Communication
ChemComm
We thank the Deanship of Scientific Research at King Faisal
University, Saudi Arabia for the financial support under Nasher
Track (Grant No. 206004).
Conflicts of interest
Scheme 1 Reaction network for HDO of DMF over Pt–CsPW.
There are no conflicts to declare.
2 2
conversion (5%). Interaction of 2-hexanol with CsPW in H or N
yielded a mixture of 1-hexene and 2-hexene (cis and trans isomers)
at 499% alcohol conversion. The reaction of 2-hexanol over Pt–
Notes and references
1 (a) A. Corma, S. Iborra and A. Velty, Chem. Rev., 2007, 107, 2411–2502;
(
b) Y. Rom ´a n-Leshkov, J. N. Chheda and J. A. Dumesic, Science, 2006,
12, 1933–1937; (c) R. M. West, Z. Y. Liu, M. Peter and J. A. Dumesic,
CsPW in H produced n-hexane in 499 yield as expected. DMTHF
2
3
over CsPW alone gave mainly cracking products at 2% DMTHF
conversion. The monofunctional Pt/C catalyst in the absence of
CsPW had a very low activity in DMTHF hydrogenolysis to form
ChemSusChem, 2008, 1, 417–424; (d) G. W. Huber, J. N. Chheda,
C. J. Barrett and J. A. Dumesic, Science, 2005, 308, 1446–1450;
(
e) Z. J. Brentzel, K. J. Barnett, K. Huang, C. T. Maravelias,
J. A. Dumesic and G. W. Huber, ChemSusChem, 2017, 10, 1351–1355;
f ) J. Kang, A. Vonderheide and V. V. Guliants, ChemSusChem, 2015, 8,
2-hexanol in 88% selectivity at 1.6% DMTHF conversion, with only
(
8
% of hexane being formed at 90 1C. Bifunctional Pt/C + CsPW
3044–3047; (g) R. C. Runnebaum, T. Nimmanwudipong, J. Doan,
D. E. Block and B. C. Gates, Catal. Lett., 2012, 142, 664–666;
catalysts had a good activity in HDO of DMTHF to give 499%
hexane selectivity at 44% DMTHF conversion at 90 1C and 71%
conversion at 100 1C. These tests confirm the hydrogenation–
dehydration–hydrogenation sequence of reaction steps in
Scheme 1 and demonstrate the importance of both Pt and H
sites for the HDO reaction. Previous reports
study show that the initial hydroconversion of DMF on Pt sites
strongly favours the ring opening over the ring saturation, with
the molar ratio of the primary reaction products [2-hexanone]/
(h) J. Kang, X. Liang and V. V. Guliants, ChemCatChem, 2017, 9, 282–286.
2
3
4
5
6
7
8
Y. L. Louie, J. Tang, A. M. L. Hell and A. T. Bell, Appl. Catal., B, 2017,
202, 557–568.
V. Vorotnikov and D. G. Vlachos, J. Phys. Chem. C, 2015, 119,
10417–10426.
+
A. Corma, O. de la Torre, M. Renz and N. Villandier, Angew. Chem.,
Int. Ed., 2011, 50, 2375–2378.
J. Yang, S. Li, L. Zhang, X. Liu, J. Wang, X. Pan, N. Li, A. Wang,
Y. Cong, X. Wang and T. Zhang, Appl. Catal., B, 2017, 201, 266–277.
H. Goto, A. Takagaki, R. Kikuchi and S. T. Oyama, Appl. Catal., A,
2017, 548, 122–127.
F. Xue, D. Ma, T. Tong, X. Liu, Y. Hu, Y. Guo and Y. Wang,
ACS Sustainable Chem. Eng., 2018, 6, 13107–13113.
H. Althikrallah, C. Kunstmann-Olsen, E. F. Kozhevnikova and
I. V. Kozhevnikov, Catalysts, 2020, 10, 1171, DOI: 10.3390/
catal10101171.
2,6,8
as well as this
[DMTHF] E 10. Moreover, the turnover rate of DMF hydroconver-
sion in the gas phase on monofunctional Pt/C is 2400 times
greater than that of DMTHF at 80 1C and 1 bar H . This indicates
that reaction pathway (1) should dominate by far over pathway (2)
8
2
9
D. M. Alonso, J. Q. Bond and J. A. Dumesic, Green Chem., 2010, 12,
(Scheme 1).
1493–1513.
In conclusion, Pt–CsPW catalyst deoxygenates DMF to n-hexane 10 M. A. Alotaibi, E. F. Kozhevnikova and I. V. Kozhevnikov, J. Catal.,
2
012, 293, 141–144.
with 100% yield under very mild conditions (90 1C, 1 bar H
pressure) in the gas phase. Mild reaction conditions exclude
2
1
1 M. A. Alotaibi, E. F. Kozhevnikova and I. V. Kozhevnikov,
Chem. Commun., 2012, 48, 7194–7196.
n-hexane isomerisation allowing complete conversion of DMF to 12 K. Alharbi, E. F. Kozhevnikova and I. V. Kozhevnikov, Appl. Catal., A,
2
015, 504, 457–462.
alkane without carbon backbone alteration. The bifunctional Pt–
CsPW catalyst is much more efficient than monofunctional Pt
catalysts operating under harsh conditions.
in a flow system over Pt–CsPW is more efficient than the corres-
ponding liquid-phase batch reaction. The proposed reaction net-
1
3 S. Itagaki, N. Matsuhashi, K. Taniguchi, K. Yamaguchi and
N. Mizuno, Chem. Lett., 2014, 43, 1086–1088.
4,5,7
The gas-phase HDO 14 K. Alharbi, W. Alharbi, E. F. Kozhevnikova and I. V. Kozhevnikov,
ACS Catal., 2016, 6, 2067–2075.
1
1
5 T. Okuhara, N. Mizuno and M. Misono, Adv. Catal., 1996, 41, 113–252.
6 I. V. Kozhevnikov, Chem. Rev., 1998, 98, 171–198.
work for the HDO of DMF includes a sequence of hydrogenolysis, 17 M. A. Alotaibi, E. F. Kozhevnikova and I. V. Kozhevnikov, Appl.
+
Catal., A, 2012, 447–448, 32–40.
8 A. Alazman, D. Belic, E. F. Kozhevnikova and I. V. Kozhevnikov,
J. Catal., 2018, 357, 80–89.
hydrogenation and dehydration steps catalysed by Pt and H sites
1
in a bifunctional catalyst. Combined action of metal and acid sites
is essential for the effectiveness of this process. Facile dehydration 19 P. B. Weisz, Adv. Catal., 1962, 13, 137–190.
2
0 The reaction was carried out in a stainless steel autoclave at 90–140 1C,
of secondary alcohol intermediate, 2-hexanol, on proton sites is an
effective driving force of the HDO process by bifunctional metal-
acid catalysis.
2
0 bar H pressure (RT) and 600 rpm stirring speed using decane as a
solvent. Under such conditions, the reaction did not depend on the
stirring speed, and hence was not limited by external diffusion.
2
Chem. Commun.
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