(399g) CO2 Activation on Zr-Decorated, Cu Nanoparticles

Authors: 
Austin, N., University of Pittsburgh
Mpourmpakis, G., University of Pittsburgh
Cu-based catalysts are good candidates for the conversion of CO2, a greenhouse gas, into fuels and chemicals, such as formic acid and methanol. In this work, density functional theory calculations have been applied to investigate the role of Zr decoration on the structural and electronic properties of Cu55 nanoparticles and its behavior towards CO2 adsorption. The Zr decoration is thermodynamically preferred on the corner (surface) sites of the nanoparticles. This decoration results in strong CO2 chemisorption which does not occur in the case of the monometallic Cu55. By further increasing the Zr composition in Cu55-xZrx nanoparticles (with x=2-12) we observed a significant enhancement in the CO2 adsorption starting at the composition Cu47Zr8. The CO2 molecule is shown to be activated upon chemisorption on the Zr-decorated, Cu-based nanoparticles, transitioning from a linear to a bent configuration. Charge transfer from the nanoparticle to the CO2 molecule was found to be responsible for the observed activation. Furthermore a linear relationship between the total charge transferred to CO2 and the ionization potential (IP) of the nanoparticles was observed. Finally, a model has been developed that is able to predict Cu nanoparticle morphologies with Zr decoration over various nanoparticle sizes, which could potentially show enhanced CO2 adsorption and activation.