Active γ –Alumina -Supported Ru Nanoparticles for CO2 Hydrogenation Reaction

Abstract

A series of alumina supported Ru nanoparticles (Ru γ -Al2O3-x (x=2-10 Ru wt%) was synthesized using the ethylene glycol reduction method. XRD, TEM, EDX, H2-chemisorption, XPS and H2-TPD analytical techniques were used to understand the physiochemical nature of alumina supported Ru nanoparticles. All the well-characterized Ru#Al2O3-x (x=2-10 Ru wt%) catalysts were used for high-pressure CO2 hydrogenation to formic acid synthesis. A clear correlation was recorded between the physiochemical properties of developed catalysts and the molar quantity of formic acid. Among all the developed catalysts, Ru#Al2O3-2 catalyst with or without ionic liquid reaction medium gave a good molar quantity of formic acid. Application of ionic liquid was also expanded, and ionic liquid medium appeared as a good solvent system as compared to the amine solvent system, which not only provides better solubility of reactants and catalysts but also found useful in the easy recovery of formic acid after the completion of the reaction. The catalyst recycled seven times with easy product isolation stem to make this system very useful and fulfill the requirement of sustainable chemistry.