Previous work has shown that doping the TiC(001)
surface with early transition metals significantly affects CO<sub>2</sub>
adsorption and activation which opens a possible way to control this
interesting chemistry. In this work we explore other possibilities which
include non-transition metals elements (Mg, Ca, Sr, Al, Ga, In, Si, Sn) as well
as late transition metals (Pd, Pt, Rh, Ir) and lanthanides (La, Ce) often used
in catalysis. Using periodic slab models with large supercells and
state-of-the-art density functional theory (DFT) based calculations, we show that,
in all the studied cases, CO<sub>2</sub> appears as bent and, hence, activated.
However, the effect is especially pronounced for dopants with large ionic crystal radii. These can
increase desorption temperature by up to 230K, almost twice the value predicted
when early transition metals are used as dopants. However, a detailed analysis
of the results shows that the main effect does not come from electronic
structure perturbations but from the distortion that the dopant generates into
the surface atomic structure. A simple descriptor is proposed that would allow
predicting the effect of the dopant on the CO<sub>2</sub> adsorption energy in
transition metal carbide surfaces without requiring DFT calculations.
Density functional studies of functionalized graphitic materials with late transition metals for oxygen reduction reactions
