Hydroisomerization of Ethylbenzene on Mordenite-Based Bifunctional Catalysts with Different Platinum Contents

Abstract

A commercial Na-mordenite sample underwent ion exchange with HCl. The ion-exchanged sample was sequentially submitted to hydrothermal treatments at 823, 873 and 923 K, each followed by acid leaching of the extraframework alumina (EFAL) generated. Six mordenite samples, presenting different framework and extraframework compositions, were obtained. These samples were used to prepare bifunctional catalysts by mixing them with Pt/Al2O3 in different proportions. The generated samples presented distinct platinum contents and were tested in the hydroisomerization reaction of ethylbenzene. A maximum xylene selectivity at about 0.45 wt% of platinum was observed. Normally, the total activity increased as the platinum content increased; this effect was more pronounced in the samples which presented lower mesoporosity. The most dealuminated sample, which presented a high mesoporosity, did not show any change in activity with the increase in platinum content

From powder to technical body: the undervalued science of catalyst scale up

“…The unexpected loading of metals onto non-zeolitic phases due to a preferential interaction upon impregnation of the shaped catalyst or to the migration from the zeolite can alter the proximity of acid and metal functionalities, the metal dispersion, and the properties of the supported species. [111][112][113][114][115] Thus the catalytic performance can be adversely impacted through a poor choice of formulation.…”

“…This was attributed to the improved Pt dispersion over the support, which was approximately eight times higher than that evidenced when the platinum was directly impregnated onto the mordenite. 112 Upon impregnation of platinum onto K-LTL zeolite extrudates prepared with a basic MgO-doped alumina, a silica, or an acidic alumina binder, Kumar et al 113 evidenced distinct metal dispersions and catalytic performance. Higher platinum dispersion and aromatisation activity attained in the presence of the basic binder was attributed to a stronger metal-binder interaction due to the greater electronegativity of MgO.…”

Direct hydrothermal synthesis and stabilization of high-silica mordenite (Si∶Al = 25) using tetraethylammonium and fluoride ions

“…Mordenite (MOR) type zeolites, one of the high-silica zeolites, is an industrially important zeolite used in adsorptive separation and in catalysis such as isomerization, dewaxing and alkylation. [1][2][3] So, the preparation of high-silica MOR zeolite is still a rich field of research. The Si : Al ratio of MOR zeolite synthesized by conventional hydrothermal synthesis is 2-6; the Si : Al ratio is usually increased through removal of aluminium from the zeolite framework performed by steaming and/or by acid leaching.…”

Transformation of Indonesian Natural Zeolite into Analcime Phase under Hydrothermal Condition

“…60-70%) and the rest are clinoptilolites and amorphous quartz [1][2][3][4]. Zeolite is divided into hundreds of topology types [5], one type of zeolite topology, mordenite, that is often used as a catalyst in the industrial world [6]. It can be used as a catalyst in cracking reaction, isomerization [6] and combinations of hydrogenation cracking reaction [2,3].…”

“…Zeolite is divided into hundreds of topology types [5], one type of zeolite topology, mordenite, that is often used as a catalyst in the industrial world [6]. It can be used as a catalyst in cracking reaction, isomerization [6] and combinations of hydrogenation cracking reaction [2,3]. Natural zeolite from Klaten, Central Java contain mordenite and clinoptilolite with Si/Al ratio of 4.96 [7].…”