Facile gas-phase hydrodeoxygenation of 2,5-dimethylfuran over bifunctional metal-acid catalyst Pt–Cs_2.5H_0.5PW₁₂O₄₀

Abstract

2,5-Dimethylfuran is deoxygenated to n-hexane with 100% yield on bifunctional Pt/C–Cs2.5H0.5PW12O40 catalyst under very mild conditions (90 oC, 1 bar H2) in one-step gas-phase process. Proposed mechanism includes a sequence...

Hydrodeoxygenation of 2,5-dimethyltetrahydrofuran over bifunctional Pt–Cs2.5H0.5PW12O40catalyst in the gas phase: enhancing effect of gold

“…Biomass-derived furanic compounds are of interest as a renewable feedstock, which can be processed into a range of valueadded chemicals and green fuels via catalytic hydroconversion. [1][2][3][4][5][6][7][8] Hydrodeoxygenation (HDO) of furanic compounds using bifunctional metal-acid catalysis has been demonstrated to be an effective strategy to produce green fuels under mild conditions 3,4,6,[8][9][10][11][12] and references therein. The HDO over bifunctional metal-acid catalysts is much more efficient compared to the reaction over monofunctional metal catalysts.…”

“…The HDO over bifunctional metal-acid catalysts is much more efficient compared to the reaction over monofunctional metal catalysts. 11,12 Previously, we have reported HDO of a wide range of oxygenates in the gas phase to produce alkanes in the presence of bifunctional catalysts comprising Pt, Ru, Ni and Cu as metal components and Keggin-type heteropoly acids, with their activity decreasing in the order Pt > Ru > Ni > Cu. 13,14 Pt-CsPW comprising Pt and strongly acidic heteropoly salt Cs 2.5 H 0.5 -PW 12 O 40 (CsPW) has been reported to be a highly efficient catalyst for the HDO of 2,5-dimethylfuran (DMF) and 2,5dimethyltetrahydrofuran (DMTHF) to produce n-hexane with 100% yield at 90-120 C and ambient pressure.…”

“…13,14 Pt-CsPW comprising Pt and strongly acidic heteropoly salt Cs 2.5 H 0.5 -PW 12 O 40 (CsPW) has been reported to be a highly efficient catalyst for the HDO of 2,5-dimethylfuran (DMF) and 2,5dimethyltetrahydrofuran (DMTHF) to produce n-hexane with 100% yield at 90-120 C and ambient pressure. 11,12 The HDO of DMTHF over Pt-CsPW occurs through a sequence of hydrogenolysis, dehydration and hydrogenation steps catalysed by Pt and proton sites of the bifunctional catalyst (Scheme 1). These include the ring opening of DMTHF to form 2-hexanol on Pt sites followed by its dehydration on proton sites of CsPW to hexene, which is nally hydrogenated to n-hexane on Pt sites.…”

“…12 Other platinum group metals such as Pd, Ru and Rh, that have high selectivity to ring hydrogenation rather than ring hydrogenolysis, 2,7 have low activities in HDO of DMF and DMTHF. 11 Bimetallic PtAu and PdAu catalysts have been reported to have an enhanced performance in comparison to monometallic Pt and Pd catalysts, [15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30][31] for example, in hydrogenation, 16,21,29 hydrodesulphurisation, 27,28 oxidation, 22,24 isomerisation 15,19,30,31 and other reactions. 17,18,20,25,26 The enhancement of catalyst performance by addition of gold can be attributed to geometric (ensemble) and electronic (ligand) effects of the constituent elements in PtAu and PdAu bimetallic species.…”

“… 12 It is the facile dehydration of the secondary alcohol intermediate that drives the HDO process forward. 11,12 The rate-limiting step is either the ring hydrogenolysis or 2-hexanol dehydration depending on the ratio of accessible surface metal and acid sites Pt/H + . 12 Other platinum group metals such as Pd, Ru and Rh, that have high selectivity to ring hydrogenation rather than ring hydrogenolysis, 2,7 have low activities in HDO of DMF and DMTHF.…”