Catalytic transfer hydrogenation/hydrogenolysis of 5-hydroxymethylfurfural (HMF) to valuable chemicals, 2,5-dimethylfuran (DMF), is realized over a carbon supported nickel-cobalt catalyst with formic acid as hydrogen donor. The highest DMF yield, 90.0%, is achieved at 210 °C under self-generated pressure. A reaction route involving 5-methylfurfural (5-MF) instead of 2,5-bis(hydromethyl)furan (BHMF) as an intermediate has been investigated, which is different from that when H 2 is used as hydrogen source in previous reports. The influence of the amount of formic acid is investigated on the conversion of HMF and the yield of DMF. The effectiveness of this strategy has also been used for the conversion of furfural to 2-methylfuran, another valuable chemicals.
Jifang Zhang,Chengcheng Suo,Jinde Sun,Wei Li,Sha Luo,Chunhui Ma,Shouxin Liu
In this study, C α –C β and C β –O bond cleavage of β-O-4 model compound (2-phenoxy-1-phenylethanol) were accomplished by electrocatalysis depolymerization process in deep eutectic solvents (DES) systems. We have investigated the application of Ni-Co/C catalysts on working electrode, which were synthesized with impregnation method. The Ni-Co/C with porous structure and abundant active sites, was shown an excellent electrocatalysis activity. Specific structure of Ni-Co/C could provide greatly efficient adsorption and desorption capacity to promote C α –C β and C β –O bond cleavage. Therefore, in this electrocatalysis depolymerization process, the highest depolymerization rate exceeded 90%. And the yields (and conversion rates) of products (including benzaldehyde, acetophenone, benzoic acid, phenol) can reach to 124.08 mg/g (25.05%), 23.29 mg/g (4.15%), 44.64 mg/g (7.83%), 30.3 mg/g (6.9%). Furthermore, the electrocatalysis mechanism of C α –C β and C β –O bond was investigated. The cleavage of C α –C β and C β –O bond was initiated by in situ generated free radicals through Ni-Co/C. Then, the cleavage of C α –C β and C β –O bond were occurred by ·OH and ·O 2 − . The results were showed that the C α –C β bond cleavage was more in line with the β-C elimination and free radical pathways, and C β –O bond cleavage was consistent with direct oxidative addition. The enhanced electrocatalytic efficiency of the low-cost Ni-Co/C electrocatalyst combined with its good chemical stability and selectivity, which offer a promising route for developing an efficient lignin depolymerization technology.