Noninvasive Nanoscopy Uncovers the Impact of the Hierarchical Porous Structure on the Catalytic Activity of Single Dealuminated Mordenite Crystals

نویسندگان

  • Alexey V Kubarev
  • Kris P F Janssen
  • Maarten B J Roeffaers
چکیده

Spatial restrictions around catalytic sites, provided by molecular-sized micropores, are beneficial to reaction selectivity but also inherently limit diffusion. The molecular transport can be enhanced by introducing meso- and macropores. However, the impact of this extraframework porosity on the local nanoscale reactivity is relatively unexplored. Herein we show that the area of enhanced reactivity in hierarchical zeolite, examined with super-resolution fluorescence microscopy, is spatially restricted to narrow zones around meso- and macropores, as observed with focused ion-beam-assisted scanning electron microscopy. This comparison indicates that reagent molecules efficiently reach catalytic active sites only in the micropores surrounding extraframework porosity and that extensive macroporosity does not warrant optimal reactivity distribution throughout a hierarchical porous zeolite.

برای دانلود رایگان متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Rationalizing Inter- and Intracrystal Heterogeneities in Dealuminated Acid Mordenite Zeolites by Stimulated Raman Scattering Microscopy Correlated with Super-resolution Fluorescence Microscopy

Dealuminated zeolites are widely used acid catalysts in research and the chemical industry. Bulk-level studies have revealed that the improved catalytic performance results from an enhanced molecular transport as well as from changes in the active sites. However, fully exploiting this information in rational catalyst design still requires insight in the intricate interplay between both. Here we...

متن کامل

Effect of various fuels on structure and photo-catalytic activity of TiO2 nano-crystalline prepared by microwave-assisted combustion method

Nano-crystalline TiO2 were synthesized by combustion method using metal nitrate solution and urea, glycin and citric acid fuels. Microwave irradiation was used as heating source. X-ray diffraction, scanning electron microscope as well as Fourier transform infrared spectroscopy were performed to characterize the obtained samples. X-ray diffraction patterns revealed that in the case of citric aci...

متن کامل

Hydroisomerization of n-Pentane over Pt/Mordenite Catalyst: Effect of Feed Composition and Process Conditions

The hydroisomerization of pure n-pentane over H-mordenite supported Pt-catalyst was investigated in a fixed bed reactor by changing reaction parameters such as temperature, pressure, and WHSV, as well as the H2/HC ratio. The maximum yield of isopentane over Pt/mordenite catalyst was achieved at 220 °C and a relatively low reaction pressure. To address the effect of feed composition on the catal...

متن کامل

CHARACTERIZATION OF HIGH-SILICA MORDENITE OBTAINED BY DIRECT SYNTHESIS

Three high-silica mordenite zeolites differing in SiO440, ratio were prepared by direct synthesis without using any template. The products Si02/A120, ratio is influenced by the starting gel composition. This ratio is increased upon ion-exchange with NH,Cl and subsequent calcination to prepare protonic mordenite. The protonic mordenites with Si02/A1203ra tios of 14.6,29.2 and 34.6 were chara...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

عنوان ژورنال:

دوره 7  شماره 

صفحات  -

تاریخ انتشار 2015