Catalysis

Increasing energy demands and pollution have intensified the need for alternative renewable and clean sources of energy. Various chemical reactions like water splitting, carbon dioxide reduction, are aimed for producing these renewable fuels like H2 and CH4. There are also other reactions of importance such as nitrogen dioxide decomposition, nitrogen reduction reaction, etc. They either decompose the pollutants or produce chemicals for further processing. However, most of these reactions are not spontaneous and require some catalysts for their feasibility. The focus of our group is towards predicting efficient catalysts and photocatalysts (requiring light energy for driving the reaction) using first principles approach. Our group has worked on projects like mitigating CO oxidation for fuel cell applications and photocatalytic water splitting for hydrogen generation. We have utilized both thermodynamic and kinetic analysis in our studies, as both of them are necessary to have a complete understanding of the mechanism involved.

Pt bimetallic systems have extensively exhibited better catalytic activities and lower CO poisoning, however, complete elimination of Pt poisoning is still unresolved. We report for the first time that for Pt3Co/MgO(100), the preferred CO adsorption site inverts to Co from Pt. This inversion results from the better availability of empty anti-bonding d-states of Co atom in Pt3Co than those of the Pt atoms. This shall effectively address the issue of Pt-degradation by CO. Furthermore, Mars van Krevelan mechanism of CO oxidation on Pt3Co/Li-doped MgO(100), low reaction barrier of 0.11 eV predicts good reaction kinetics. Li-doped MgO(100) has a spontaneous activation of oxygen.

References

  1. R. Kumar, D. Das, and A. K. Singh, C2N/WS2 Van der Waals Type-II Heterostructure as a Promising Water Splitting Photocatalyst J. Catal. 359, 143 (2018)
  2. R. Ahmad and A. K. Singh, Simultaneous Site Adsorption Shift and Efficient CO Oxidation Induced by V and Co in Pt Catalyst J. Phys. Chem. C 121, 12807 (2017)
  3. R. Ahmad, and A. K. Singh, Pt Poisoning Free Efficient CO Oxidation on Pt3Co Supported on MgO(100): An Ab Initio Study, ACS Catalysis 5, 1826 (2015)
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