you can see in this paper *It is also observed that the addition of WO3 to γ-Al2O3 up to 3 % WA increases the surface area due to doping effect and the creation of new pores due to an effective diffusion of WO3 species in the γ-Al2O3 support*.
http://link.springer.com/article/10.1007/s00706-015-1649-7
Good luck
To increase surface area of an adsorbent, you can do by chemical activation or thermal activation. H3PO4 used for chemical activation. Microwave irradiation used for thermal activation. Microwave exposure time plays a vital role in pore structure of adsorbent.
Two effects may be expected: either you decrease the surface area as the added catalyst blocks the pores of the substrate, or you increase the surface area because the dispersion state of the catalyst is quite high. In your case, you used a nanocatalyst so that not only the pores of the support were not clogged but the particles you added were so small that their surface area was (much) higher than that of the support, from where the global increase you observed.
Nothing surprising, finally.
Alain
Hello Alain,
Thank you ver much for your response. I appreciate your help.
Excuse me , could you provide me with an article as a reference about this point?
Best regards
I cannot really suggest some precise papers. These are situations that I personally met. The most frequent situation is, however, the decrease of surface area, not only due to pore clogging but also to the mass increase: even if the pores remain fully open and unblocked, loading several % of metal nanoparticles increases the mass of material so that the number of m2/g decreases accordingly. This, I published already, but not the case wherein the nanoparticles had so high surface area by themselves that adding them made the overall area increase.
Alain
Have seen the same effect as Mr Celzard mention, the sureface decreases proportionally more than the mass change will account for. Most likely pore blocking.
would you please tell me is it possible to calculat the specific area using BET of a rods of graphene oxides decorated by Fe2O3? if we can, what's the ( m/g ) taht i should know to start the characterization?.
Greetings
Does structure of metal oxide affect the surface area?
In my case, I supported different metal oxide on a microporous support. According to XRD, deposition of different metal oxides has different structure such as cubic, hexagonal, orthorhombic etc. on the microporous support. The BET surface of the microprous support was decreased differently after disposition of different metal oxides. Can we say that the decrease in BET surface area of the microporous support was due to metal oxide structure? Like hexagonal structure caused less decrease in BET surface area than cubic structure.
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