Layered double hydroxides (LDHs) and their derivatives have been reported to be widely used as heterogeneous catalysts in various reactions. Herein, Ni-Fe LDHs with the controlled Ni/Fe molar ratios (2:1, 3:1, 4:1) were synthesized via an easy hydrothermal method, which were used to catalyze the selective reduction of biomass-derived furfural into furfuryl alcohol using 2-propanol as a H-donor under autogenous pressure and characterized using FT-IR, XRD, TGA, BET, SEM, NH 3 -TPD, and CO 2 -TPD. It was found that the LDH with a Ni/Fe molar ratio of 3:1 demonstrated the best catalytic activity among the LDHs with different Ni/Fe molar ratios, which showed 97.0% conversion of furfural and 90.2% yield of furfuryl alcohol at 140°C for 5 hr. This was attributable to the synergistic effect of acidic sites and basic sites of the catalyst.
Liu Jun-ru,Li Zhi-bo,Chen Ben,Chou Kuo-chih,Zhang Guo-hua
In order to improve the low ductility of the Mo-Ni alloy, Fe is added and the effects of Ni/Fe mass ratio on the densification behavior, microstructure evolution and mechanical properties of alloy were investigated. The experimental results show that when iron is added to 95Mo-5Ni alloy, the formation of brittle intermetallic phase δ -MoNi at the grain boundary is avoided. Meanwhile, the grain growth of Mo is also effectively inhibited in the sintering process. However, the addition of iron reduces the degree of densification of alloy since the activation effect of Ni is superior to that of Fe. From the experimental results, it could be concluded that the maximum hardness and bending strength are achieved by 95Mo-1.5Ni-3.5Fe alloy, which are HV 614 and 741 MPa, respectively. Combined with the analyses of bending fracture mechanism, the improvement relative to Mo-Ni alloy is likely attributed to the inhibition of the brittle phase.