posted on 2021-08-26, 06:31authored byMuhammad
Fahad Arshad, Ling-Nan Wu, Achraf El Kasmi, Wu Qin, Zhen-Yu Tian
This
work reports
the thermochemistry calculations for solid-phase
periodic models of ten popular transition metal-based species. These
model structures were refined to stable geometry by geometric optimization
along with calculating the thermodynamic properties including enthalpy,
entropy, heat capacity at constant pressure, and Gibbs free energy
by DMol3 package via first-principles ab initio calculations.
The temperature-dependent thermochemistry values were converted to
a NASA seven-polynomial format. The behavior of different thermodynamic
parameters based on temperature was investigated and their comparative
analysis was done. A higher number of atoms tends to show higher thermodynamic
values. Moreover, these thermodynamic values agree reasonably well
with previously reported experimental and computational values. Metal
copper shows higher thermodynamic values as compared to its oxide.
The thermodynamic properties of lanthanum-based oxides have been newly
calculated through the ab initio method. Amorphous structures reveal
higher thermodynamic values compared to their crystalline counterparts.
A comparison between different transition metal-based species gives
a better understanding of the different crystalline structures and
their surface sites. These calculated thermodynamic data and polynomials
can be used for a variety of thermodynamic calculations and kinetic
modeling.