Mesoporous Ru(Co, Ni)B bimetallic amorphous alloy for CO2 hydrogenation to formic acid

Abstract

Amorphous metal alloy catalysts have attracted even-increasing attention owing to their high activity and selectivity. However, they are mainly prepared in ultrafine nanoparticles, which are easily gathered and challenging to separate. In this work, mesoporous Ru(Co, Ni)B bimetallic amorphous alloy catalysts with magnetic properties that can be easily recovered were synthesized via surfactant self-assembly. The as-prepared Ru1%CoB catalyst exhibited 578 μmol/g/h production rate and 99% selectivity to HCOOH during liquid phase CO2 hydrogenation owing to the unique amorphous alloy structure corresponding to the well-distributed, coordination-unsaturated, electron-enriched and synergistic active sites, which promoted the adsorption, activation, dissociation, and surface reaction of CO2 and H2. Moreover, the mesoporous channels also promoted the diffusion and adsorption of CO2 and H2. Besides, the Ru1%CoB catalyst also displayed good durability in CO2 hydrogenation owing to the robust stability against the crystallization of amorphous alloy, the collapse of mesopores, and the leaching of active sites.