Effects of TiO_(2) Support and Cobalt Addition of Ni/TiO_(2) Catalyst in Selective Hydrogenation of Furfural to Furfuryl Alcohol

An effect of phase compositions(rutile,Rut and anatase,Ant)of TiO_(2)supports on the selective hydrogenation of furfural to furfuryl alcohol was investigated.The 15%wt Ni/TiO_(2)catalysts were prepared by incipient impregnation method.The result showed that Ni supported on anatase-rutile mixed phase TiO_(2)(91%Rut and 9%Ant,A2)provided the highest furfuryl alcohol yield at 43.8%due to the relatively strong Ni-TiO_(2)interaction,its appropriate crystallite sizes,and high average pore sizes.Furthermore,the effect of cobalt as a promoter on Ni/TiO_(2)-A2 catalysts was studied.The result showed that the Ni-Co/TiO_(2)-A2 catalysts exhibited poorer catalyst performances compared to the monometallic Ni/TiO_(2),probably because addition of cobalt can lower the reduction temperatures of Ni/TiO_(2)and weaken the metal-support interaction.

Preparation and activity evaluation of NiMoB/-Al_2O_3 catalyst by liquid-phase furfural hydrogenation

Amorphous MoNiB/γ/-Al2O3 alloy catalysts were prepared by reducing NiCI2.6H20 and （NH4）6Mo7O24.4H2O supported on γ-Al2O3 with NaBH4 as reducing agent. Using liquid-phase hydrogenation of furfural （FFR） as a probe reaction, the activity of MoNiB/γ/Al2O3 was examined. Compared to NiB and NiMoB, NiMoB/γ-Al2O3 exhibited excellent activity and selectivity towards furfuryl alcohol （FFA）. After reaction for 3.0 h at 80 ℃ and 5.0 MPa in methanol, FFR conversion reached 99% with FFA yield of 91%. The effects of doping amount of Mo and calcination temperature before NaBH4 reduction on hydrogenation activity were also investigated. The optimum Mo/Ni atom ratio and calcination temperature were found to be 1：7 and 300 ℃, respectively. XRD patterns and SEM images indicated that NiMoB over the surface of γ-Al2O3 was amorphous and highly dispersed, which was responsible for the high thermal stability of the title catalyst.

Surface functionalized Pt/SnNb_(2)O_(6)nanosheets for visible-light-driven the precise hydrogenation of furfural to furfuryl alcohol

Photocatalytic upgrading of renewable biomass is a promising way to relieve energy crisis and environmental pollution.However,low photocatalytic efficiency and uncontrollable selectivity still limit its development.Herein,ultrathin SnNb_(2)O_(6)nanosheets with high dispersed Pt nanoparticles(Pt/SN)were successfully developed as an efficient photocatalyst for the precise hydrogenation of furfural(FUR)to furfuryl alcohol(FOL)under visible light irradiation and exhibited the high conversion of FUR(99.9%)with the high selectivity for FOL(99.9%).It was revealed that SN with only 4.1 nm thickness possess good separation ability of photo-generated carriers and abundant surface Lewis acid sites(Nb^(5+))which would selectively chemisorb and activate FUR molecules via the Nb···O=C coordination.Meanwhile,Pt nanoparticles would gather photo-generated electrons for greatly promoting the generation of active H species to support the hydrogenation of FUR to FOL.The synergistic effects between SnNb_(2)O_(6)nanosheets and Pt nanoparticles remarkably facilitate the photocatalytic performance for hydrogenation.This work not only confirms the great potential of ultrathin nanosheet photocatalyst with functional metal sites for precise upgrading of biomass but also provides an in-depth view to understand the surface/interface interaction between reactant molecules and surface sites of a photocatalyst.

Hydrogenation of Furfural to Furfuryl Alcohol over Co-B Amorphous Catalysts Prepared by Chemical Reduction in Variable Media

Five Co-B amorphous alloy catalysts were prepared by chemical reduction in different media, including pure water and pure ethanol as well as the mixture of ethanol and water with variable ethanol content, Their catalytic properties were evaluated using liquid phase furfural hydrogenation to furfuryl alcohol as the probe reaction. It was found that the reaction media had no significant influence on either the amorphous structure of the Co-B catalyst or the electronic interaction between metallic Co and alloying B. This could successfully account for the fact that all the as-prepared Co-B catalysts exhibited almost the same selectivity to furfuryl alcohol and the same activity per surface area （ Rs ）, which could be considered as the intrinsic activity, since the nature of active sites remained unchanged. However, the activity per gram of Co （ R^mH ） of the as-prepared Co-B catalysts increased rapidly when the ethanol content in the water-ethanol mixture used as the reaction medium for catalyst preparation increased. This could be attributed to the rapid increase in the surface area possibly owing to the presence of more oxidized boron species which could serve as a support for dispersing the Co-B amorphous alloy particles.

Selective conversion of furfural to cyclopentanol over cobalt catalysts in one step

A series of cobalt catalysts with different supports were prepared for the selective conversion of biomassderived furfural to cyclopentanol（CPL） in one step.The best CPLyield was 82 mol%at 160 ℃,2 MPa H2,4 h when cobalt was supported on ZrO2-La2O3.The supports were characterized by X-ray diffraction（XRD）and temperature-programmed desorption of ammonia（NH3-TPD）.The XRD results indicated that the more stable t-ZrO2 formed by doping La2O3.The amount of acid sites of the catalyst increased,too.The influences of parameters such as reaction temperature,hydrogen pressure,and reaction time on the catalytic activity were also investigated.The polymer formed during the reaction may cause the deactivation of the Co/ZrO2-La2O3 catalyst.This work provides a possibility to prepare the stable t-ZrO2and apply with cobalt metal for biomass valorization.