NDA@SZTAKI

MOLYBDENUM DOPED CARBON AEROGELS WITH CATALYTIC POTENTIAL

Nagy, BalĂĄzs

Ábrahåm, Dåniel

Dobos, GĂĄbor

MadarĂĄsz, JĂĄnos

OnyestyĂĄk, GyĂśrgy

SĂĄfrĂĄn, GyĂśrgy

Geissler, Erik

LĂĄszlĂł, Krisztina

Elsevier

2014

QD02 Physical chemistry / fizikai kĂŠmia

QD04 Organic chemistry / szerves kĂŠmia

Mo-doped carbon aerogels were obtained in the polycondensation reaction of aqueous
resorcinol and formaldehyde by adding Mo-salt at two different stages of the synthesis: i) to
the initial sol; ii) by incipient wetting impregnation of the supercritically dried polymer gel.
Molybdenum added during the polymerization yielded a more compact gel structure with
practically no mesoporosity. With post-impregnation, by contrast, mesopores of diameter 3-15
nm were generated. Carbonization appreciably enhanced the microporous character of both
samples, but in the mesopore range their pore size distribution was conserved. The Mocontent
of the samples was also different: Mo was lost during the solvent exchange before the
supercritical drying (i.e., the Mo failed to bind chemically to the polymer matrix). The
residual Mo congregated into 25-60 nm bulk clusters of Îą-Mo2C. In the other carbon aerogel,
finely dispersed ι-Mo2C and Ρ-Mo3C2 crystals formed, of size 8-20 nm. On the surface of
both carbons the Mo formed oxides. In the model test reaction (acetic acid hydroconversion)
the catalytic activity of both carbon aerogels was enhanced by molybdenum. The more open
pore structure, higher concentration and finer Mo distribution, as well as its chemical form,
may all be responsible for the greater conversion and higher value products obtained with the
post-impregnated sample.

magyar

Article

PeerReviewed

info:eu-repo/semantics/article

text

http://real.mtak.hu/7758/1/Manuscript%20of%20the%20article_...

Nagy, Balåzs and Ábrahåm, Dåniel and Dobos, Gåbor and Madaråsz, Jånos and Onyestyåk, GyÜrgy and Såfrån, GyÜrgy and Geissler, Erik and Låszló, Krisztina (2014) MOLYBDENUM DOPED CARBON AEROGELS WITH CATALYTIC POTENTIAL. Carbon, 66. pp. 210-218. ISSN 0008-6223

http://real.mtak.hu/7758/

http://www.sciencedirect.com/science/article/pii/S000862231...

10.1016/j.carbon.2013.08.060