M/SiO2 (M = Co or Ni) nanoparticles prepared by magnetron sputtering deposition method for CO2 valorization by reverse water gas shift reaction

In this work, magnetron sputtering deposition method was used to prepare very small Co and Ni nanoparticles supported on SiO2 catalysts and applied to reverse water gas shift (RWGS) reaction for CO2 valorization. The results obtained in the optimized reaction condition are presented in Figure 1. At this condition, Co nanoparticles reached a CO2 conversion next to 60 and 50% at 800°C (for 0.4 and 0.5% of metal loading, respectively) and Ni nanoparticles reached CO2 conversion near to 60 and 75% at 800°C (for 0.6 and 1.4% of metal loading, respectively). Co and Ni nanoparticles were tested in a reaction condition to study CH4 formation with two consecutive cycles and it was observed that there is no CH4 formation when Co nanoparticles are employed and for Ni nanoparticles CH4 is formed just in the first cycle of reaction. The results suggest that Co and Ni materials prepared by magnetron sputtering deposition method are promising for CO2 valorization by RWGS reaction. The authors gratefully acknowledge support of the RCGI – Research Centre for Gas Innovation, hosted by the University of São Paulo (USP) and sponsored by FAPESP – São Paulo Research Foundation (2014/50279-4) and Shell Brazil. The work was also supported by CNPq (Project 439389/2016-0 and Process 150623/2017-8).