Assessing the potential of ZnO surfaces for Fischer-Tropsch synthesis using Car-Parrinello molecular dynamics

Abstract

We investigate the performance of non-polar ZnO surfaces as a catalyst in Fischer-Tropsch synthesis (FTS) through Car-Parrinello molecular dynamics. Economic and environmental concerns regarding the future of fuel production have increased interest in viable FTS catalysts. ZnO nanoparticles are promising catalytic candidates as they are environmentally safe and cost-effective. While the polar-surfaces of ZnO have been heavily studied, the non-polar surfaces have not. We computationally investigate the adsorption properties of various molecules vital to the FTS process over the pristine and defect non-polar ZnO surfaces. All molecular dynamics calculations were carried out with van der Waals exchange-correlation pseudopotentials in order to fully understand the adsorption process. From the results of the molecular dynamics simulations we propose that the ZnO dimer-defect surfaces can absorb and break the bonds of certain molecules, which is vital to the FTS process. We also observed weak interactions between both the dimer and edge-defect surfaces. These results show promise for ZnO defect-surfaces as FTS catalysts and showcase the effectiveness of molecular dynamics in visualizing the adsorption process.