Selective aqueous phase hydrogenation of xylose to xylitol over SiO2-supported Ni and Ni-Fe catalysts: Benefits of promotion by Fe

• Published in: Applied catalysis. B, Environmental Environmental, 2021-12, Vol.298, p.120564, Article 120564
• Main Authors: Sadier, Achraf, Shi, Dichao, Mamede, Anne-Sophie, Paul, Sébastien, Marceau, Eric, Wojcieszak, Robert
• Format: Article
• Language: English
• Subjects: Bimetals; Biomass valorization; Catalysis; Catalysts; Catalytic activity; Chemical Sciences; Deactivation; Hydrogenation; Iron; Kinetics; Leaching; LEIS; Metal particles; Nanoparticles; Ni-Fe bimetallic particles; Nickel; Organic chemistry; Silica; Silicon dioxide; Surface layers; Xylitol; Xylose
• ISSN: 0926-3373; 1873-3883
• DOI: 10.1016/j.apcatb.2021.120564

[Display omitted] •Stable and selective bimetallic Ni-Fe catalyst was study in the aqueous phase hydrogenation of xylose to xylitol.•The benefits of using Fe as a promoter of Ni: increasing the catalyst activity and chemical stability of the catalyst.•Reduced Fe at the surface increased both the first-order apparent rate constant and the adsorption constant of xylose.•The restructuring of the bimetallic nanoparticles occurred as the metal particles sizes and the Fe proportion in the surface layers increased. A monometallic Ni and a bimetallic Ni-Fe catalyst were used in the aqueous phase hydrogenation of xylose in batch conditions (T = 50–150 °C, PH2 = 10–30 bar, xylose mass fraction in water = 3.7–11.0 wt.%) to evidence the benefits of promoting Ni by Fe. The activity of the catalysts increased with temperature, but a temperature of 80 °C allowed minimizing nickel leaching at full conversion. The presence of reduced Fe at the surface of the bimetallic nanoparticles increased both the first-order apparent rate constant and the adsorption constant of xylose. The catalytic activity of Ni/SiO2 strongly declined and no deactivation was found for the Ni-Fe catalyst. A restructuring of the bimetallic nanoparticles took place, as the size of the metal particles and the Fe proportion in the surface layers increased, suggesting a flattening and coalescing of the particles over the silica surface.