其正丁胺的TPD图谱都具同一特征,即在高温区出现一新峰,表明NaY经钙或类似的其他离子交换后产生新的酸性吸附中心。经色谱鉴定,脱附产物只有正丁胺,其总吸附量随交换度增加而递减,表明正丁胺在Na~+离子上的吸附较强。
Using n-butylamine as adsorbate, the temperature-programmed desorption on NaCaY and NaNH 4 Y zeolites with different exchange degrees was investigated. The TPD spectrum of n-butylamine on NaY is basically the same as that of pyridine, with the exception that there is a small peak at 350 ° C (peak III). After Na ~ + ions were exchanged by Ca ~ (2+) ion in NaY, the peak Ⅱ shifted to low temperature, while the shoulder peak (peak Ⅰ) disappeared gradually. On the NaHY zeolite after NH 4 + exchange, except for the peaks Ⅱ and Ⅰ, there is a similar change with CaNaY. In the high temperature region, another peak IV appears before the peak III, which increases with the increase of NH 4 + ion exchange rate , While the displacement to the high temperature, NH_4 ~ + exchange rate of 90%, the peak Ⅲ and peak Ⅳ coincide. The TPD patterns of n-butylamine in Na ~ + exchanged with Ca ~ (2+) or NH_4 ~ + all have the same feature that a new peak appears in the high temperature region, indicating that NaY is exchanged by other ions such as calcium or similar Acid adsorption center. The chromatographic identification, desorption product only n-butylamine, the total amount of adsorption decreases with the degree of exchange decreases, indicating n-butylamine adsorption on the Na ~ + ions stronger.