Ru nanoparticles in ionic liquids confined by silica gel: A high active iongel catalyst for low temperature water-gas shift reaction

Abstract

In this study, two different kinds of iongel catalysts were prepared by the dispersion of Ru nanoparticles in 1-Butyl-3-methylimidazolium tetrafluoroborate ([BMIM]BF4) with a particle size of 2.4 nm in tetraethoxy orthosilicate (TEOS), followed by the hydrolysis of TEOS under acidic or basic conditions. The iongel catalyst prepared under acidic conditions had larger surface area, pore volume and higher stability to confine the active component in the silica matrix than that prepared under basic conditions. Thus, the iongel catalyst prepared under acidic conditions showed much higher catalytic activity. The highest CO conversion of 37.8% was achieved at 140 °C over the iongel catalyst prepared under acidic conditions, significantly higher than the 10% achieved on the iongel catalyst prepared under basic conditions. More importantly, it also showed high stability. Besides the superior texture properties of the iongel catalyst prepared under acidic conditions, the stability of Ru nanoparticles also contributed to its high catalytic activity and stability over the iongel catalyst prepared under acidic conditions.