The ex situ exsolved Ni–Ru alloy from nickel–ruthenium co-doped SrFeO3−δ perovskite as a potential catalyst for CC and CO hydrogenation

Abstract

In this investigation, the synthesis of Ni and Ru co-doped SrFeO_3−δ (SrFe_1−x−yNi_xRu_yO_3−δ) perovskite materials was achieved through the utilization of sol–gel combustion followed by annealing treatment. The resulting annealed materials exhibited a cubic perovskite structure, and the introduction of Ni and Ru dopants led to an expansion in the unit cell parameters (lattice constant and volume). The exsolution of a bimetallic alloy nanoparticle from Ni and Ru co-doped SrFeO_3−δ was demonstrated through XRD, XPS, and TEM analyses. This exsolution process resulted in the formation of the Ni–Ru alloy well-dispersed on the brownmillerite structure (Sr₂Fe₂O₅). The exsolved Ni–Ru alloy from the parent perovskite has been studied as an effective catalyst for hydrogenation reactions. The active Ni–Ru species generated from the SrFe_0.9Ni_0.05Ru_0.05O_3−δ catalyst with 1.5% Ni and 2.6% Ru exhibit better catalytic performance in the hydrogenation of CC and CO functional groups. The catalyst achieved a maximum conversion of 98% for 1-octene, with the formation of hydrogenated products as the major products (60%). Furthermore, the reduced SrFe_0.9Ni_0.05Ru_0.05O_3−δ catalyst demonstrated potential for the selective hydrogenation of biomass model components, specifically furfural, with a conversion rate of 99% and a furfuryl alcohol selectivity of 91%. The uniform distribution of Ni–Ru species on the oxygen deficient perovskite support enhances the reducibility of Ni species in the presence of a trace amount of Ru by hydrogen spillover under the reaction conditions and improves the catalytic activity.