- Doping Pd/SiO2 with Na+: Changing the reductive etherification of CO to furan ring hydrogenation of furfural in ethanol
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The production of biofuels and chemicals by hydrogenation of furfural has attracted much attention recently. Herein the effect of Na+ doping on the catalytic performance of Pd/SiO2 in hydrogenation and reductive-etherification of furfural in ethanol was systematically studied. Two Pd/SiO2 catalysts with and without the modification by Na+ were prepared by impregnation and calcination. Their catalytic properties were compared for the hydrogenation of furfural and furfural diethyl acetal under mild conditions. The silanol groups on Pd/SiO2 catalysed the acetalization of furfural and alcohol and the resulted acetal underwent hydrogenolysis on Pd nanoparticles (NPs) with an average particle size of 8 nm, leading to a moderate yield (~58%) of furfuryl ethyl ether. Doping Na+ on Pd/SiO2 led to the diminishing of silanol groups as well as strong interaction between Na+ and Pd NPs. No acetalization occurred on Na+ modified Pd/SiO2 due to the exchange of H+ of Si-OH with Na+, thus the reductive etherification of CO group in furfural was completely inhibited. Meanwhile the hydrogenation of furan-ring over Na+ coordinated Pd NPs could proceed with very high selectivity (>90%) forming tetrahydrofurfural in high yield. Kinetics study on the hydrogenation of furfural diethyl acetal over Pd/SiO2 and Na+ doped Pd/SiO2 suggested that the Na+ greatly impeded the hydrogenolysis of C-O-C bond of acetal, while the hydrogenation of the furan ring took place selectively.
- Long, Yinshuang,Wang, Yun,Wu, Haihong,Xue, Teng,Wu, Peng,Guan, Yejun
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p. 25345 - 25350
(2019/08/28)
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- Facile synthesis of furfuryl ethyl ether in high yield: Via the reductive etherification of furfural in ethanol over Pd/C under mild conditions
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The one-pot synthesis of furfuryl ethyl ether (FEE) over Pd nanoparticles supported on TiO2, Al2O3, SiO2, and active carbon via the catalytic reductive etherification of furfural in ethanol was systematically studied. The Pd nanoparticles supported on SiO2, TiO2 and active carbon are all active for this novel process under mild reaction conditions, with Pd/C showing the highest selectivity to FEE. The effects of palladium loading, reaction temperature, and hydrogen pressure on the activity and selectivity of Pd/C have been investigated in detail. The results demonstrate that suitable Pd amount, low reaction temperature of about 60 °C, and low H2 pressure of about 0.3 MPa are favorable for the formation of the desired ether product. Under the optimized conditions, an unprecedented high yield of up to 81% of FEE was firstly obtained with the major by-products being furfuryl alcohol and 2-methyltetrahydrofuran. Compared with the conventional hydrogenation-etherification route via furfural alcohol as a reaction intermediate, the reductive etherification shows significant advantage in product yield because of its much lower reaction temperature that is required.
- Wang, Yun,Cui, Qianqian,Guan, Yejun,Wu, Peng
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p. 2110 - 2117
(2018/05/24)
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