First-principles study on the design of nickel based bimetallic catalysts for xylose to xylitol conversion.

A significant challenge for effective biomass utilization and upgrading is catalysis. This research paper focuses on the conversion of xylose into xylitol, a valuable chemical used in the pharmaceutical and food industries. The primary objective is to design more efficient and cost-effective catalysts for this conversion process. The study investigates the use of Ni-bimetallic catalysts by employing a first-principles technique. Catalyst models derived from subsets of Ni (111) surfaces with various transition metals (M = Ti, V, Cr, Fe, Co, and Cu) are examined. The catalyst surfaces are screened based on the rate-determining step (RDS) involved in the conversion of xylose to xylitol, with Ni (111) serving as a reference. Electronic structure calculations are used to analyze the activities of the investigated Ni-bimetallic catalysts relative to the RDS. The results show that certain bimetallic surfaces exhibit significantly lower kinetic barriers compared to the Ni (111) surface. The hydrogenation process when investigated using different transition state paths, reveals that hydrogenation commences at the carbon atom of the carbonyl group of xylose after the ring-opening step. Stability segregation tests demonstrate varying behaviors among the screened catalysts, with Ni (111)/Cr/Ni showing greater stability than Ni (111)/Co. This study sheds light on the theoretical design of catalysts for xylose conversion, providing insights for the development of more efficient and active catalysts for industrial applications. The research highlights the significance of theoretical methodologies in tailoring catalyst surfaces to optimize their performance in biomass upgrading.