P-induced electron transfer interaction for enhanced selective hydrogenation rearrangement of furfural to cyclopentanone

Optimizing the intrinsic activity of non-noble metal by precisely tailoring electronic structure offers an appealing way to construct cost-effective catalysts for selective biomass valorization.Herein,we reported a P-doping bifunctional catalyst(Ni-P/mSiO_(2))that achieved 96.6%yield for the hydrogenation rearrangement of furfural to cyclopentanone at mild conditions(1 MPaH_(2),150°C).The turnover frequency of Ni-P/mSiO_(2)was 411.9 h^(-1),which was 3.2-fold than that of Ni/mSiO_(2)(127.2 h^(-1)).Detailed characterizations and differential charge density calculations revealed that the electron-deficient Niδ+species were generated by the electron transfer from Ni to P,which promoted the ring rearrangement reaction.Density functional theory calculations illustrated that the presence of P atoms endowed furfural tilted adsorb on the Ni surface by the C=O group and facilitated the desorption of cyclopentanone.This work unraveled the connection between the localized electronic structures and the catalytic properties,so as to provide a promising reference for designing advanced catalysts for biomass valorization.

Regulating the nanoscale intimacy of metal and acidic sites in Ru/γ-Al_(2)O_(3)for the selective conversions of lignin-derived phenols to jet fuels

Catalytic hydrodeoxygenation(HDO)of biomass-derived oxy-compounds to advanced hydrocarbon fuels usually requires bifunctional catalysts containing metals and acidic sites.The appropriate tuning of metal and/or acidic active sites at interfaces of bifunctional catalysts can significantly improve catalyst activity and product selectivity.Here,4-trifuoromethyl salicylic acid(TFMSA),as a hydrothermal stable organic acid,was employed to tailor the bifunctional interface of Ru/γ-Al_(2)O_(3)to enhance the catalytic performance on converting lignin-derived phenols to jet fuel range cycloalkanes.More than 80%phenol was converted into cyclohexane at 230°C for 1 h over Ru/γ-Al_(2)O_(3)modified by TFMSA,which was about three times higher than that over unmodified Ru/γ-Al_(2)O_(3).X-ray diffraction(XRD),Transmission electron microscope(TEM),H2 chemisorption,and energy dispersive X-ray spectroscopy(EDS)elemental mapping results indicated that Ru nanoparticles and TFMSA were well distributed onγ-Al_(2)O_(3),and a nanoscale intimacy between Ru and TFMSA was reached.Meanwhile,Fourier transform infrared spectroscopy after pyridine adsorption(Py-FT-IR)analysis proved that Brønsted acidic sites on the catalytic interfaces of TFMSA modified Ru/γ-Al_(2)O_(3)had been improved.Moreover,the kinetic and density functional theory(DFT)results suggested that the synergistic effects of adjacent Ru nanoparticles and acidic sites were crutial for promoting the rate-limiting conversion step of phenol HDO to cyclohexane.