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首页> 外文期刊>The journal of physical chemistry, B. Condensed matter, materials, surfaces, interfaces & biophysical >Identification and measurements of strong Bronsted acid site in ultrastable Y (USY) zeolite
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Identification and measurements of strong Bronsted acid site in ultrastable Y (USY) zeolite

机译：超稳定Y（USY）沸石中强布朗斯台德酸位的鉴定和测量

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摘要

By using the IRMS-TPD method in which IR (infrared) and MS (mass spectroscopy) worked together, acid sites of USY (ultrastable Y) zeolite were studied. A new band of OH playing a role of Bronsted acid, was clearly detected on Na2H2-ethylenediaminetetraacetic acid (EDTA)-treated USY at 3595 cm(-1) during an elevation in temperature after the adsorption of ammonia. MS-measured TPD (temperature-programmed desorption) of NH3 and IR-measured TPD of the NH4+ cation coincided well to show that this zeolite consisted of the Bronsted acid sites. The MS-TPD profile at higher temperatures corresponded to the IR-TPD of the 3595-cm(-1) band, and therefore, this OH was identified as a strong acid site. From comparison between IR-TPD of OH and MS-TPD, numbers of three kinds of Bronsted OH (i.e., those in super and sodalite cages of a Y zeolite structure) and created strong Bronsted acid site were quantified. On the other hand, strength of the Bronsted acid site Delta H was determined individually by a simulation method, where the corrected IR-TPD of OH was simulated based on the proposed equation. Thus, a new strong Bronsted acid site was identified in the EDTA-treated USY, and the amount and strength was measured quantitatively.
机译：通过使用IR（红外）和MS（质谱）共同作用的IRMS-TPD方法，研究了USY（可超声Y）沸石的酸位。在氨气吸附后温度升高时，在3595 cm（-1）的Na2H2-乙二胺四乙酸（EDTA）处理的USY上清楚地检测到一条新的OH，起布朗斯台德酸的作用。 MS测量的NH3的TPD（程序升温脱附）与IR测量的NH4 +阳离子的TPD吻合得很好，表明该沸石由布朗斯台德酸性位点组成。较高温度下的MS-TPD谱图对应于3595-cm（-1）谱带的IR-TPD，因此，该OH被鉴定为强酸位点。通过比较OH的IR-TPD和MS-TPD，定量了三种布朗斯台德OH的数量（即，Y沸石结构的超级和方钠石笼中的那些）并产生了强布朗斯台德酸位。另一方面，通过模拟方法分别确定布朗斯台德酸位点ΔH的强度，其中基于所提出的方程式对经校正的OH的IR-TPD进行模拟。因此，在经EDTA处理的USY中确定了一个新的强布朗斯特酸位点，并对其含量和强度进行了定量测量。

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