01/10/2023

مشاري بن عياد العتيبي

مشاري بن عياد العتيبي
دكتوراه
الكيمياء الفيزيائية
University of Liverpool

مجال
التميز

تميز دراسي وبحثي

 

 

البحوث المنشورة

 

البحث (1):

 

عنوان البحث:

Efficient hydrodeoxygenation of
biomass-derived ketones over bifunctional Pt-polyoxometalate catalyst

رابط الوصول:

Link

تاريخ النشر:

May
2012

موجز عن البحث:

Acidic heteropoly salt Cs2.5H0.5PW12O40
doped with Pt nanoparticles is a highly active and selective catalyst for
one-step hydrogenation of methyl isobutyl and diisobutyl ketones to the
corresponding alkanes in the gas phase at 100 °C with 97–99% yield via
metal-acid bifunctional catalysis.

 

 

البحث (2):

 

عنوان البحث:

Hydrogenation
of methyl isobutyl ketone over bifunctional Pt-zeolite catalyst

رابط الوصول:

Link

تاريخ النشر:

June
2012

موجز عن البحث:

Abstract:

Methyl isobutyl ketone
(MIBK) can be viewed as a key intermediate for the conversion of
biomass-derived acetone – the by-product of biobutanol production – to
transportation fuel. Zeolite H-ZSM-5 doped with Pt nanoparticles was found to
be a highly efficient catalyst for gas-phase hydrogenation of MIBK to
methylpentanes with >99% yield at 200 °C. The reaction proceeds via
bifunctional metal-acid catalysed pathway involving MIBK hydrogenation to
4-methyl-2-pentanol (MP-ol) on metal sites followed by MP-ol dehydration on
acid sites to form olefin and finally olefin hydrogenation to 2-methylpentane
(2MP) on metal sites, with all three steps occurring on a single catalyst
bed. 2MP thus obtained underwent isomerisation over bifunctional Pt/H-ZSM-5
catalyst to give a mixture of 2- and 3-methylpentanes in a ratio of 83:17.
The catalyst did not show any deactivation for at least 16 h on stream.

 

 

 

البحث (3):

 

عنوان البحث:

Deoxygenation
of propionic acid on heteropoly acid and bifunctional metal-loaded heteropoly
acid catalysts: Reaction pathways and turnover rates

رابط الوصول:

Link

تاريخ النشر:

August
2012

موجز عن البحث:

Abstract:

Reaction pathways of the gas-phase
deoxygenation of propionic acid in the presence of heteropoly acid and
bifunctional metal-loaded heteropoly acid catalysts were investigated in a
fixed-bed reactor at 250–400 °C in flowing H2 or N2.
Silica-supported H3PW12O40 (HPW) and bulk
acidic salt Cs2.5H0.5PW12O40
(CsPW), both in H2 and in N2, exhibited ketonisation
activity between 250 and 300 °C to yield 3-pentanone, CsPW being more
selective than HPW. At 400 °C, HPW and CsPW were active for
decarbonylation and decarboxylation of propionic acid to yield ethene and
ethane, respectively. Loading Pd or Pt onto CsPW greatly enhanced
decarbonylation in flowing H2 but had little effect in N2.
Similar performance exhibited Pd/SiO2 and Pt/SiO2,
giving almost 100% selectivity to ethene in H2. These results are
consistent with hydrodeoxygenation of propionic acid on Pd and Pt, suggesting
that hydrogenolysis of Csingle bondC bond plays essential
role. In contrast to the Pd and Pt catalysts, Cu catalysts, Cu/CsPW and
Cu/SiO2, were both active in hydrogenation of Cdouble bond; length as m-dashO bond to yield propanal and
1-propanol. Turnover rates of propionic acid conversion on metal catalysts
followed the order Pd > Pt > Cu for both
CsPW-supported and silica-supported metal catalysts.

 

 

المؤتمرات العلمية:

 

المؤتمر (1):

 

عنوان المؤتمر:

15th International Congress on Catalysis

تاريخ الإنعقاد:

July
2012

بلد
ومكان الإنعقاد:

Munich,
Germany

طبيعة المشاركة:

Oral
presentation

عنوان المشاركة:

Gas-phase
deoxygenation and hydrogenation of propionic acid on heteropoly acid
catalysts

الملخص

The
main pathways of deoxygenation of propionic acid under the conditiones
studied involve: (1) ketonisation over heteropoly acid (HPA), (2)
decarbonylation over Pd and Pt and (3) hydrogenation over Cu.

 

From
the practical point of view, it may be desirable to produce the ketonisation
products with carbon backbone upgrade (Cn → C2n-1)
over CsPW at 250 – 300 oC in hydrogen-free system, as well as the
Cn hydrogenation products (aldehydes and alcohols) without
carbon loss using Cu catalysts. On the other hand, Pd and Pt catalysts
possessing high hydrodeoxygenation activity via decarbonylation pathway allow
producing the Cn-1 alkenes.

المؤتمر (2):

 

عنوان المؤتمر:

Saudi International
Conference 2011

تاريخ الإنعقاد:

June
2011

بلد
ومكان الإنعقاد:

Coventry,
UK

طبيعة المشاركة:

Poster

عنوان المشاركة:

Hydrogenation of carboxylic acids over
Heteropoly acid catalysts

الملخص

The
more stable catalysts based on CsPW retain their primary (Keggin) and
secondary structures upon carboxylic acid (hydro)deoxygenation in the gas phase.
CsPW is active for acid ketonisation, Cu/CsPW for hydrogenation, whereas
Pd/CsPW and Pt/CsPW for decarbonylation. Turnover rates followed the order Pd > Pt > Cu.

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